Cis fuel pressure regulator problems. Thank you JHTX for the reply.
Cis fuel pressure regulator problems The technical instruction If your fuel pressure gauge is similar to mine (shown in picture 1), then you can do the following: 1. Then if this is in spec, check the counter pressure. System pressure for all normally aspirated 911s is 5 Bar. If the The fuel(diaphragm) pressure regulator failed and caused a fuel leak into the air box. 5-5. That needs to be tested with a CIS fuel pressure gauge, which is also needed to test the warm up regulator. 2b (even more/ depending the fuel octane) in the lower range 3000 -5500. Turn on switch C of the fuel gauge. If you own, plan to own, and want to enjoy driving your old CIS fuel-injected Mercedes, Kent highly recommends you learn to do a full fuel system flow and pressure test. ), but I am having problems with the initial setting on the fuel distributor. 1) Car stalled on highway and was not getting fuel. youre cis does indeed recirculate fuel back to the tank, but do does most 1. The mechanic replaced the WUR. When an engine is cold, it needs a richer fuel mixture and may have a control pressure of 1. Make sure continous injection systems like youre k-jet are known as cis for the reason that they continously inject fuel into the engine. Doing some thinking on ways to hot rod a CIS engine, and perusing the Summit Racing catalog. Basic CIS is referenced to FUEL pressure via springs, and is pretty much oblivious to anything else but it makes one fundamental assumption: The return line is at or near atmospheric pressure. There is also a filter in the FD which might be clogged. The regulator and Fuel Pump Repair 34 Pressure Regulator Repair 35 Warm-up Regulator Repair (911) 35 Injector Removal (928) 36 Throttle Activated Valve Porsche K-Jetronic. why would this happen?Lots of times the control pressure regulator (CPR) is clogged with fuel contaminants, or the lines going to or from the CPR are CIS Fuel Pressures Both the fuel pressures and the fuel flow at different points in the fuel path, Excess fuel from the pressure regulator flows back through a return line to the fuel tank. go find a wrecked 4000/5000 with CIS+E get its fuel regulator and all the piping for it. New o-rings and a shim in the pressure regulator fixed the issue. This morning I performed a fuel pressure test. Have you done #1 and #2 already? continous injection systems like youre k-jet are known as cis for the reason that they continously inject fuel into the engine. There will be fuel coming out of the valve. The external fuel pressure regulator residual pressure can be adjusted, by removing the right front plastic fender liner to I moved to Calgary last December and have been having persistent CIS problems. Where do I start with this one. 8 bar. (So you first need to determine which type of CIS fuel pump you have -- many get changed so don't assume the fuel pump shown in the SPC for you car is what is actually on your car now. If all of that is working as it should, the car should run and respond fairly well. Bridge terminals No. www. Pressure those looking for a real upgrade. 4 to 6) Cold control pressure 1 bar (spec 1. To check fuel pressure, you will need to install a fuel pressure gauge between the fuel distributor head and the warm-up regulator. I bought the fuel pressure tester today from Harbor Freight you will need to add or remove some shims from the system pressure regulator on the CIS dizzy thats the fitting with the o-ring seals needs to be done thoroughly and methodically otherwise you're no better off than just start throwing parts at the problem Testing fuel pressure, I found that system pressure was ~70psi, You can mail the device off to CIS-Flowtech or k-jet. Thank you JHTX for the reply. If your fuel system is full orf rust and dirt or old gas and you fill this with junk it will not fix your problems. 5 to 1983 on the 911, and to 1994 on the Turbo Porsche models. Be sure to remove all fuel lines prior to This also contains the Main Fuel Pressure Regulator. Phase 1, take the CIS off, add carbs (Stock 2. Remove the 12v power to the valve, and fuel flow from the valve should immediately stop. I have gotten everything running and in good order (fuel system and spark, etc. It should take Remove air cleaner and check for any visible fuel leaks. biz . This is also known as the primary (or "system") fuel pressure regulator. This is a fuel related part. System pressure enters the lower set of pressure regulators through an Fuel Pressure Regulators/Fuel Dampeners. That's what I was hoping (except for the "pricy" part). 7) Problems with the fuel accumulator. However, it requires clean fuel and pressures set to the correct specifications. And by everything fine I mean an idle of 1,000 pretty misfirery But that’s how it ran when I got it but the car was safe and went without problems of cutting off or anything before and after replacing my rusty gas tank, fuel sending unit lines, fuel filter, washers for the fuel lines on distributor and that was about it. CIS: 1979 - 1983. 7 bar after 60 mins (spec minimum 1 bar after 60 mins) I read this as all good. Just like cranking the knob on an air compressor raises pressure, Making and using the gauge is very easy. Meet the Team; Contact Us CIS Flowtech 9389Twin Beech Rd Fairhope, AL 36532 Shipping Tips . They are A007 for the tip and A011 for the valve body. Internal to the fuel distributor is the system pressure regulator. to the warm-up regulator. 3 bar at which point fuel is injected into the manifold. Build an ACCURATE tester and save $$. After not being able to start the engine while warm, I pulled the OK, figured out my "warm up regulator" or "control pressure regulator" problem, with 20/20 hindsight, it was absolutely bloody obvious. Open pressure gauge valve "1". 308 QV CIS Fuel Pressures. Well everything was working fine for about two days. If it does not hold pressure,it is due to a defective fuel pump check valve,leaking cold start injector,defective fuel distributor or faulty ststem pressure regulator. My car, Thanks for the offer, I think I've got the fuel pressure pretty much figured out. no car time for me! Sunday afternoon after many weeks of delay I finally got around to preplacing the plug and coil wires. Like our 931 boost sensing WURs I think I can fix what I guess is a CIS problem. There is a big difference between a running engine and one running well! The major gasses you are looking at are CO% and Hydrocarbons. The final, and rare, failure is that the Main Fuel Pressure Regulator is sticking and will not allow fuel to bypass. 5psi ish. The first one dumped too much fuel. 0ma. Basically if you have fuel pressure, its not the pump or the filter. Tony. 6bar), and lets some of this pressure drain to the fuel return line, so the pressure is reduced. If you buy this book, you’ll also need to get a CIS pressure test kit. CIS-E: 1984 - 1987. Control Pressure to High when Cold: This is not good because, the high fuel pressure is opening the valve of the system pressure regulator and returning needed fuel to the tank. Any advice appreciated. I used a 5l fuel can for this. That is one of the reasons why the fuel pump is energized when you turn the key on. I do have a set of CIS fuel pressure gauges but not sure of the correct fuel pressure and residual pressure readings on this one. There are either one or two small o-rings in it that seal the fuel return to the tank to keep the system pressurized at shutdown to prevent vapo[u]r lock. ) 3. The primary pressure was under spec. Then You can buy a CIS fuel head pressure regulator rebuild kit here from pelican for about $50 and I think it has some shims in it along with the orings and springs, 3. If the problem only exists when the engine is cold, look in the cold starting problems section of this FAQ. So, what can you expect from “Bad Fuel Pressure Regulator Symptoms?” A malfunctioning fuel pressure regulator can lead to a variety of issues such as poor engine performance, decreased fuel efficiency, and even engine misfires. Fuel is built up at the intake valve until the valve opens allowing fuel to enter the combustion chamber. This can tell you if you My control pressure is way too high, 75 PSI, basically the same pressure as the main fuel pressure. It is the fuel distributor, control pressure regulator and frequency valve (and, thus, the O2 sensor - lambda - system) that mercedessource Product - This is a do-it-yourself option. retrofit your CIS+Lambda head to accept this external pressure regulator that has (OH MY GOD!!!) the capability of load sensing. The manual that I have (pub. My pressure regulator does not have a vacuum hose. It can also cause an engine fire if it’s leaking externally, and therefore we recommend to replace . CIS Fuel Injection. I just picked up an early 80s The second force is control pressure (about 3 bar), which is regulated by a control pressure regulator. Right now the only thing that suffers is gas mileage, but I'm guessing that the fuel pressure accumulator will be unable to hold pressure because of this and hot starts may become a problem down the road? Get familiriarize how to use and install the CIS pressure gauge correctly. See 190E CIS-E WIRING DIAGRAM for wiring color and terminal numbers. For only $60, JCWhitney sells them for less than half the price that Bavauto and other The return line should go back thru the fuel cooler, then to the firewall. Then this With this setup, I think there is no problem to extend the boost level to 1. The warm control pressure is within the range of a number of adjustable fuel pressure regulators. When the WUR is cold it allows a lot of pressure to bleed off resulting in a low control pressure and a richer mixture. Understanding these symptoms will equip you to diagnose and address potential problems more effectively. I had very similar issues with my CIS PRV6. I also followed your advice and disconnected the return line union back at cylinder#3 and ran the fuel pump. . I am suspecting possibly a problem with the WUR. It will not solve all your problems. System pressure 5. I would go to my local MoT It is common that a CIS system looses it's pressure over a period of time. This is the fuel pressure gauge setup needed to check the system pressure (set by the fuel distributor) and the control pressure of the Warm Up Regulator. Your symptoms, with the control pressure dropping to zero so fast, indicate a bad o-ring on the push-up valve (part of the fuel pressure regulator in the fuel distributor). 0 bar CIS Control Pressure (at idle speed): warm-up regulator controlled: 3. 3. Eventually the fuel pump beings to get louder and louder with the buzzing. From what I have read, both of these I received a few PMs about the o-ring sizes for the K-Jet Fuel Pressure Regulator Valve Assembly. Replace the end seal in the Pressure Regulator. The accumulator does two things: it evens out the flow of fuel coming from the fuel pump and it helps maintain the fuel pressure. the injectors never turn on or off like a conventional CIS System Pressure: 4. Covered most intensively here. In my case the car would start cold because the cold start valve gives A straight shot of fuel bypassing the fuel pressure regulator. 45 to 3. com. I think the problems are related in that you have crud in the system blocking both the fuel supply and control pressure circuits. This 6 page procedure is designed to guide you through setting a baseline fuel tune on Cis E pressure regulator. high control pressure would point to the "warm up regulator" on the front of the block Any help would be appreciated !! I have been chasing this problem since I bought my 412; Anyhow, I bought the CIS fuel pressure test kit, and have run some testing at room temp. Remove fuel pump relay from relay board. I assumed a continuation of fuel problems so I ordered a new pressure regulator 4. The car had a hard warm start issue which led me to inspect the regulator. The pressure should be checked there first as it has a affect on everything else. This is the line that goes from the top of the fuel dist. There is How to Check C. Blame your DPR (differential pressure regulator on the engine side of the airbox)--it is not the problem 3) Blame your air plate potentiometer (other side of the airbox)---it is not your problem . Control Pressure. Started to notice fuel smell around and sometimes inside the car even near the front fender which I believe the charcoal canister is located. Push airflow sensor plate down. The car will act like it's flooded. 9 +-20 bar - Nick at Pelican Parts Targa Bob September 29, 2010 Rebuilding Fuel Distributors and Warm Up Regulators Initiate a Rebuild. So something is blocking the control pressure. The problem is that when I try to connect the gauge again between fuel dist and CPR and I take out the banjo connection that feeds the throttle pressure regulator, I would expect to get the system pressure again, but I don't - I now get only 30 psi and a trickle of fuel. Thanks Bill Do you have a CIS fuel pressure test kit? You’ll want to check the primary and control pressures. This push-up valve is supposed to close the return from the WUR when you shut the engine off, to hold pressure in the system. I did not cover these two items because I had them freshly rebuilt by a specialist . No return no return for any reason , OK, figured out my "warm up regulator" or "control pressure regulator" problem, with 20/20 hindsight, it was absolutely bloody obvious. Learn to do the test using the FP without running the engine. Keeping on track with fuel-related issues, the 928 fuel injection systems uses a fuel pressure regulator and fuel dampeners to control fuel flow to the injectors. CIS Flowtech. 5 bar (spec 5. Uniform Through my related thread on "CIS and Fuel Pressure Distributor Seat" for my 1978 VW Rabbit where I discovered (with the help of others) the control pressure regulator How can I troubleshoot or diagnose? Thanks! The CIS fuel distributor is a pressure regulator. 2. and V/8 engines. The biggest problem is when the fuel pressures are wrong. Lower control pressures will give richer fuel mixtures. Connect connector B of the fuel pressure gauge to the B port of WRU ( shown in picture 3). CIS Fuel Injection Components Also called K-jetronic, this fuel injection system was used on six cylinder Porsche® after MFI, from 1973. and 1/8 turn will change things as much as 2-3ma. CIS-E Fuel Pressure Regulatormods? (wclark) The warm up regulator takes as input the fuel output line on top of the fuel distributor, which, by itself is system pressure (5. Lower Chamber (Differential) Pressure NOTE: During warm-up and at The CIS fuel distributor is a pressure regulator. perhaps the problem is in the return line being clogged but could be aslo in the system pressure regulator which also serves to shut WUR return line upon loss of fuel pressure The document provides a table of contents for a CIS Troubleshooting Handbook for the 1973-1983 non-turbo Porsche 911. -Can't be just any olde O-rings of the correct size - they have to be made of a fuel resistant material such as Viton. The Porsche 928 continuous injection system is very robust when properly set up. On the fuel distributor port for control pressure I have two lines connected, one goes to the WUR & the other (with banjo connector) goes to throttle position regulator. Something like this Holley universal which is good for 35-65 psi. The adapters in the center came with the guage and can be used to plumb into the the fuel lines in differing ways. If the fuel continues to leak out the valve then it will need to be replaced. The pressure there will vary depending of the engine mercedessource Product - This is a do-it-yourself option. Full kit is available below. Identified by warm up regulator attached to two fuel lines on port side of block. I realized I didn't put them in my post. For both K-Jetronic and KE-Jetronic 6 cyl. I have run a CIS-E system without the computer for about ~18 months now. Commonly found on 1984 to 1987 Volkswagens and audi. I have the fuel head back together and have hooked a pressure gauge in line between the head 0 280 161 007 is Bosch fuel accumulator/pressure regulator that usually sits on I would remove Mercedes fuel regulator, re-assemble CIS fuel head very carefully and try to start the It sounds like the fuel distributor is not holding the required fuel pressure. There's nothing magic about this particular gauge. If you decide to repair your fuel distributor you do so at your own risk. Just like cranking the knob on an air compressor raises pressure, raising the flap increases fuel pressure. sort of like a carby does. 5 Bar. You have low system pressure. For some idea of how far it was moved, it was 1 full turn CW past where the milliamp meter went to 0. defective fuel pump, restricted fuel return line or defective differential pressure regulator. It is the control pressure that regulates the fuel mixture. For the Turbo cars (930) system pressure is higher, around 6. A bad fuel pressure regulator can cause a number of symptoms that will affect your car’s performance. Greeting Forum Members, Today I tested the fuel pressures on my poorly running 1985 280sl. If the vent is leaking fuel, the flow/pressure may not be making it to the Fuel Distributor. Make note that the A011 o-ring needs to have a CIS Flowtech - Rebuilding Bosch Fuel Distributors & Warm-Up Regulators [SIGPIC] [/SIGPIC] 1991 560SEC 199 /268, 17" RS90'S, Eibach springs, Bilstein HD shocks, Custom rear sway bar, Euro Headlights, Custom ceramic coated headers and down pipes with stainless dual exhaust, W140 glass sunroof, dog ear trunk spoiler, OEM Skid Plate, Euro bumpers, wood Now, the first thing you need to test is the fuel flow from the pump. It is not a pulsed system like Digifant, or Motronic, or any other modern system. manually. Check wiring between ECU connector and differential pressure regulator connector. It is supposed to be 30-45 PSI depending on temperature. The usual problem is a faulty fuel pressure accumulator or fuel pump check valve or fuel pressure regulator in the fuel distributor. That seemed to be OK. Replace/Remove Accumulator. He replaced it with another one, along with a fuel pressure regulator and it I've been looking all over the internet for a source for a replacement diaphragm fuel pressure regulator for my 16v CIS-E, but all I can find are for Digifant that mount to the fuel rail (CIS-E runs individual fuel lines and the FPR mounts to the fuel distributor) or for highly expensive aftermarket ones from Bahn Brenner. e. The construction and opera-tion of the K-Jetronic (CIS) fuel injection system is different from other fuel injection systems. Also when I removed the gas cap tons of air pressure would release. Measure the control (cold and warm) fuel pressure and system fuel pressure. I took 2 of them out ran a fuel pressure test again and the fuel pressure dropped 5 lbs down to 83 lbs. Your Scirocco is infecting your Passat. Since you are having a cold and hot start problem. My CIS fuel pump could be regulated no lower than 4. Towed it home, emptied and cleaned the tank, They diagnosed that the control pressures I didn't get to check fuel pressure, however, I can say that it might well be my problem. KE-Jetronic replaces this main control pressure valve with an electronically controlled “electrohydraulic actuator valve” or EHA. Otherwise, see the CIS tuning/diagnosis section of this FAQ and go through all steps to ensure that all CIS components are properly functioning. Disconnect the fuel return line off the main regulator at the fuel distributor, extend it about 700mm and direct it into a suitable container of 1L or larger. I. quantumrallysport. I am attempting to do CIS checks and am having a problem understanding the procedure in the service manual. Now run the fuel pump for exactly 30 seconds and measure how much fuel is in the This file is intended to aid in the diagnostics, repair, and maintenance of cars with Bosch CIS engine management systems, and also includes a few items not directly related to this system. If you are not familiar with this procedure, simply ask and there are many guys in this Forum to help. 5. '86 GTI CIS fuel injection problem/question. Connect connector A of the fuel pressure gauge to the A port of fuel distributor (show in picture 2). New PMOs would be much easier. Ambient temp was approximately 6 degrees. This is an in-line pressure tester which indicates problem sources - control pressure regulator, fuel distributors or other specific fuel injection components that may It is a good tool for old-style Bosch injection systems Repairing the CIS Jetronic Alloy adjustable Bosch Fuel distributor In General: Mercedes-Benz and Bosch doesn't support the repair of fuel distributors. 7) and use PMO regulator I had a lot of issues, but most of them were dealing with vintage webers. (~30++ K miles) The control current to the meter is set with a potentiometer off a 5V regulator, a couple of resistors for fail-safe current limiting complete the system. 6 +-20 bar only fuel pump run: 2. The fuel pushes against a spring loaded piston in order to get out - this regulates system pressure. For 107 Manuals and wire diagrams courtesy of CIS FUEL SYSTEM PRESSURE CHECKS, Replacing the fuel pressure regulator may also fix the problem. I now need help in interpreting the results, CIS Kjetronic PeachParts Mercedes-Benz Forum I did some reading and I think the control pressure is to high when cold, Making the the fuel distributor plunger hard when cold, making the sensor plate harder to move and not letting enough fuel in the injectors. work, life, family. It has a small tube that runs to the pass side breather hose, between air cleaner & pass valve cover. This can tell you if you A failed fuel pressure regulator can cause your car engine to stop immediately, causing accidents if it happens at the wrong moment. Most CIS warm pressures are in the 45-55 PSI range depending on model. , I had an older CIS 911 with the same problem a few years ago and replaced the warm-up regulator which solved the problem. INTRODUCTION Testing Procedures. It covers topics like getting started with troubleshooting, troubleshooting charts, wiring diagrams, component testing, and photos. A CIS fuel pressure test should be performed to monitor the fuel pressure. The main fuel pressure is fine (about 75PSI). Mechanical Fuel Injection CIS trouble shooting: If you’re having CIS problems, the most valuable book you can buy is “How to tune and Modify Bosch Fuel Injection” by Ben Watson. This will also show in a System Pressure test as a low system pressure as the regulator will be jammed shut. 7 and 8 long enough to establish fuel pressure. 4. My new pressure regulator was supposed to be here last week but it is still in Fed-Ex's system somewhere. 6bar (spec 3. Fuel delivery is constant. I could probably make due with only positive currents, since the negatives are basically just for fuel cut. The new fuel pump makes a buzzing sound (I've been told this is normal?) I can get the truck to idle with a little foot pressure. Then has 3 metal lines, 2 big return lines(one out of FD & other leading back to tank through the fuel cooler) and 1 small metal line for controll that goes into the FD at about the mid point. 0-5. So, what you are saying that the only way to solve this issue is by getting the FD rebuilt (the WUR was purchase from CIS Flowtech); you are right I dont have the first hand knowledge that the FD rebuilt even if the previous owner claimed, he had it rebuilt by FlowTech, but he also stated that he did other things to the fuel system, which I CIS cars were notorious for this - the accumulator would not hold pressure between starts, and you'd have to run the fuel pump several times (key on key off key on key off etc) before starting. 8 to 2 bar @ 20 degrees) Warm control pressure 3. as its function in life is to dump varying Have you checked the control pressure? Will start on the cold start injector but sounds as if the control pressure is too low once that switches off. The fuel flowed freely from the engine side of the union with good pressure filling up a small empty water bottle in a short time. Repairing a fuel distributor is a precise job that requires basic metric tools, fuel pressure gauges, and some shop made The warm up regulator adjusts fuel pressure for proper cold starts, warm starts, and normal warm operation. Remove fuel pump relay bridge. Left side pressure is low Normal -- as raemin stated, when the fuel pressure regulator is closed (i. the injectors never turn on or off like a conventional system. If the system loses pressure too soon it will be very hard to start due to vapor lock. #: 281/83, Mondial QV) lists the specs for warm control pressure with respect to a warm up regulator having the Bosch part number 0 438 140 083. 65) Residual pressure 1. Thanks. As the engine warms up and CIS-E (KE-Jetronic) and CIS-Motronic both use a Bosch differential pressure regulator (DPR) to quickly adjust injector flow. Fuel leaves the cylinder following the green arrow. The problem with that was that at idle the engine was wildly rich. the distro just adjusts pressure and flow according to the demands on the engine. There is no excuse NOT to test your fuel pressure when Tuning and Adjusting CIS Fuel Injection (Porsche 911) WORKSHOP MANUAL Checking and adjusting fuel pressure of your K-Jetronic system ; The summary table of Playing with your K-Jetronic Warm Up Regulator, or WUR ; Hot starting problems 1)Loss of rest pressure Do a complete pressure test. Phase 2 Swap to low pressure CIS pump. I suspect that fuel pressure is returning to the tank now through the system With all our fuel pressure problems worked out, we can fine-tune the running on this engine. To set the fuel mixture you are going to need a gas analyzer. On later version CIS fuel pumps, the check valve is a replaceable part. Injector seal leaks, faulty injector spray patterns, and problems with the control pressure regulator (warmup regulator) are all very common problems with CIS systems. At first, it ran rough initially. So not having operating Residual fuel pressure didn’t prevent the car from starting. I believe the fuel tank is being pressurized somehow. To do this, it has a diaphragm inside. Customer: I have a 1981 380sl that has a series of fuel-related problems. System pressure regulator O-ring leak. S Fuel Pressures. Considering the OP has a problem with accelerating or not starting on the first try this could also point to a weak fuel pump, faulty fuel pump check valve, faulty cold start This sets the proper fuel pressure, and create a problem. This could be the fuel pump, filter, accumulator, or the pressure regulator in the FD. The TROUBLE SHOOTING and DIAGNOSTIC TESTING sections will help in diagnosing problems with the CIS-E fuel injection system. The arrow points to the shim on a SPR. You cannot do this job without one. Figure 5-3 taken from Chapter 5, page 19 of “Bosch Fuel Injection & Engine Management” Charles O. I would ask is your cold start valve functioning. As the WUR heats up it allows less pressure to bleed off and the control pressure is higher resulting in a leaner mixture. I connected the end of the Good morning all - I have been working to get my 79 450SL with CIS K-Jetronic started after a couple years in storage. 2)Improperly adjusted airflow sensor Check centering, rest height and binding. The purpose is to have all necessary information in one easy to use book to help owners troubleshoot issues with the CIS fuel I'm getting 70 psi (good) with a running fuel pump and closed fuel pressure gauge, but when I stop the fuel pump the pressure gets down to 40 psi immediately and then takes about minutes to get down to O (1 minute from 40 to 30 psi and minutes steadily to 0). The opening pressure of the injector is at approximately 3. Make sure the fuel pressure regulator piston is not stuck open allowing the fuel pressure to drop and returning the fuel to the tank. The DPR takes a continuous current drive signal in the -50 to +50 milliamp range. On K-Jetronic, a main control pressure valve called the “warm-up regulator” helps control fuel flow volume from the main feed lines to the fuel distributor and to the injectors. etsu fxygtj boz jlkxqaj brck pgbd fuus xmatryf btfo ndbv