# *CAR WON'T START & RUN / CIS Bosch K Jetronic Problems* - 1982 VW Rabbit 1.7L I4 Gas Engine



## arthix0 (Sep 19, 2020)

Hey everyone, after the last 2 months of trying to get my 1982 VW Rabbit 1.7L I4 gas engine to start and run, I'm at my wits end and am therefore writing this here desperate plea at help. I'm new to these forums btw, so I apologize in advance if I overlook some of the etiquette / formalities that go with these forums. 

I have a 1982 VW Vanagon (diesel model) with a VW Rabbit engine swapped into it. I had the rabbit engine running on several occasions, but it always had problems starting up. Now, it won't start and run at all anymore. Here's a list of stuff that I checked / replaced:

+ Checked fuel injectors. One (1st one) was bent and broken and another one (4th) was clogged. Replaced both and cleaned all of them with pressurized carburetor cleaner. They all show a nice mist conical spray pattern now. (Btw, how does a mechanical injector get bent and cracked like that?)

+ Checked fuel injector seats. 2nd one was cracked at the O ring seal of the fuel injector. Replaced all 4 injector seats and all 4 O rings on the injectors. (When I was removing the injector seats, I noticed that they all had what looked like white thread tape on the threading.. Is there supposed to be some sort of thread sealant here, or is it fine to just tighten them in without any?)

+ Replaced fuel distributor and air metering unit, because the old fuel distributor was leaking out from the sides and fuel / air mixture screw has been adjusted with the allen key left in there for a while. Didn't want to take a chance to try and open up the fuel distributor and replace all seals, because I heard that's a nightmare. Fuel distributor seems to work fine now. Metering plate is nice and clean on both sides and still looks like it has the original adjustment. I even have the cap on the fuel / air mixture screw (seems rare!), so I'm guessing that hasn't been adjusted much either.

+ Pulled a wiring diagram for a 1982 VW Rabbit engine and checked all the wiring. Fuel pump relay was replaced with one that only has 4 terminals (1.Ground, 2.Power from Battery, 3. Power to Fuel Pump, 4. Power from Ignition / Signal from Ignition Coil). The original one should have 5 terminals and have "Power from Ignition" and "Signal from Ignition Coil" on 2 separate terminals. Is mine fine the way it is? The motor did start and run on several occasions, so maybe that's not the issue? I wired up the auxiliary air valve, control pressure regulator, and cold start valve / thermo time switch. Tested cold start valve. Works fine with 9.5V+ of power, but doesn't work in combination with the thermo time switch. The red / black (hot wire) gets voltage fine from the ignition switch (both at the TTS connector and the CSV connector) and the ground of the TTS seems fine when I connect a multimeter to it and battery power. Just can't get the CSV to work when it's connected to the TTS, it goes from ca. 2V to 0V in 6/7/8 secs. Should go from like 9-10V to 0V in that time... Now, I just jumped the ground at the TTS connector and the CSV works fine when I crank. Maybe the TTS is shot?

+ Changed fuel filter. Connected a fuel pressure gauge between top of fuel distributor and control pressure regulator. Followed these steps (link blocked...) to check system line control pressure with the fuel pump relay out and jumper wire in. 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 90 minutes to get down to O (1 minute from 40 to 30 psi and like 89 minutes steadily to 0). Can't check cold engine / warm engine pressure without a running engine either, or else I'd have those readings as well..

+ Replaced several hoses (PCV) and checked on other plugged horses for air leaks. Can't seem to find any air leaks, but I can't get the engine running either so that I can spray starting fluid mist around the system and search for them either..

+ Replaced valve cover gasket.

+ Checked ignition coil. Exactly what the manufacture had specs at it for. Checked spark plugs. They're black / dry / carbon. (Means it's running rich, probably because of the bad air / fuel mixture on the old metering unit and all the fuel that was being thrown into the engine). Cleaned them and checked for spark. All shoot out spark, not that super strong and blue, but still sparking. Engine was running on some occasions, so maybe fine?

+ Taken off my throttle body and cleaned it (cleaned as far as I could reach inside air intake as well). When holding the throttle body against the sunlight, I noticed that the flap doesn't shut all the way tight because of the adjustment screw. Is there supposed to be a tiny mm-like gap? Why would there be that adjustment? Also, the way that I understand how the air metering unit and fuel distributor work is that the vacuum generated by the pistons lift up the air flow plate (therefore raising the plunger in the fuel distributor) and pushing fuel through the injectors. Why are all injectors getting fuel at the same time? (seems weird?) And is there an idle position that the plate is supposed to be in, so that it gets fuel after you crank the engine (cold start pushes fuel to start) and then keeps giving it enough fuel to idle? Maybe my engine is just not getting any fuel that it needs to start idling? Or is the vacuum generated by the engine supposed to immediately pull up on the air flow plate when you crank it? Since, my cold start valve works now being jumped, the engine tries to start but then feels like it doesn't have enough fuel to keep going. I'm thinking this has something to do with this whole air flow plate / fuel distributor / fuel pressure.. Also, when I crank, the fuel pump isn't going. That's how it should be, right? (because cold start supplies the little fuel to start with and then key returns to ignition on position and fuel pump goes again with a raised air flow plate / fuel distributor spitting fuel through injectors).

+ Also, I don't have an oxygen sensor and my frequency valve is disconnected (doesn't even have a connector anywhere for it). Will the car still run without these? It should, right? I don't even know where the oxygen sensor is supposed to be. Maybe that's also causing a major air leak?

I also don't have a hot start pulse relay anywhere for the CSV / TTS. It should run without one?

I really do apologize for this long post and all the info., but if you can't already tell, it's been an extremely frustrating last 2 months and I still can't get this engine to run normally.. Even after replacing part after part, it's somehow not getting anywhere. I did a compression test (around 107 on inner 2 cylinder and 112 psi on outer 2 cylinders). Hoping that that compression gets better with a running engine when all the carbon and crap gets cleaned out of the cylinders. Probably bad compression because it's been sitting for a long time and hasn't been running. A couple weeks ago, when I had it running for a good 10 minutes, I had a family friend over that was messing with the distributor (rotating it) and trying to change the firing order of the spark plugs (to get it to run smoother). Now it's at (clockwise): 1 Top Right, 3 Bottom Right, 4 Bottom Left, 2 Top Left. I don't know if messing with this distributor etc. is what made it not run, but I got it to run for very briefly (1 minute) recently, before it suffocated and died, so maybe it's set okay? Maybe it's just the air flow meter / fuel distributor adjustment that's missing? or some massive air leaks somewhere? I'll post a pic. here of my engine (and some of my dirty throttle body the way its positioned on the air intake; if you zoom in you can the see the little gap to the right of the right flap). Links at the bottom. If you want me to take pics of anything specific or a video, tell me and I'll post as much documentation of it as I can. Sorry again for the long post and hoping that some good soul out there can help me get this thing to run! Really do appreciate any help!

Thank you!

Pictures:
(Can't post links here because I'm new to the forum... )


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## MacGruber (Aug 20, 2010)

Bentley Manual has Troubleshooting Table - NO START for instance.

Fuel pump relay: never mind that, just JUMP the relay as you must have to check fuel pressure. 
I have driven my Scirocco with jumpered Fuel Pump relay, my own starter switch and IGN (15) toggle switch 
because replacing the Ignition switch sometimes can't be done immediately.

Cold Start Valve is only needed when it is cold. I forgot to reconnect the plug for a few days and drove around OK.


> > Also, I don't have an oxygen sensor and my frequency valve is disconnected (doesn't even have a connector anywhere for it). Will the car still run without these? It should, right? I don't even know where the oxygen sensor is supposed to be. Maybe that's also causing a major air leak?
> 
> 
> The ECU takes into account a defective O2 Sensor and goes to Default mode without a signal. To operate the Frequency Valve. That is all it does.
> ...


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## 79MK1Scirocco (Aug 23, 2011)

Maybe Im late, 
Have you gone though and checked timing on everything? it is pretty easy to get you ignition timing off by 180°, or there is always a possibility that you cam jumped. 
See if you can get it to run with starting fluid, that wold definitely tell you if this is a fuel issue or ignition issue.

If that all checks out it sounds like you have gone though the CIS system pretty thoroughly, although I dont think that I saw that you checked the WUR.
That controls the system pressure and could be out of adjustment causing low fuel pressure at the injectors. 




+ Taken off my throttle body and cleaned it (cleaned as far as I could reach inside air intake as well). When holding the throttle body against the sunlight, I noticed that the flap doesn't shut all the way tight because of the adjustment screw. Is there supposed to be a tiny mm-like gap? Why would there be that adjustment? Also, the way that I understand how the air metering unit and fuel distributor work is that the vacuum generated by the pistons lift up the air flow plate (therefore raising the plunger in the fuel distributor) and pushing fuel through the injectors. Why are all injectors getting fuel at the same time? (seems weird?) And is there an idle position that the plate is supposed to be in, so that it gets fuel after you crank the engine (cold start pushes fuel to start) and then keeps giving it enough fuel to idle? Maybe my engine is just not getting any fuel that it needs to start idling? Or is the vacuum generated by the engine supposed to immediately pull up on the air flow plate when you crank it? Since, my cold start valve works now being jumped, the engine tries to start but then feels like it doesn't have enough fuel to keep going. I'm thinking this has something to do with this whole air flow plate / fuel distributor / fuel pressure.. Also, when I crank, the fuel pump isn't going. That's how it should be, right? (because cold start supplies the little fuel to start with and then key returns to ignition on position and fuel pump goes again with a raised air flow plate / fuel distributor spitting fuel through injectors).

Sorry, I just read this portion,
Yes your fuel pump should run while the car is cranking and even for a moment after your turn off the ignition. Jump your relay while you crank to see if you get something to happen. Maybe you just cant hear it over all of that cussing and cranking?

However,
It sounds like the car wants to run after a long time of cranking, I think that you are getting some fuel
I would definitely investigate your system pressure AND
Pull the fuel distributor off of the air meter, look at the plunger that rides on the air meters arm that. Make sure that little plunger is moving free, it should fall right out. if it is gummed up in there soak the entire fuel distributor in a bucket of carb cleaner over night. 
If that plunger is not dropping the fuel distributor is never going to deliver the fuel you need. If it is always stuck up it your car is going to starve for fuel. 

Another check you can run is to remove your injectors and put them into jars, then jump your fuel pump. lift the airflow meter with a magnet, as you lift the injectors should spray fuel (and an even amount)

Yes all four inheritors squirt at the back of the intake valves, just like a carburetor, but a little more precise.
Yes the motor creates enough vacuum when cranking to lift that air meter, cold start valve helps with that precess
Yes there should be a gap on the throttle body plate. 

Good luck, it sounds like your really close to finding your problem!


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## DbilasTDI (Nov 5, 2017)

is the tank full of old gas? they dont like shi gas


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