# power loss/stalling and hot start issues



## redone17 (Aug 17, 2011)

I was hoping I could get some help diagnosing some issues I'm having lately. If read through the Bentley and I have some tests to run - but I don't have a fuel pressure tester and was hoping I could eliminate some possible problems and narrow down my tests. I'd prefer not to throw parts at the problem and narrow it down to a few possibilities. 

I have a bit of a Frankenstein setup in my 88 CIS-E Fox Wagon. It still has a stock bottom end. The intake/auxiliary air regulator are from a Digifant Fox, Corrado G60 (MK2) Counterflow Big Valve Cylinder Head: Ported/Polished - new valves, seals, lifters
w/ AutoTech 270 Hydrolift Cam, Neuspeed Adjustable Cam Sprocket, G60 valve cover, G60 throttle body/MK2 16v adapter/Scirocco 16v bracket and cable. All new injectors, seals, spark plugs, etc were used. 

That was all installed about 18 months ago. I didn't drive it much for the first year - but have been driving it daily 20 mile round trip to the train since June 1. I removed the idle boost valve and plugged all the open vacuum ports until this weekend when I reinstalled everything. Thinking that was my main idle issue. It didn't seem to do much. I can't find any vacuum leaks. Here's the run down:

Cold start - no problem every time. Once the fuel stops flowing through CSV I need to put my foot on the gas otherwise it stalls. Even the slightest pressure bringing the RPM to 1500 does the trick. I drive 10 miles to the train every morning. Warming up it sputters a little bit. Once cruising - pick up is adequate and I can get to where I'm going. The second I lay on the clutch and let off the gas the engine shuts down unless I keep some pressure on the gas. I end up popping the clutch if I still have momentum approaching a stop sign/light - then keep it in neutral with my foot on gas until it's go time. 

I'm also having hot start issues. Once it's fully warmed up - if it stalls it won't crank over. Thankfully there are enough hills on my way too and from the station. Not very safe - I know. Luckily small town and I'll get to fixing it shortly - hopefully with some help on here. 

Appreciate any input from some of you that are more experienced. 

Ideas: auxiliary air regulator is stuck, fuel accumulator is spent, one of the fuel pumps isn't working to it's potential. 

CP


----------



## nbvwfan (Aug 15, 2007)

This is tell-tale signs of a control plunger stop depth needing adjustment, especially seeing your engine is breathing more air and mot too dissimilar to my initial woes when I supercharged.

Being CIS-E the magic number is 19mm. After you get the depth set, you move to the mixture screw to set the pivot depth.
What you are aiming for is just about .2mm of sensor plate freeplay when the system is pressurized and the at rest sensor plate at nickel thickness.

My little brothers 86 GTI had a lot of what you describe and ~10 minutes setting the plunger just a bit and then the mixture screw got it working great.
If you search my posts I have the exact procedure written out a few times on the threads.
PM me if you get confused.
Good luck
:thumbup:


----------



## redone17 (Aug 17, 2011)

Thanks for that info/diagnosis! That makes a lot of sense - and after reading that section of the Bentley - I have to give that a whirl. I would be PSYCHED if it were really that simple and if I don't have to sink $$$ into it right now.

I will report back.

:beer:


----------



## nbvwfan (Aug 15, 2007)

redone17 said:


> Thanks for that info/diagnosis! That makes a lot of sense - and after reading that section of the Bentley - I have to give that a whirl. I would be PSYCHED if it were really that simple and if I don't have to sink $$$ into it right now.
> 
> I will report back.
> 
> :beer:


No problem,
I hope it helps.
From what I have learned the control plunger stop depth is often overlooked on the troubleshooting of CIS.
Though from what little I understand of the "floating body principle". The CIS meter is designed around a very specific flowrate, and any changes to volumetric flow or "work" the engine exhibits will effect the fine operation of the stop depth and sensor plate. By adjusting it you can effectively change the "zero" to better suit the new draw.

I found this on my application after a lot of trial and error. The main challenge was countering the stronger pumping action the G Lader made on the sensor plate.
In short I ended up doing the opposite of what I thought would work (lowered the plunger stop depth). But afterwards I then adjusted the mixture screw to effect the other "zero" which was the pivot bearing. The key element being maintaining the ~.2mm freeplay once I had the depth about where idle was fair and A/F was ideal.

This is a lot more information than you need to know, I assume, but more is better than none.

for your application,and by the sounds of it, you need to adjust the stop depth out about 1/8 to 1/4 turn CCW then correspondingly lean the mixture screw probably close to 1/2 turn. Then with the pump pressurized check the sensor plate freeplay is there so as to avoid a rich condition.
This is a guess, but I bet close to what you need short of maybe first verifying that you have 19mm which I bet is just a bit short.

On my brothers it was a matter of about 1/8 CCW on the plunger stop depth, and then richening the mixture about 1/2 turn CW (by ear and feel, his was lean), and last adjusting the idle air screw to bring it down to ~950 RPM.

Good luck, just don't make too many adjustments at one time.


----------



## nbvwfan (Aug 15, 2007)

Two other things to add.
You mentioned having an auxiliary air regulator.
I am not familiar with that being in CIS-E. Do you mean the ISV. Or can you post a picture of that?

Second, the first thing I would look at is the sensor plate rest position (nickel thickness) and pressurized system sensor plate freeplay (about .2mm or about 1/2 mm under the first cone transition).
If it is loose, you can effect it by turning the mixture screw CW. That is one of the first things I have done to dial in a rough idle.
It just might be a little off where it needs to be.


----------



## redone17 (Aug 17, 2011)

I think once I open it up it will all make a lot more sense. I may wake up early tomorrow just to pop it open and see if anything looks awry. 

As for the AAR - it's the drum looking thing on the right with the vac port on it:











Come to think of it my PCV valve dumps right into the back of my air filter box w/o a filter of it's own (using the G60 VC cover I had to jimmy something up).


----------



## redone17 (Aug 17, 2011)

I thought I would mention - these symptoms got worse. At first idle was rough - but it stabilized once warmed up.


----------



## nbvwfan (Aug 15, 2007)

redone17 said:


> I thought I would mention - these symptoms got worse. At first idle was rough - but it stabilized once warmed up.


Saw the picture this morning and was thinking some on the drive to work.
Looks like you have CIS-L
L being Lambda Controlled CIS.
The AAR does a lot to effect this system.
Now that I have seen the set up, I would first recommend you try and clean the AAR as my guess is it is sticky and allowing "un-metered" air into your system which is only compensated by opening the throttle and thereby lifting the sensor plate and adding more fuel.
These are known to stick, and I have heard some say WD40 while energizing it on 12V helps free them up.
Do a search on it though as my experience with CIS-L is a bit more limited.
All the other stuff is relevant but now the symptoms point to the AAR.
Good luck.


----------



## redone17 (Aug 17, 2011)

that was just a random pic I took off the web for an example.

1988 Fox is definitely CIS-E.


----------



## ChristopherF (Aug 26, 2010)

Redone,

1. I've wondered for a while if it's red-one or re-done. 

2. You didn't trust your buds on the Fox forum to help with your problem?

I had similar, overlapping problems with my Fox. My Fox would start OK most time when cold but was a pain when hot. The car would crank OK with one turn of the key but wouldn't crank the next. I traced this problem to the two bolts that hold the starter together were loose. I've had other starter problems with the starter itself loose on the bell housing and the power cable loose on the starter. With the bolts tightened up, the car cranks like it doesn't have spark plugs in it.

The other problem was the main fuel pump going bad. The car had a replacement fits-all pump on it and I cannabalized a Bosch pump off my parts car. Problem solved.

Chris F


----------



## redone17 (Aug 17, 2011)

it's re-done - like the opposite of undone. haha. but I have a red beard and generally could be considered the red one too 

I've been wondering if it's the fuel pump or related parts, but I don't have a way to test the fuel pressure.

I am going to seek out a CIS/8V mechanic in my area. I wish I could say I have the skills - but I would rather trust a professional at this point.

Good news is I am getting my '89 Coupe back in a few weeks - so that can be my daily and the wagon can get pulled apart and start on some of the body work...if I ever have the time. At least it will be in the garage and not rusting away further...


----------

