# Turbo CIS flake



## CALLAWAY TURBO (Aug 27, 2005)

So, turbo CIS with a fifth injector, ocassionally when I give it boost it seems as if something "latches" up.

I have a wideband installed and when it flakes the A/F goes to around 19 and pretty much stays there.
Engine is running crappy of course. 
No amount of revving or engine load gets it out of this mode.
It still drives.

If I shut the engine off and start it right back up it goes back to normal.

Thoughts:

If the plunger was stuck I would think it would be running rich.
Presumably under boost the flap opens up quite a bit -OR- the fuel pressure get whacked
by the fuel going to the fifth injector.


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## Butcher (Jan 31, 2001)

Runs at 19 all the time? Only at full throttle?

I would look at some air leaks [before turbo].


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## CALLAWAY TURBO (Aug 27, 2005)

No it only goes to 19 when it flakes out otherwise it runs fine (13.3 at idle and up to 15 tooling around). 
It flakes out (sometimes) after giving it some boost. 

When I turn off the engine and restart it will recover.


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## kwak (Apr 7, 2005)

I am wondering how to distinguish between an electrical problem and a mechanical problem. Is your CIS system off a turbo car or was the turbo added to a non-turbo CIS system? What controls the 5th injector? Is it on full time or only on under boost?

If you have a 5th injector only on under boost then I would look at fuel pressure. That is the only thing I can think of which might "reset" from being too lean back to being in the right range -- fuel pumps, fuel pressure regulator, etc.

For reference on a CIS-E system idle will be around 14.7 and so will normal driving around. A rich condition only happens under WOT (and warmup).


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## Butcher (Jan 31, 2001)

I'm still confused. When it flakes out, is it at idle? Part throttle? Full throttle? What are you doing when it starts to act up? I do understand the problem goes away when you cycle the key.

As with all diagnosis, you got to start with the basics and have the tools to make some tests. Or you can do it the Vortex way and throw parts at it until you run out of money or patience. Watching the fuel pressure is what I would do. Is it CIS with Lambda? If so, I would watch the duty cycle too as well as the O2 sensor signal [not the wide band sensor unless the wide band is controlling the lambda circuit].


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## CALLAWAY TURBO (Aug 27, 2005)

One more time ...

Give it a little boost 5-8 psi ... THEN SOMETIMES ... after letting up on the accelerator ... the A/F goes to 19 and STAYS THERE.
Car is sluggish. Rev the engine, stays sluggish, A/F is around 19. Restart, it goes away.


Ok, so ... if the plunger was sticking I would assume it can't make it go lean.

If something happened to the plate, figure it would kill the car flat out. 


Oh, it CIS lambda.


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## Butcher (Jan 31, 2001)

Thanks for the added information. I have yet to run into a sticking plunger and yes, if it was, I would suspect it would be running rich since the plunger would not be hitting the plate. The issue you have is a lack of fuel or an abundance of unmetered air.

Again, testing the fuel pressures is where I would start. I would also want to know what the frequency valve was reading. I would also suspect the intake hose from the air flow housing to the turbo could be loose. Smoke testing the intake would be ideal if you have that tool in your arsenal.


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## CALLAWAY TURBO (Aug 27, 2005)

I have buzzed out the car quite a bit leading up to this.
Basically I'm tuning a new AIC controller since the Microfueler is shot.

Its the odd "latch up" aspect of this that has me puzzled. 
I suspect it has something to do with the plate hitting its full extension somewhat violently. 

The other thing I wonder about is the 5th injector is fed off of the return line.
I wonder if the dizzy expects some back pressure as in if the 5th injector is draining off a lot of fuel 
would that screw things up? Some sort of hydrostatic lock-up in the dizzy. 


I did have to clean the plunger a while back, was gunked up.


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## Butcher (Jan 31, 2001)

Simple, disconnect the stuff you added and see if the problem reoccurs. 

I do not think the injector should be hooked up to the return line since that line should not have a lot of pressure. I would make certain you're correct in what line it's attached to or hook it up to the feed line.

Again, fuel pressures and unmetered air is where I would start at.


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## vwturbofamily (Oct 19, 2016)

i run my turbo cis-e all day long at 15psi and at the track i run 30psi. now i remember a while back i had a simalar issue. what i figured out i had the flap on the cis-e adjusted up to hi so when i whent onto boost it was just garbage try making a few adjustments on the flap


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## CALLAWAY TURBO (Aug 27, 2005)

Wound up replacing the Dizzy and the WUR.
Not sure which was the source of the problem.

I could swear I heard a hiss from the WUR while testing with the fuel pump relay jumped. 
Didn't smell gas though. 

Anyway that seems to have done it. Running rich to 10 psi.


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