Car won't stay running after new build

[90TSI717]

Hey guys,

I'm currently having a problem starting/stay running after my rebuild. The car (90 TSI) is running pig rich (just by the way the exhaust smells) and I have tried just about everything short of going to a shop. The rebuild consists stock bottom end with new rings; redone head with new valves, valve seals, springs, lifters, and delta 272/272 cams. All gaskets are new. The only way we can "keep it running" is by keeping a foot on the throttle pedal and increasing the RPMs. It will idle for a few seconds or not at all without the assistance. Before when we first starting getting this going hoping for a good start up it had idle surge after a few failed attempts and only when it was warmed up.

Had dacowgod remote link to the ECU and tuning was apparently NOT the issue.

The TPS and IAC are working are log-able via Link. The TPS is set correctly and also the IAC was tested for bad coils and for proper in/out operation when the ignition is turned on.

Boost leak tested up to about 15 psi or so and while it does drain out, there are no visual leaks using soapy water. Found out the PCV is bad but with it blocked off you could still hear air sounds from the oil cap (removed). Plugs when removed for a compression test smelled like gas and the #2 plug was much darker than the rest.

The plugs go from 4-3-2-1 (order goes from left to right, brand new previously)

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Plug for cylinder #2 is darker than the rest as well.

We were trying to figure out if the CAS was inverted along with different plug wire configurations to try to alleviate to no run condition. All we managed to get was some back fires on the improper configurations. Cylinders 4, 3, and 2 are dry on the piston tops while the number 1 cylinder is wet.

Compression test results:
110(1)-110(2)-70(3)-90(4)

This is on a fresh motor with new rings. We have been trying to get it started for a while so we are unsure if the rings and walls are still fine or if it needs to be pulled again.

Mechanical timing is set correctly.

Profile is up to date, any help is appreciated!

 

[92AWDHX40]

Looks like you have low compression in some cylinders, that could be it right there low results. Spark , fuel, and compression.

 

[onefast2gdsm]

Did you set your cas to mid range? That will allow you to start the car, but you need to set ignition timing after its warmed up. I'm in Newport hit me up maybe we can get together.

 

[90TSI717]

What's "setting the cas to mid range"? Haven't heard of that before.

 

[eldiabloz13]

turn the cas 180* thats what he means.

 

[92AWDHX40]

I would recheck compression results.

 

[LiquidX]

Did you set your cas to mid range? That will allow you to start the car, but you need to set ignition timing after its warmed up. I'm in Newport hit me up maybe we can get together.

We did lock the timing pin via ECMLink so it would have been running at 5* but that was without luck. Forgot to mention that in the post.

We are both stumped on this right now and it does suck something fierce.

Iugrad, remember, this is on somewhat new rings, compression would be off a bit until they seat, however that's not out of the question either.

Would like to do a leak down test but we don't have the tools for that unless you can somehow convert a compression tester to accept an air compressor line?

 

[jake920]

I just had a similar problem with my latest build. I never checked the compression and i hope your lower #s are a mistake. my problem turned out to be a bad coolant temp sensor.

 

[snowborder714]

Mike/Scott, I have a HF leakdown tester if you'd like to borrow it at some point.

Not to get real basic on you, but have you tried/checked everything in this post?
http://www.dsmtuners.com/forums/articles-miscellaneous/217951-how-diagnose-no-start.html

Have you tried:
-different CAS
-different power transistor
-different plug wires (or tested yours)
-different coil pack (or tested yours)

Do you have a way to view fuel pressure?
Have you verified you have no blown fuses?

A lot of good things to check in this thread.
http://www.dsmtuners.com/forums/newbie-forum/413366-cant-get-new-engine-start.html

 

[90TSI717]

I just wanted to update this thread for future searching. After many hours of troubleshooting, I finally gave up and took it to JNZ for some diagnosis. The only problem with it was 2 of the wires to the IAC were switched. The reason I didn't catch it was, the sensor still functioned (moved in/out) when I turned the key to on. So it appeared to me to be working. I won't make that mistake again!