My 90 TSi still won't run right WTF!?!?!?

[99 gst 420a dsm]

This car is pissing me off like you have no idea, its has good compression, new plugs, wires, coil pack, fuel filter, fuel pressure is good, has new cam pos. sensor, checked all hoses for leaks, mechanical boost gauge installed and the car makes 9psi at 4000rpms and max vac. is 10 while driving, 12 while idleing, the spark is strong, the biss is fine, it doesnt have any low end power, and dosent make any power till 4000rpms. the wastegate works fine, turbo is in great shape on the compressor side, dosent leak or burn oil, blow-by is almost non-existant. fresh oil change, changed is pipes, and bov, air filter, fpr has been changed. the a/f mixture is good also. If you hold the car at 4000 rpms while sitting still it sounds little broken up. While under heavy accel. i can hear come type of clicking, sounds like a solonoid. I have bypassed the egr and still no change. mas has been changed, The car is bone stock accept for the open stainless muffler. Any thing you can think of will help!!!

 

[steve]

max vac. is 10 while driving, 12 while idleing

That's a serious problem possibly caused by retarded ignition timing or mistimed cams. Your idle vacuum should be about 19 in hg.

Steve

 

[99 gst 420a dsm]

That's a serious problem possibly caused by retarded ignition timing or mistimed cams. Your idle vacuum should be about 19 in hg.

Steve

its was just timed perfecty

 

[1GDSM2k3]

ecu??

 

[99 gst 420a dsm]

no CEL

 

[orangedsm]

There doesn't have to be a CEL to have an ECU problem.

On my 92 TSi I was having all sorts of problems, studdering, fuel cut at 5000rpm's on stock boost, and many other little problems. Pulled my ECU, opened it up, smelled like rotten fish. Borrowed a friend's ECU, and *POOF* all problems gone, car ran perfectly.

 

[Irrational]

Hows the warm idle timing belt could have jumped a tooth or 2

 

[99 gst 420a dsm]

Hows the warm idle timing belt could have jumped a tooth or 2

again, the timing is perfect, both belts, and ign. timing, all A+

I dont experience fuel cut but its kinda broken up sounding after 5000rpms while driving, for now im ruling out a bad ecu and going with either and intake gasket leak or a boost leak elsewhere

 

[5150DSM]

Sounds like a major boost leak, I would make or borrow a leak tester and run a little test. Check the intercooler pipes, especially at coupled points and very thoroughly check the throttle body seal. A spray bottle with soapy water will help point out any leaks and listen intently for hissing air coming from anywhere in the vaccum system. www.vfaq.com has the complete procedure.

 

[99 gst 420a dsm]

Compression:

(~120) (~120) (~120) (~140)

Sprayed oil in the cylinders and they came up to ~145



bad rings?


-plus the throttle body shaft seals leak boost/vac

 

[dsmjedi1]

check this out.....
http://www.dsmgrrrl.com/FAQs/compression.htm
it says that if you gain 30+ psi in each cylinder after doing the oil test it is worn rings. your numbers went up by 25psi so that is pretty close but still not 30 or above. either way you need to rebuild the block, the head, or both, because the service limit is 121.....

 

[99 gst 420a dsm]

I ordered the rebuild kit this after noon.

 

[dsmjedi1]

good idear..you'll love the extra compression after you rebuild the motor....good luck!