Laser Problems

[93RS]

I have a 92 Laser RsT and I have been chasing problems on this car since I bought it... It idles super sporadic, the stock boost gauge is way off (aftermarket reading -5 stock reading +7) and also super sporadic with steady throttle input, as well as some cutting out issues after its good and warmed up. It will run fine for a while then it starts cutting out real hard a WOT, then it turns into full blown asthma. I have a hard time getting it to get to 2k without hard bucking. I have replaced the plugs(ngk bpr6es gapped .032), wires (ngk), coil packs, O2 sensor, TPS, TB shaft seals, fuel filter, injector seals, manifold gasket, turbo/O2 housing gasket,and all the oil/coolant lines associated with the turbo... Could anything other then a boost leak cause this? Im leaning towards the MAF due to the gauge inaccuracy but Im not really sure where to turn... Please don't tell me to do a BLT its been done and shes golden! Any and all advice is greatly appreciated!!!

 

[codym]

Did you try unplugging the MAF and seeing how it reacts ? Stock boost gauge is lousy anyhow, assuming your aftermarket is done correctly (nothing personal, just trying to help) -5 seems a bit wierd if your set up at 12 with the MBC. Is your profile up to date? No fuel upgrades, factory turbo, etc ?

edit: you said youve done a blt, have you checked compression?

 

[93RS]

Compression is good accross the bored.... I unplugged the maf and it idled better for a bit plugged it back in went back to its normal.... As far as the gauge discrepency goes I know the stock ones are a guess but sometimes its within reason other times its way off.... Half throttle will usually go to no bac/boost while the stock one is at 7 sometimes 10 and yes my profile is correct

 

[Jake719]

It seriously sounds like you have a fairly significant boost or vacuum leak. With stock cams and internals you should be seeing WAY over -5 at idle, more like -15 on a healthy engine.

For instance, I've got 272's in my GVR4, and Im at over 6k feet in elevation, and I still see around -6 at idle.

The fact that you unplugged your MAF and it ran better is seemingly suspect as well, chances are that has bit the dust. Id recommend trying a known good if you can, or logging to see what it is reading at idle/etc.

Another thing to check would be your vacuum lines to make sure theyre routed properly to the solenoids/etc. A criss-crossed vacuum connection can cause what you're describing (especially if the ones that go through the bracket on the bottom of the intake manifold arent in the right spots).

Hope that helps!

-Jake

 

[93RS]

She reads almost -20 at an idle... Fluxuating of course but its got good vac at an idle nd I'm gonna put my maf off my other 1g on her nd she how she does

 

[codym]

If its running better with the MAF unplugged I'd start looking in that direction..
Have you opened up the ecu at all? If so whats it look like in there?

Read this
Terry's Talon Troubleshooting Tips #3 - Fast Idle (aka. Idle Surge)

 

[DSM1G90]

.032 is a bit wide for the "6ES" plugs ... should be .028

With plugs at .032, I bet you're snuffing out the spark quite easily, esp under boost.

 

[93RS]

Swapped the maf from my Tsi took the laser out for a drive and it ran super good, the boost gauges were accurate to some degree, and it was perfect for like a half hr then it was like a switch..... Then started to act exactly like it used to.... I have the lasers old maf on the talon nd I'm driving her 200 miles tom so it will get a test... yes I've opened the ecu and it looked new... When I get back from Vegas I'm gonna swap ecus and see if that helps anything.

 

[93RS]

I just got a logger maybe some of my numbers will help you guys out.http://www.dsmtuners.com/forums/tuning-engine-management/459226-1rst-log.html