Pulling my teeth out of the steering wheel...

[just_passed_you]

The very second my boost gauge reads 0, turbo is spooled... FUEL CUT or at least it feels like it. I checked for shaft play, turbo wheel still spins, no play. If my IC pipes were loose I'd still be able to accelerate without that feeling, just no boost. Thank you GM MAF. This is different, I'm pulling my teeth out of the steering wheel trying to boost. SAFC is 0'd out, ECU has been reset, MAFT is set for injector compensation and 0'd out as well. Would a boost leak feel like this or would it just feel like no power durring exceleration? I know it's getting fuel, at least it smells rich as hell if I keep the gas pedal steady, just the second I open it up enough to boost BAM ouch. WTF Car was running great, honest to God all of the sudden this. It was raining and I'm wondering if water got into the MAFT or what? If a boost leak feels like mad fuel cut, I'll test it out. I haven't checked the clamp on the Tial BOV since I first installed it could that be leaking? Suggestions?

 

[Maglin]

Definitly do a boost leak check. You shouldn't be hitting fuel cut at 0 PSI. You might have an issue with the MAFT. what is your datalogger telling you for your airflow? That would be a good way to see if you are hitting fuel cut. If you are hitting 1600Hz+ at 0 PSI it's definitly a boost leak or a issue with the MAFT.

 

[just_passed_you]

So do you think a boost leak would feel like the symptom I described? I'm leaning towards the MAFT being the issue as the only thing that changed from yesterday morning to afternoon was RAIN. least I didn't suck any into the turbo although I'm not sure that would do much harm.

 

[Burnett03]

So do you think a boost leak would feel like the symptom I described? I'm leaning towards the MAFT being the issue as the only thing that changed from yesterday morning to afternoon was RAIN. least I didn't suck any into the turbo although I'm not sure that would do much harm.

rain into the turbo would do harm... are you running in blowthrough? There is no way to get water into the maft in blow through unless its sucked through the turbo first.. Do a boost leak check.. When ever anything goes wrong on these cars do a boost leak check first.

 

[oldman]

Definitly do a boost leak check. You shouldn't be hitting fuel cut at 0 PSI. You might have an issue with the MAFT. what is your datalogger telling you for your airflow? That would be a good way to see if you are hitting fuel cut. If you are hitting 1600Hz+ at 0 PSI it's definitly a boost leak or a issue with the MAFT.

Agreed. I 'm leaning towards a bad sensor since you're hitting fuel cut at 0 psi but a boost leak test never hurt.

 

[just_passed_you]

I meant water in the MAFT <-- the translator box itself. It's in a spot suseptable to rain especially with 2 screws missing.... eraghh! $200 bucks down the toilet.

 

[Burnett03]

I meant water in the MAFT <-- the translator box itself. It's in a spot suseptable to rain especially with 2 screws missing.... eraghh! $200 bucks down the toilet.

do the lights blink inside the translator when u make changes?

 

[just_passed_you]

Ok guys, this is the strangest thing I've ever come across but now it feels like a spark issue. Here are the symptoms and what I've done to troubleshoot.

Symptom:
Yesterday as soon as I passed 0 on the boost gauge, a fuel cut feeling motor feels like it dies. If I steady the throttle @ MID I can climb the RPM's so long as I'm not flooring it. If I go WOT the RPMS die, car bucks like mad and then a pause as if I'm just coasting and then all of the sudded another mad bucking and then coasting. It's a rough ride finding out what WOT does while it's like this. Today I can build ~10+psi at half throttle and retain it slightly but trust me, it does not FEEL like 10psi, it's weak!

1.) boost leak test: I'm good past 20 psi and then the DIY tester blew off.
2.) spark plugs: I changed them.
3.) Swapped out my MAF Translator for a working MAFT: no change
4.) Swapped ECU for ECU with DSMLink: no change
5.) Checked for smoke: there is some white but my engine is 120k old, probably rings.
6.) Checked turbo for shaft play: The wheel spins and there's no play
7.) Checked FPR: I'm at 38psi for fuel

I think it's spark, but why would it cut out like that under load? Coil Pack? Wires? I'm stumped. Would a blown head gasket have these symptoms? I gave up last night but today is a new day, same DSM problem. WTF


replaced the spark wires and she runs like a dream! Thanks for the insight everyone! Time to race!

 

[Maglin]

replaced the spark wires and she runs like a dream! Thanks for the insight everyone! Time to race!

Man you changed all those parts for it just to be a bad set of wires. glad you figured it out. Usually bad plug wires will have burnt tiny holes on the boots showing you that spark is exiting out the boot. Not to mention they make a lot of noise as well.

 

[NinjaTech]

Glad you figured it out. I wish I had seen this post sooner, my camaro does this about once a month when it cooks its plug wires on the headers. I have fixed two customers DSM's recently that have done this also. What happens is the plug wire will get damaged a little and have a cut in the insulation, under most normal driving you have very little air and fuel actualy in the chambers and that gives a relatively "low" resistance for the spark to jump thru and it will provide the path of least resistance for the spark to get to ground. As throttle increases you start getting much higher air/fuel densities and higher resistance for the spark to jump across, when that happens the damaged plug wires become the path of least resistance and it will jump there instead of across the plug.

Pat

 

[blackshan]

I had the same problem on almost the same day. Thank goodness I knew what was making my car do it. Thats what I get for letting water get on top of the valve cover while washing it! ! Its funny how dsm's seem to have the same health problems sooner or later.