Need help..

DaKine

New member
Picked up the Sy a last sunday and everythings is good. I needed gas so i went to Shell to fill up (usually use Chevron) .. after topping off with 91 i went for a cruise. After about 15 miles or so .. when i get into boost after 7 or 8 psi it knocks and retards timing/boost.
I got a bottle of NoS offroad octane booster .. helped the knock problem. but now there might be another problem.

Didnt get to do the scan tool .. Knock has pretty much stopped (was the gas) but was troubleshooting the lack of accelartion problem last night. I dunno but it seems like the trans is slipping.

When going from a stop and if i get on it almost seems like the trans short shifts to 2nd at around 4g. Boost feels fine when accelrating from a dead stop, its only in The higher rpm's it slows down and feels like im not boosting anymore. The stock boost gauge dosent drop below 12psi. But when going 60 - 65mph speeds and if i get on it it the trans kicks down to 3rd and momentaraly boost kicks in and the gauge (stock) goes to 15psi, then it pulls and shortly after i get some pretty good vibes accelaration is slow and the rpm is climbing really slow 3000rpm, 3100rpm, 3200rpm, all while boost dosent drop much maybe 10 - 14psi. I dont think that its the motor or turbo because when i let go of the gas it releases the pressure (Psssst sound). If i accelarate with half pedal it pulls fine, i stay in boost 12-14 and accelrates damn good for only half pedal ... its only when i go wOT. it does it. This sux :rant:

What do you think? Is it the tranny or motor?

Im gonna have a mechanic friend of mine troubleshoot it and get a second opinion .. if worst comes to worst I can have the trans beefed up and rebuilt with a 2800 converter. (or if anyone can suggest a good combo)

Thanx
 

bezerk

New member
Re: Need help..

get a datamaster and do it yourself...you don't want to have a friend that is trying to fix something, and try it if it still cuts back at WOT...than your friend will help you buy a new engine.


stock boost gauges suck...don't trust that one..you could also have a voltage drop at wot...causing your boost sensor to be slightly off..

Datamaster and aftermarket boost gauge is what you need
 

super-gt

New member
Re: Need help..

Just out of curiosity......can you hear any exhaust leaks? I had a problem somewhat similar with my truck, although I have a S-gt and not a sy/ty. My truck felt like it had no power at all what so ever. It also felt like the tranny was slipping BAD when you would give it a good amount of gas, so I was suspecting the tranny. The problem progressively got worse to the point where giving it like 1/8th-1/4 throttle it felt like it was slipping and it couldn't get out of it's own way. I was next to the exhaust pipe while my truck was idling one night and realized hardly any exhaust was coming out. The next day I tooke the cat off and hollowed it out. It has been runnin like a champ ever since. It is amazing what a clogged exhaust can make your truck do. I dunno if you are having the same problem, but I am just throwing out suggestions. Best of luck and hope you get the beast runnin good again very soon!
 

DaKine

New member
Re: Need help..

can i use tunepro instead of datamaster? and i need a aldl cable where can i get one asap? been using the search and reading about tuning and wanted to look into it.

Thanks
 

DynaGlide

Ton-Eighty
Re: Need help..

Check all your vacuum lines for cracks and proper connections. Do a bike tube pressure test; listen for any leaks in vac lines or in the throttle body (TB).

Also, might be bad compression due to broken ring(s) or ring lands.
 

DaKine

New member
Re: Need help..

DynaGlide said:
Do a bike tube pressure test; listen for any leaks in vac lines or in the throttle body (TB).

.


whats a bike tube pressure test?

I will check compresson and for a exhaust leak.

Thanks again.
 

DaKine

New member
Re: Need help..

super-gt said:
Just out of curiosity......can you hear any exhaust leaks? I had a problem somewhat similar with my truck, although I have a S-gt and not a sy/ty. My truck felt like it had no power at all what so ever. It also felt like the tranny was slipping BAD when you would give it a good amount of gas, so I was suspecting the tranny. The problem progressively got worse to the point where giving it like 1/8th-1/4 throttle it felt like it was slipping and it couldn't get out of it's own way. I was next to the exhaust pipe while my truck was idling one night and realized hardly any exhaust was coming out. The next day I tooke the cat off and hollowed it out. It has been runnin like a champ ever since. It is amazing what a clogged exhaust can make your truck do. I dunno if you are having the same problem, but I am just throwing out suggestions. Best of luck and hope you get the beast runnin good again very soon!


I will look in to this... thanks
 
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