Whats the problem?

[2g4me]

Ok we installed a EVOIII turbo in my friends 2g AWD talon he just got and hasnt even driven yet (got it without a motor, previous owner blew it), dropped a 7bolt in it with a built bottom end and rebuilt head, everythings good...starts, runs and drives no problem, but heres were the problem lies...Goes into boost when it should, stays steady about 15-16psi and pulls good, RPM's shoot up till about 5k then just slowly climbs to redline. Theres no hesitation as far as cutting out or stuttering or anything like that, it just acts like it doesnt want to go anymore even tho the boost is there. Now my GSX will hit redline (9.5k on mine) like it cant wait to get there and ive never had this lagging problem so i dont know what to tell him...Brand new stock injectors o-rings and seals, new walbro 255, new fuel filter and FPR.......Any thoughts why this might be happening?

 

[2g4me]

Hes using the stock non-eprom unflashed 96 ECU, no afc or anything so the computer is doing all the work, im not paying attn to the timing since the ecu wont change it enough to cause this especially when its doing it at any boost level, im just making sure the air and fuel mixture is good, and its fine. Who knows maybe there isnt an answer to this but i havnt lost hope yet,

 

[dsmike1]

excuse my newbieness to the whole tuning part i dont have much input for that. but i am a mechanic and i think it could be a restriction in the exhaust, is there a cat. on the car? what kind of exhaust? try unbolting the exhaust before the cat, or test pipe and take it for a ride. just a suggestion

 

[2g4me]

excuse my newbieness to the whole tuning part i dont have much input for that. but i am a mechanic and i think it could be a restriction in the exhaust, is there a cat. on the car? what kind of exhaust? try unbolting the exhaust before the cat, or test pipe and take it for a ride. just a suggestion

Its cool, has a 3" turbo back, no cat....And no thanks, this isnt a Honda!

 

[dsmike1]

brrrr wahhhhhhhh. how could you not love the sound of a foldgers can welded to a 1 1/4" exhaust

 

[blkgst97]

can you take an in car vid so we can see how dramatic this problem is? and how hot is it down there? I am no tuning wiz and someone will probably answer this but on 91 and 11.5 afrs with a core that is not the greatest especially in hot weather wouldn't that be enough to cause some knock.

 

[2g4me]

can you take an in car vid so we can see how dramatic this problem is? and how hot is it down there? I am no tuning wiz and someone will probably answer this but on 91 and 11.5 afrs with a core that is not the greatest especially in hot weather wouldn't that be enough to cause some knock.

Lol, its been mid 20's to low 30's the past week here, its nowhere near warm, let alone hot. If the weather is affecting it at all, my afr's would tell me but with 10-11 AFR's, it would have to be hot as phuk to cause knock.

I dont know guys, its just really strange and odd that it pulls good then just loses power up top under the same boost...I dont get it!

 

[gusu]

gusu, you have the right idea, but I don't completely agree that more than 10psi on a 16G would with any certainty cause him to reach fuel cut or staticly open the injectors. IIRC, 1G fuel cut is reached at a lower airflow than the 2G limit. I ran 17-18psi spiking to 20ish on a 14b with a stock 2G fuel system and MAS and never logged more than 90% IDC. Use a datalogger. If you see more than 90% IDC or more than about 2.3-2.4 grams per revolution of airflow (stock 2G fuel cut happens at 2.5 g/rev) turn the boost down. If you hit fuel cut, you'll know it without a doubt. When the injectors are shut off at speed, it feels like you just slammed into a brick wall.

2g4me, the stock ROM is very conservative in the upper rpm range, it targets richer than 10:1 AFR in some cells. Try leaning it out a little there and see if you can add a couple degrees of timing without getting knock. I'll bet the car will feel much better. -Now, with all that said, you should be installing bigger injectors very soon.

Doh, I was thinking 1g MAF for some reason. Not sure why, off day for me

 

[sugarfree]

man i'm having the same problem and all anybody said when i asked was the "all problem fixing" boost leak test Try this next time you drive your car, right after you start it up and get maybe a mile down the road stand on it and see if it still does it. I am lead to believe in my case it's 100% timing being pulled due to engine temp because my car feels ridiculous fast until it's fully up to operating temp then it does the same thing yours does. I am also running stock injectors but just like you my a/f"s are int the 10-11ish range during boost so it's obviously not being retarded due to inadequite fuel supply. I just gave up on it till i get link and am able to log some pulls and see if maybe it's a bad coolant temp sensor or something silly like that.

 

[2g4me]

man i'm having the same problem and all anybody said when i asked was the "all problem fixing" boost leak test Try this next time you drive your car, right after you start it up and get maybe a mile down the road stand on it and see if it still does it. I am lead to believe in my case it's 100% timing being pulled due to engine temp because my car feels ridiculous fast until it's fully up to operating temp then it does the same thing yours does. I am also running stock injectors but just like you my a/f"s are int the 10-11ish range during boost so it's obviously not being retarded due to inadequite fuel supply. I just gave up on it till i get link and am able to log some pulls and see if maybe it's a bad coolant temp sensor or something silly like that.

If coolant temp was the issue, it would throw codes either insufficient coolant temp or closed loop issues. His coolant stays below 1/2 and never goes any higher.....remains a mystery at this point, he gets back tomorrow so we'll be tinkering with it some more....

 

[foxyspyder01gt]

brrrr wahhhhhhhh. how could you not love the sound of a foldgers can welded to a 1 1/4" exhaust

Lawls

 

[blkgst97]

Ever get this issue figured out?