Acceleration problems

[gstjoker]

Here is what was on the car before the problem occured:

2g Gst
Evo3 16g, Greddy 24r fmic, Buschur Racing 3" catback with ebay downpipe, no cat, safc2 zeroed out, gm maft v2 zeroed out also, autozone filter with a hard 3" intake pipe, Ngk Bpr7es spark plugs and wires, and a afpr.

After installing my 660 Denso injectors and actually heading out to get it tuned at a shop, right as I drove out the drive way, my accelaration hesitated and stumbled. If I go slowly like really slow, the fastest I would be able to go is 30 mph, no more than that or else the car just bogs like crazy. I try to compensate for it with the translator and safc, no luck. The driveability of the car kind of reminds me of when my intercooler pipes would blow off, but would still be driveable since I had the gm maft. I was getting black smoke even before the injector upgrades.

My only guess would be a boost leak as I haven't done a boost leak test yet. I also tried setting the maft to 660s and still no luck. Could a exhaust leak caused this no good acceleration? It seems like I was getting a exhaust leak where the downpipe meets my catback but I went back and tightened that up. The 2nd exhaust leak seems to be coming from either where the exhaust manifold bolts up to the engine or where it bolts down to the turbo as I see black smoke deposits around those area. I do already have a 255 fuel pump but I was going to have a shop install it for me incase you are wondering about my fuel. The bottom insulators of the injectors are new too. Pretty much the car just went to hell after the 660 injectors install. Sorry for the long description, I need this car running so I can drive it to the shop to get it tuned badly. 10-11 mpg sucks especially with Premium gas price.

 

[SlickGSX]

Possibly a boost leak, check all your IC piping clamps, an exhaust leak before the turbo could also cause that but it would take a serious leak that will be obvious. I used to run a MAFT zeroed out with a AFC as primary tuning source, you could try that as well.

 

[95talon07]

i bet your running way rich. A boost leak would not cause you to only be able to go 30 mph. And no an exhaust leak wouldnt either.

 

[JohnCIV_Talon]

i bet your running way rich. A boost leak would not cause you to only be able to go 30 mph. And no an exhaust leak wouldnt either.

Thats not true at all and I dont know why you would say that??? Have you ever had a ic coupling fall off? Dont say stuff when you dont know what your talking about.

 

[forcefed 95]

^^^^^^^^^^^very true ive had my fair share of ic pipes popping off and iv managed to make it down the road doin 30. hell when my turbo went i was on the highway, would not get boost over like 1-2psi but i did 60 all the way home, and with a smoke screen behind me .. kind felt like james bonds till i got the finger from like 70 people behind me but oh well.

 

[95talon07]

Ok i could be wrong. then explain to me how an ecu would recompensate for the lose of boost to only allow him to go 30 mph?

 

[luvmygst]

Ok i could be wrong. then explain to me how an ecu would recompensate for the lose of boost to only allow him to go 30 mph?

Go pull an intercooler pipe off and go for a drive it will explain itself.

 

[95talon07]

the only reason i said what i said is b/c he just installed bigger injectors, and all his afr's are zeroed out. which means the car should be running way rich

 

[gstjoker]

Good news! I fixed my slow acceleration by switching out the 660s back to my stock 450s. I'll wait till I head back to the shop to get it tuned to put the 660s back in.

However, I'm noticing that I am getting an exhaust leak right where the exhaust manifold meets the turbo. I could see the black smoke deposits around the edges. All the bolts seems to be tight. The exhaust manifold is my stock 2g ported to a 7cm with that hard metal 7cm gasket plate. What's the best way to fix this "one of my many dsm problems"??

 

[always_broken]

Oooh..

Looks like 95Talon07 does know what he's talking about! Gj bro.

 

[JohnCIV_Talon]

Well if you think your so right about the ic piping, go pull a coupler off, not even the hose, just the coupler. Try to accelerate???? Then come back and say something you have had no experience with.

 

[merqury]

In my opinion, its probably a boost leak also the car is running rich. It could be a combination of both. I just finished installing my new setup in my car and I had the same problem. There were boost leaks and the car was running rich as well. I also have wideband so I could tell. A boost leak test and a little bit of tunning and my car was running perfect. When the car is struggling to go try to see if your exhaust is letting out black smoke in. If it is, then the car is running rich. I would check both and then go from there.

 

[Polyol]

I agree. Sounds like it's running real rich. I had the same problem when I upgraded my injectors. Wideband was the key to get mine to run right, money well spent