Acceleration problem

[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. 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.

[Kracka]

You installed new injectors and have all your tuning devices set to zero, you're dumping in almost 50% more fuel than your ECU thinks so of course your car isn't going to run right. Get that pig tuned.

Get a real air filter too, those knock-off cotton gauze filters flow no where near what a K&N or other brand-name flow.

[A//// Guy]

Make sure your MAFT is set to use 660s also...

[gstjoker]

I tried setting the maft to 660s and it made no difference.

As for the filter, does it really matter? Here's a picture and link to expand it.

[Kracka]

Originally Posted by gstjoker

I tried setting the maft to 660s and it made no difference.

Check for boost leaks then. If you can't do it, drive it to any of the local shops and have them do it.

[FattyBoomBatty]

Put the old stuff back to how it was, drive to dyno, install new injectors in the parking lot before getting it tuned.

[Tman1gtsi]

I had the same problem and I think we found that the plugs had been destroyed--too much fuel while home tuning safc but then it fixed itself, so lettin ya know I feel the same wrath everyday, it goes from working to not-working

[sleepydsm]

When I replaced my fuel injectors once, the injector insulators that go in the intake manifold were super brittle and cracked, and they made such a huge vaccum leak that the car wouldn't even stay running. Definately do a boost leak test and get back to us.

[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"??