I'm getting a stumble at idle while in drive. Almost like a quick miss. It'll idle fine but then stumble, and return to idle. after about45-50 secs of doing that every 10-15 secs. it dies. Restarts fine and idle fine until it goes into closed circuit(using the o2 sensor to judge fueling). I have the mopar performance injectors installed, a fpr with fuel pressure set at 30(no boost). I have ran new vac lines for everything and have eliminated the charcoal canister and the pcv. no vacuum leaks that I can find. Basically the only things that are being ran from vacuum is the MAP, fpr, manual boost controller set loose so waste gate actuator is doing all the work. It runs great up top and everywhere in between. oh, I also have new plugs, wires, cap, rotor, and msd coil. Any ideas?
1990 Pontiac Sunbird GT turbo
-TGP turbo
-DSM SMIC turned TMIC
-Injectors
check the iac and throttle body could be just dirty maybe. i had a 3.1 that always idled funny changed every sensor on the engine,intake gaskets computer but it never changed didnt ever stall though
Oh, I have ideas. You're in the same situation I used to be in when I went to the big injectors. The problem is it's running too fat at idle and low speeds. Are you setting a code 45?
You have a couple of options:
1) Pull them out and, put the stock ones back and add extra injectors that only spray under a certain PSI of boost.
2) Add an FMU and get good at tuning it. I never did but I'd be happy to sell you my old FMU.
3) Invest in Tunercat, Tunerpro or some other laptop assisted tuning program so you can change the injector pulse width at idle. Then, move to Massachusetts or New Hampshire, get friendly with Slowolej and hopefully have better luck than I've had with tuning the computer! Maybe he has a cousin in your state?
Seriously, you have too much fuel at idle and low speed. I had to run 20-23 psi fuel pressure (with no vacuum) to get it to run clean and stop stalling. Problem is when you do it'll melt down under boost with pressure that low. Hence the FMU.
If you need to, email me at olzkng@aol.com and I'll tell you whatever I know.
Tony
Tony
1987 Sunbird GT turbo convert
Ported intake, Fiero 53 MM TB, 52 lb inj, ported and flowed head, tube header, Mitsu TD06, ARP rod
bolts/head studs, adj cam sprocket, 4" x 12" x 31" FMIC, Paxton AFPR, modified 125 trans/LSD
unit/3.42's, custom chip tuning, Alky Control Methanol injection
13.61 ET at 101.44 mph, 262 WHP/350WTQ
2009 Pontiac Solstice GXP roadster, 2.0 turbo w/GMPP exh, CAI and turbo upgrade, 290 hp/325 ft lbs
1969 Olds 442 convert
400 Eng, 200-4R trans, 3.73 posi, power everything, OAI
I though it might be loading up... Check engine light has never come on before... I think it might be burnt out. I paid $500 for the whole car and it was in pretty sad shape, engine and drivetrain wise. I wouldn't surprised tf they left the light on for years before I bought it. I"ll read up some more on the Tunercat... and Tony, I emailed you too--
1990 Pontiac Sunbird GT turbo
-TGP turbo
-DSM SMIC turned TMIC
-Injectors
