Overboost cutout, pig rich, and some other gremlins, possibly related
Hey all, I've been working on making a recently acquired basket case 1989 Daytona Shelby awesome again.
The car is a 2.2 Turbo 2 with a TL;DR list of mods, including FWD-P Stage 5 computer, +40%s, meth injection, block bored .030 over, Menegon ported head with 1mm os valves, 94 TBI camshaft, ported intake, exhaust, 52mm tb, FM T3/T4 turbo, and 3inch exhaust.
When I first start the car, the wideband reads rich for the first few minutes but otherwise drives normal and then settles down around 13.8-14.8 (normal I believe) After this, whenever I hit the gas, the A/F ratio spikes to 15-18 and the car sputters, but then quickly picks back up. It's less drastic If I push the throttle in very slowly.
After about 10-20 minutes of driving, the fuel mixture switches over to pig rich, and the wideband is showing between 9-10.5. Strangely though, the hesitation/sputtering is gone. I think it's going into closed loop, because it reads exactly as it does when the car is first started.
Also the car hits overboost cutout at 5psi for some reason. I reset the computer and went on a short drive, but only got codes 12 and 55. Since resetting I haven't driven hard enough to hit overboost or long enough for it to go pig rich since. I had a code 45 earlier for overboost, and a 23 a that turned out to be a shorted wire to the air charge temp sensor. I remedied the short right before resetting the comp, but it had essentially no effect on how the car drives. The sensor was relocated from the manifold to the intake tube by the previous owner for some reason, with the wires strewn across the intake. I'm thinking they might be getting warm and causing more resistance. Could that make it revert to open loop?
Any ideas? I'm not sure if all or any of these issues are related. It seems more of a basket case. I'm gonna recheck timing tomorrow. I never figured out the vaccuum advance on the dist, but at idle looks to be right at 12 before TDC. Maybe the cam's a tooth off or something.
1991 Spirit ES 2.5 T1, Garrett turbo, fmic, stage 3, +20s, 2.5in exhaust - Fender bender. Parked pending bodywork
1989 Daytona shelby. 2.2 T2, Menegon head, 1mm os valve, Same side FMIC, 3 in exhaust, +40s, 84 checker interior
2009 Honda Civic Si (S-low)
2.0 i-vtec, 6speed. The boring daily. Totally stock, staying that way.