Help!! Motor running way rich

[TJ SCHULZE]

I have a 1990 Dodge Daytona, 2.5 with 16v 2.4 stratus head and intake. I am running a a GT35R turbo set at a max of 15 psi. This is a 5 speed manual trans car. The motor has about 400 miles on a fresh rebuild. This is the second motor of this setup in this car. I spun a bearing on the first motor after about 25,000 miles.
About 150 miles ago I fried my sbec (fwd stage 5 cal) and swithed out to my original stock computer. I ran this computer on the original motor while waiting for the fwd sbec and had no issues.
With the stock computer i am running way rich. i can kill a set of plugs within 25-30 miles. I have put the stock injectors back in, i put in a stock map sensor, a new o2 sensor, i have checked the tps and it is good. My fuel pressure is 55 psi at idle. i even went back to the stock fuel pressure regulator. Hep sensor is good and timing is set at 12 degrees. Cam timing is set at the stock 2.4 setting and it does have the stock 2.4 cams.
This motor ran great with this exact same setup before and i am out of ideas as to what is causing it to run so rich. Any help here would be greatly appreciated.
Thanks,
Troy

[tryingbe]

What wideband do you have installed?

[TJ SCHULZE]

No wideband, just an A/F gage.

Do you still have that ajustable fuel pressure regulator for sale?

[The Pope]

what vac is the computer seeing at idle? A big leak can cause the vac at the map to drop and in goes the etra fuel. Where were these injectors sitting? They may be stuck open, but it sounds like all 4 plugs foul so I would look at the map vac. Double check map and injector parts number again as well. You have have put in a 3 bar by accident. Lastly the fuel return is something to look at, but you have good idle pressure so it is doubtful as a problem. New sensor come stuck in lean mode and stuck in rich mode. May have a 02 sending out an extra lean signal.

[TJ SCHULZE]

i will check all of that when i get off work today. Thanks for the ideas.

[TJ SCHULZE]

I checked the map and injectors. They are the ones that came from the original 8 valve head. definately the stock ones. I pulled the fuel rail and spun the motor over and the injectors have a good spray and are cycling correctly, didn't see any leakage. It is all four cylinders that are fouling out on the plugs. I have a steady 20 inches of vac. at idle as read on the in dash gauge. The A/F meter i have installed is cycling between lean and rich just as it always has.
While i am fairly sure that i do have the original stock factory computer in the car, i was thinking and it is possible that the computer is actually out of a 1991 vnt turbo car. When i originally converted this car from tbi i used a 1991 underhood harness and the one i bought came with the computer. I don't know if running a vnt computer would cause this problem. This may not be the computer i was running before i got the fwd computer. If this is the vnt computer than i no longer have the regular turbo computer.

[The Pope]

The car should be very lean, not rich. So something is very fishy. It would actually run better with FFVs or +20s and a stock cal and map. So something isn't matching up. Fuel pressure, map, injectors or the 02. If you were complaining about really lean I'd be convinced the right matching parts were in there. Did you actually look up the injector part numbers and the map part number? Or did they look stock? My 3 bar maps look just like a 2 bar, the injectors aren't much different. 804s, +20s, +40s and my 85 lb injectors are identical. At this level you should already have a scanner to watch 02 feed back and watching for knock, the OTC 2000 is about $25. At this level you should have a wideband, a cheap narrow band can be stuck in lean mode flooding the engine... At this point it is still guessing. Even the factory computer has a part number to check. Need to get a list going.

[TJ SCHULZE]

The map senor is a bwd from oreilly auto, so i know that is a stock unit. The part number matches. The injectors were kept in a sealed bag that was marked with what they were. I'm confident those two items are what they are.

I will see if i can pick up an otc 2000 tomorrow after work. never used one and don't know if i can even find one locally here, but i will give it a shot.

I will pull the computer tomorrow after work and check the part number on it.

This car was my daily driver when i was still living in Wyoming. I came down here to Phoenix 18 months ago and just finally got to bring this car down here. Which meens this car sat for 18 months without being so much as even being started. And yes, it was properly prepped to be left sitting. I really need to have this car as my daily driver again.

[GLHNSLHT2]

odd that the O2 is cycling and it's still fouling plugs. Maybe you have a bad ground and it's not giving the ECU a correct reading from the O2?

[TJ SCHULZE]

I will ohm out the wires from the O2 sensor to the computer tomorrow also. With this old of wiring you just never know.

[tryingbe]

If you are in AZ, we have a TD specialist in Mesa. Located at Mesa Dr. and McKelips. His name is AJ, 480 969 5985

[bfarroo]

the FP is set with the vacuum line unhooked right? 55 is a little high if it isn't.

[TJ SCHULZE]

Quote:

Originally Posted by bfarroo the FP is set with the vacuum line unhooked right? 55 is a little high if it isn't.

55 psi at idle is within normal specs.

I do believe i have found the problem. I had a broken wire from the map solenoid to the computer. Not sure why this was causing the problem, but after i soldered and heat shrinked the wire the rich problem seems to be resolved.

I did find out that the computer is from a 91 vnt vehicle. I am waiting to hear back from boost button as to whether i need to find a different computer to put their reprogrammable chip in.

I also just ordered a Innovate wideband, so i should have that pretty soon.

The next issue will be getting the car to pass emissions here in Phoenix.