Bad ecu?

[upinsmoke]

I have a 93 s13 with a 96 s13 blacktop engine. Lately I have been having a problem with the engine running really rich, not being able to rev past 3k rpm, a lot of smoke at idle and just running like crap. It recently occured to me that the ecu could be bad because i had a mechanic look at it and its definatly dumping way more fuel through the injectors than it should be. So this is probably because of a bad ecu. It is the e5 ecu. Im just trying to get somebody elses opinion before i try to buy another ecu and try this out. So let me know what you think. thanks.

[drifter808]

Check the mafs. turn on the car and unplug the mafs sensor and see if the idle changes. Not being able to rev past 3000 sound like the mafs is bad. I believe if the ECU is bad the cer wouldn't run at all.

[upinsmoke]

Well, right after you mentioned to check the maf i did. I unplugged the maf and the car idled perfectly so i figured that was the problem. So I took that maf out and replaced it with a good maf that I already had. Car started up and idled perfectly. Alright problem solved. Nope, took it for a test drive and was working for a short while then started acting up again until finally it started dying out at idle and basiclly doing the same thing all over again. Any thoughts on this now? Thanks.

[llteddy4playll]

What are your mods? Is it always stopping at 3000 or its different rpms.

[upinsmoke]

it is basiclly stock. Except I have 3" yoshio exhaust, 3" apexi downpipe, HKS intake, walbro 255 fuel pump, and a nismo clutch. It has been dropping out at different rpms. But mainly dropps out at 3000. Wierd thing is when i changed out the maf it worked good for about 10 mins then it started running like shite and doing the same thing it was beore. Now its cutting off at idle. Its almost like when the car warms up the problem comes back.

[Tenchuu]

I had a buddy that his redtop was doing the exact same things, it was the ECU. look around for someone with a good ECU that you can borrow for a day to find out.

[upinsmoke]

Ah I forgot that I know a dude that just got a blacktop front clip. I just contacted him and he said hes coming over right now so i can test it out. Ill let you know the results. Not sure if his ecu is an e5 or a wc should that matter?

[llteddy4playll]

Checked to see if your maf is wired correctly. Check ur tps too. Boost leak can cause your car running rich too.

[upinsmoke]

well we just swapped a working ecu in and got no result the car is still running the same. This problem just happend recently the car was runnning great before. Anybody else got any ideas?

[drifter808]

Check the mafs wiring and see if there are any boost leaks. Thats all i can think of now. it probably wiring related. just look over all the wiring that was done and check to see if any wires came apart or if any wires are exposed grounding out on the chassis.