I took out my stock ecu and then was going to put it back in and it doesnt work, the car just cranks. All the 4 of the plugs snapped in except for one, but its in there really tight so I dont know how it wouldnt be. DO the grounds have to be in certain spots? Anyone have a pic or diagram of the set up of the grounds? I just dont understand why it wouldnt work.....

 

Are you doubly sure you got the connectors back in the right way? I imagine the connectors are designed physically to not go into the wrong spot, but when I pulled my ECU for troubleshooting I was paranoid about getting them mixed up.

Not sure what you mean by the grounds thing.

 

Yeah theres no way of putting them in wrong, and I'm talking about the two ground wires that are on the right side of the ecu bolted down.

 

So long as they have a good contact to the body, the grounds should be fine. Did you remove any relays/fuses that you forgot about?

 

no, just unplugged and back in. Do the grounds have to be bolted to the car or to the ecu's bracket?

 

Did you disconnect the battery when you were removing/reinstalling the ecu?

 

the 10mm bolts that hold the ECU in place are where the grounding wires go.

Does the car fire at all??? of just crank and crank.... if so, check the 120 amp main fuse and the "ECI" fuse. They're located in that black fuse block that the ( + ) terminal battery lead connects to. Typically, when poking around, if you accidently short out one of the main power wires in the engine bay.... like the positive one connected to your altenator... you'll blow that fuse. Oh, your engine will crank alright... and crank and crank and crank....

Um... try pulling one of the spark plug wires, & have some crank over the engine. Ground the plug wire and see if you get a spark. No spark.... check the fuses.

 

No I didnt, but I did reset the ecu afterwards.

Thanks Karken I'll try that.

 

And yeah all It does is crank and crank, same thing it does when the ecu is totally unplugged. I'll check the fuse.

 

Naughty! Always disconnect the battery when doing work on the car! Hopefully, you just blew a fuse like Rich's dad suggested.

 

pull the ecu again and see if you bent the pins on that one really tight connector. they should go in firm, but without a whole lot of resistance.

 

Another vote for a bent pin - I've seen that happen before. If so, VERY carefully bend it back - you might be able to get away with it. And, with a problem like this it's always a good idea to check all your fuses.

Dale

 

pins appear straight but we cleaned the plug a bit and it slides in easier. weve put a good main fuse in it and that didnt help...do you mean EGI fuse when you said ECI fuse?...

 

Check ALL the fuses. There's quite a few fuses that don't seem to make any difference, but has something on the circuit that you need. For example, the ABS computer is on the "rear wiper" fuse.

 

every fuse i know of is checked. its getting spark, but no gas. which plug on the ecu would affect fuel?...

 

Just curious, with your mods why are you running a stock ecu. I see on your description you have an aftermarket one. Maybe you should try plugging that one in. If that ecu works, maybe theres something wrong with your stock ecu.

 

long story...off topic...bump

 

bump

 

come on guys I need some help,changed out main fuse, egi fuse and checked many other fuses. The car also gets spark, so I'm out of ideas...

 

Well I guess we stumped the rx-7 community.....

 

well the "3rd gen" community...

 

Well, I suggested swapping in a different ecu. IF the car starts with a different one in, the problem is with the ecu. If not, then the problem lies elsewhere

 

Like pos7 said try using someone elses ECU, and have them try yours.
Also, check when you turn the ignition on, if the CEL lights turns on. If it doesn't, thats an indication of a burned ECU.

 

both check out fine...

 

you try unflooding it yet?