Hey everyone, I'm new here, my name is Christian and I was having some issues with my 91 Honda Civic EF Hatch w/ A D16A6. It cranks hard but does not turn over, I have tried replacing the main relay and tightening up my thermostat ground and when I changed the main relay, the fuel pump stopped priming. I tried a few times with the new relay and it cranks with less power and the fuel pump won't prime. I changed the old main relay back in and the fuel pump primes and cranks harder than with the new one. Does not make sense to me. Some background about it is I converted to mpfi from dpfi myself and also did the swap myself. It was all working well and great so I know it was nothing with the mpfi conversion or the swap itself. My friend messed the transmission up and I replaced it with another one and it was working fine for a few days and than while on the way home was sputtering out while I was driving and I got it home to park it. Hasn't moved since and won't fire up. Does anyone know what it could possibly be by my description. Sorry for the long post I just wanna be thorough with my first post. Thanks so much and id appreciate any comments or feedback on what you think it could possibly be or have had experience with this problem. Thanks

 

Check your wiring, possibly a loose or bad connection from the dpfi to mpfi swap. Is it still getting spark?

 

Not sure this would cause it but there is a ground that goes to the transmission. Is that still secure?

 

I rechecked the wiring and I was getting a check engine light before and I switched the IAT and I think the IACV as they have the same plug? Check engine light went away but my ECU does not light up the led light at all, even when I had the check engine light and the service connector jumped. I have rechecked all the dpfi to mpfi wiring but was wondering if you could tell me the location of the transmission ground? I have the thermostat ground and valve cover ground hooked up. Didn't know there was a transmission ground except for the one that connects the negative battery cable to the transmission. Have that one hooked up also. I am running around in circles, I appreciate your feedback as it is a different approach and it helped my check engine light go away lol.

 

Different car (just grabbed a pic from the google machine), but that's essentially it. It should attach to a bracket I believe just like the picture with the other end just bolted to the chassis.

http://www.honda-acura.net/diys/civi...lywheel/25.jpg

 

I do have that one hooked up as its my main ground to the battery cable and wouldn't crank if that wasn't hooked up. Any other ideas ? Thanks for your help I appreciate it.

 

Maybe need to go back to basics. Verify spark and fuel, and compression if you can at the moment. Check for color of spark. Also, might try to hook that battery ground to chassis since the chassis itself is supposed to be a universal ground.

 

I don't have the means to check compression right now but I will check for spark and fuel. And I will try to switch the ground also. I appreciate your help, it's always good to have another opinion, it's just frustrating running in circles. Back to basics it is though just gotta go through everything.

 

For what it's worth I doubt it's a compression issue but would still need to rule it out. Spark and fuel is easy enough to check.

 

Yea I'm gonna check that later today literally have a headache from this car. Can't give up though, just gotta keep going with it. Thanks for the info, I'll be back on it soon with an update.

 

It sounds to me like either a brittle wire broke or the relay under the driverside dash you said you changed . The fuel pump relay you changed.right. do you have a way to test the fuel pressure after the pressure regulator. When you first turn t he car on ( not start) do you here the fuel pump start up? You should have 35 to 50 psi.

 

Also you haven't moved your plug wires around maybe not on the right tower.