got a 91 hatch dx just did the swap from dpfi to mpfi everything seemed to be working fine at first then had to change head gasket. now im not getting any spark and my fuel pump is not priming. iv checked the fuses could find any that were blown and i checked the main relay, it seemed fine. im thinking it may be the ecu but not sure the motherboard looked fine. please help any suggestions will be appreciated

 

did you touch the starter at all? I just had a similar problem after a Z6 swap. It was a weird fix. We missed the ground wire when putting everything back together. As soon as we attached the ground wire we heard the fuel pump prime, and then fuel made it to the rail. But in my situation the problem with spark was fixed by replacing the coil.

 

Check the valve cover ground! I'm pretty sure the fuel pump can prime without the ECU though, so maybe you are just missing the sound? It is pretty independant of most of the systems. The fuel pump is connected to fuse 14 and the main relay.

 

where is fuse 14? Is it inline with the starter? This has been on my mind all night while at work. I can't figure out how my starter ground wire caused my problem. Seems so odd.

OP, let us know what you find out! I'm always curious about these kinds of things!

 

For the spark issue check out this video it is what I used to diagnose my no spark issue in my si. . As far as the fuel pump. Did you guys touch anything dealing with the fuel pump or no?

 

I thought it was under the dash. Not even really sure where fuse 14 is.

 

#14

 

check the engine-to-chassis ground... or add another one (I had same problem, this seemed to work) as far as not getting fuel, i would just replace the main relay. (Fuel pump sometimes would prime, and sometimes not till i changed it. Then it work great.)

 

Also, note the corner where it says to use the same size fuse. I hate when people replace a blown fuse with a larger one so it won't blow.

 

replace the relay and i know the pump is not priming there is no fuel at the rail. i just replaced the dizzy and that did nothing i would assume my next step mwould be grounds.

 

Grounds should have been an earlier step, but better late than never 0_o
If it is a ground issue, then you are likely getting a check engine light as well as a solid ECU LED.

 

yea im not sure why i didnt check the grounds first... just a little annoyed at my self. and the cel never comes on and ive tried 2 different p06 ecus

 

Maybe the ignition switch.

 

i kno its not the ignition switch all the dash lights come on when i turn the key and the engine also turns over, just wont start.