90 Electrical Problem

[jjbrasil]

OK, i did an engine swap, tried to start it..wont start...ive cut it down, I have SPARK, Fuel DOES flow through the rail, and i have compression. Im not getting a pulse through the injector harness, so no fuel goes into the cylinder, I am getting voltage to the injector harness when i tested them all for voltage but my test noids just didnt light up while cranking over... i I replaced the ECU, EFI relay, and CAS...what else can cause this?? im soo stumped is there any fusable links? fuses i can check? im out of ideas and im sick of this crap. any ideas u have please let me know thanks

 

[ezell4G63]

Try pulling the CAS off and with the ignition on turn the CAS buy had, you should here the injectors clicking. Also I believe if the CAS is 180 degrees out of rotation it may not fire. I had a similar problem awhile back. Hope this helps

 

[jjbrasil]

i did not here the injector clicking, i also pulled the fuel rail out with the injectors still in the rail....to see if fuel even came out..and no fuel came out of the injectors, any other ideas are NEEDED...just throw anything at me cuz anything will help right now..thanks

 

[jjbrasil]

i tested for resistance from the injector harness back to the ecu harness and got resistance on all 4..wtf its not adding up! swapped, ecu's, Cas, EFI relay, mpi fuse is fine, have a complete circuit? is there something im missing?

 

[Number1gkid]

buddy i hear you.i have the same damn problem and i cant seem to figure it out.its funny cause the way you describe it its identical to what i probably would have posted.sorry i cant help you i got the same problem.if you figure anything out please let me know.thanx man.

 

[CYCLONE]

This might sound stupid but have you tried the fuel pump relay.
There are actually 2 relays inside of that housing. One is for
the pump, possibly the other one might have something to do
with the injector circuit.

 

[Number1gkid]

where is the fuel pump relay location?

 

[CYCLONE]

Ist a gold colored metal housing, Its mounted right in front of the
ECU, below the radio.

 

[jjbrasil]

its called the EFI relay...and yea i replaced that when i turn the cas by hand i can here it click and then when i stop turning the cas it clicks again its sounds like its working...any other ideas? this isnt all adding up? is there anything that wouldnt let the injectors fire???

 

[CYCLONE]

Well I had a very similar problem with my 90 fwd turbo
never actually checked if I had injector pulse because
the same day it didn't want to start I went and got another
ECU. But as soon as I plugged it in and turned over the motor
I saw smoke come out of the new ECU so I took the cover of
and found one of the resistor blown up. Took it to AMS
they said to disconnect the ISC before I plug in another
ECU. Did that and the car started right up, apparently if the ISC
shorts out it will destroy the ECU. Try another known good ECU
with the ICS unplugged.

Sorry didn't think of this earlier.

 

[laserblue]

Warning... this could be a stupid question, but I don't know any better....
Is the new [swapped] engine the same as the old one? [year, size, etc.??]

 

[jjbrasil]

The engine MIGHT not be a 90 6bolt, the guy just told me it was a 6bolt it could be a 91 im not sure, would any of u guys know whats compatible and whats not...like the wiring harness and stuff like that, Im still using the same intake manifold exhaust manifold and sensors comin from the intake manifold from my old motor the only thing that i bought was the BLOCK and CYLINDER head thats it..and if there is a 'fix' when swapping non-identical engines!!
lemme know what u guys think thanks

Joel

 

[jjbrasil]

today i took a voltmeter and i got a pulse while spiining the CAS...so i guess i AM getting a pulse, I also checked for short to ground...i took one lead to the neg terminal, the other lead to one injector pinout on the ecu harness and unplugged all the injector harness sensors and i got nothing...i here thats good, but then when i plugged the sensors back in i got nothing still, on for 1 injector pinout i got resitance?? is something not right there?? i thought with the injector sensors pluged in i should be getting resistance? let me know what ya think