HomemadeTurbo - DIY Turbo Forum

HomemadeTurbo - DIY Turbo Forum (https://www.homemadeturbo.com/)
-   Engine Management (https://www.homemadeturbo.com/engine-management-10/)
-   -   I need some help. Strange problems during MPFI swap (https://www.homemadeturbo.com/engine-management-10/i-need-some-help-strange-problems-during-mpfi-swap-36230/)

idiot-stick 03-17-2005 05:39 PM

I need some help. Strange problems during MPFI swap
 
Ok, I did the MPFI swap. Soldered everything and just checked over the wiring for the 50th time.

Engine symptoms - runs like total ass, won't idle, but i can keep it running, spurts and farts

Codes 4 - CKP Sensor (Crankshaft Position Sensor) defective circuit or unplugged / defective sensor
6 - ECT Sensor (Engine Coolant Temperature) defective circuit or unplugged / defective sensor
14 - IAC Valve (Idle Air Control) defective circuit or unplugged / defective sensor
20 - Electrical Load Detector defective circuit or unplugged / defective sensor

Ok, here's where it gets weird. When I turn the ignition to ON and after hearing the main relay click, if I turn OFF the car, the ebrake indicator and CEL stay on dimly, ECU flashes repeatedly.
This continues until I either
a) remove ECU plug A for a couple seconds
b) remove ECU plug C for a couple seconds
c) remove the big, round connector near the resistor box.
*After any one of these conditions is met, the lights in the dash go off, and the main relay (or some relay) click off



This problem even happens with the following things disconnected:
1) big round connector on passenger side
2) Both distro harnesses
3) Injector resistor box

I tried plugging in my PM5, of course the car wouldnt run, but this problem went away.

I tried removing the chip from the PM6, this fixed the problem, although of course nothing else would work. I tried a differnt chip, but the problem didnt change.

It seems to me that some sensors arent getting power, but somehow the ECU is being powered when it shouldnt be or something is keeping that relay open.

Could the ECU be faulty? I'm about out of ideas, so any help would be greatly appreciated.
I got the ECU from xenocron. I took the ECU covers off and the soldering looks perfect.

mahcivic 03-17-2005 05:43 PM

Re: I need some help. Strange problems during MPFI swap
 
the CEL #4. did you make sure when you cut the wires at c1 and c2 that you repinned them back into b10 and b12. c1 goes to b10 c2 goes to b12. your car is running in limp mode thats why its running like ass. and ECT and IACV, try swapping the two plugs. i know that the plug that goes to the iacv is green. maybe you mixed them up.

idiot-stick 03-17-2005 05:48 PM

Re: I need some help. Strange problems during MPFI swap
 
OK, well you got me on the green plug. I DID plug in the wrong one ;D. Its too cold to solder outside though. I have checked the b10 and b12 80 million times, but i will check them again.

Im mostly worried about the funky 'lights staying on' problem when I turn the key off. That worries me.

Edit: Thanks!

warric_k 03-17-2005 05:50 PM

Re: I need some help. Strange problems during MPFI swap
 
check your grounds, mainly the thermostat ground. make sure they're clean and tight. check battery ground.

dash light issue is very similar to an issue I had.

idiot-stick 03-17-2005 05:56 PM

Re: I need some help. Strange problems during MPFI swap
 
Battery ground is good. I checked the 2 black wires on the A connector (assuming they're ECU grounds) and they were good. Didnt see a thermostat ground, but its gettin dark outside. Thanks for the advice. Its gotta be some kind of grounding issue :(

idiot-stick 03-18-2005 12:46 PM

Re: I need some help. Strange problems during MPFI swap
 
I got 2 hours till im done with work, any other ideas on this?

Im still puzzled why this problem doesnt happen with the known-good PM5.....

idiot-stick 03-18-2005 03:46 PM

Re: I need some help. Strange problems during MPFI swap
 
A new development:

The problem with the CEL and e-brake light staying on go away when I unplug the coolant temp sensor. Checked wires, they're in the right place. ???

idiot-stick 03-18-2005 06:21 PM

Re: I need some help. Strange problems during MPFI swap
 
Man, for one my ------- distro wires were backwards....or the instructions were backwords, or something. still trying to figure everything out but it pretty much idles now. Went ahead and put in the 450's and switched chips for that


All times are GMT -5. The time now is 07:09 AM.


© 2024 MH Sub I, LLC dba Internet Brands