wiring in a 3.0....need help

[fa SHO]

hi guys

im wiring up the 3.0 ecu and mtx harness to my 1991 mx6 gt. im using the mx6 body harness to power the body, lights etc starter, cooling fan relay, and fuel pump are all functional. fuel shoots out the valve on the rail with plenty of juice. all the grounds i have found off the engine harness have been grounded. i also ran grounds to intake manifold, lower DIS bolts, and tranny

right now. i have pin 1 hot all times, 37 + 57 when the car is on and in start. pins 40 and 60 are grounded to chassis

do any of these grounds or power wires also need to be hooked up to the wiring harness, or just the ecu?

from what i understand, i also need to run 12v while starting to the DIS to pin 6. well, there is no wire on pin 6. its actually plugged. should i still feed that pin somehow?

is there anything else i am missing? any help would be appreciated. thanks

 

[mrecoolgar]

Duuuh.
I can't offer any help at this time.
I may be researching the wiring this winter for my RX7 project.
OffRoadSho will probably help you soon.

 

[black92]

You may have seen this thread, if not I hope it helps.
http://www.shoforum.com/showthread.php?t=115598

 

[probe_racer]

check my post

http://www.shoforum.com/showthread.php?t=108928

im on the process of putting a 3.0 SHO on my 91 lx probe and the wiring most likely is similar when it comes to powering up the ecu.

did you notch the frame to make engine fit or how did you fit the engine??

 

[fa SHO]

thanks for the links

im actually familiar with both threads. i talked to bob90lx who got his probe to run and followed what he recommended

and yes i notched the frame in, and cut some out of the front mount to fit the engine and close the hood.

the coolant sensor on the thermostat housing isnt hooked up, and i still dont have a maf. would that stop it from running? im not familiar with this ignition system. i took pictures of the harnesses, because there are quite a few empty plugs. i dont have a manual and havent found any sho engines in the yard to reference.

end of the harness that goes under intake manifold. do i connect it with the other part of the engine harness?

heres one end of this harness, the other side has the ccrm and 1 or two other plugs

the whole mess.....lol

she's just waiting to run

 

[kevinspann]

Yes that harness definitely needs to be connected or it will never run. Not all of the plugs in it will be used, but all of those round 8pin will. They make it run, lol.

 

[fa SHO]

yea i had them connected originally but disconnected them to see if it would start up.

does the ccrm need to be plugged in? im not sure but it sounds like some wires need to be jumpered to bypass the ccrm, or it needs to be plugged in.... that seems to be the only thing different between what bob did and what im doing

 

[kevinspann]

Yes, for sure.

It should start without a MAF and temp sensor (there is one for the gauge, and one for the PCM).

 

[Off Road SHO]

I believe that without the Air Flow sensor, the PCM thinks there is no air flow so it won't pulse the injectors.

The CCRM is a box of relays that sends current or grounds to things that need it such as the cooling fans, fuel pump and I believe the PCM. Do you have the EVTM diagrams?

Tom

 

[fa SHO]

i dont have the evtm diagrams. ive been looking at other like threads and a ccrm diagram.

would it be possible for me to jumper pin 8 to 24 on the harness at the ccrm to power the pcm?

unfortunately when i bought my sho from rubydist, i guess we didnt exchange the ccrm. i dunno if he would have it, but i dont know if i need it either? everything works with the car i just need the engine to run

maf is on the way. should be here early next week

 

[Off Road SHO]

The 3.0 SHO CCRM has 5 power inputs from the engine compartment fuse block; they are on pins 3 & 4 for the Cooling fans, pin 13 for the PCM powering relay enable, and on pins 8 & 12 for fuel pump and PCM powering. So you could theoretically use any of 3,4,8 and 12 to power up pins 37 and 57, but then they would be hot at all times. It would be better to use the ignition switched pin 13 to send the required 12 volts in start and run, through a relay to power up the PCM.

Also, pin 20 of the PCM need to be grounded.

Tom

 

[probe_racer]

i will look through by notes and i will post them to show how i wired mine, you are going to have to modify the harness quite a bit.

Bob and I went through his build together and i got behind on mine cause of moneys... (that is why i dont make fun of canada anymore their economy is good)

if your 3.0 wiring is from a 91-92 it should be same as mine

keep an eye out i will post my notes on my post that should help.

 

[fa SHO]

ok after checking into the ccrm i guess im barking up the wrong tree...i have an operational fuel pump during run and start. i have an operational cooling fan relay. the starter and alternator are hooked up fine as well. i dont need it for anything

i have power during run and start to pins 37 and 57 (lines are tied together at a single source)
i have power always to pin 1 (single line 30 amp fuse)

i have pins 20, 40, 60 grounded to the chassis. do i need to ground the engine harness of those lines as well?

if all is well i guess ill just cross my fingers and hope the maf gets it running. i know on systems like megasquirt you must have a coolant temp and map input for it to calculate required fuel

 

[Phoenix]

CCRM pinouts: http://www.shospeed.com/pics/SHOCCRM.pdf

 

[Shovert]

I would change 2 of the grounds. I would have to check and find out which one's 2 of the wires go directly to the same bolt as the main body ground of the battery cable. I know Ford did it to prevent [interference??]. I know on my project and my Ford 2.3 turbo swap they way it needs to be. One of the pins grounds near the computer. Maurice.

 

[fa SHO]

i have a ground that comes immediately off the harness which i grounded to the firewall

there was also 2 grounds that i bolted down by the injectors

i tested for 12v across the wiring harness. i was able to find 12v at all solid red wires that i found hooked into sensors, like what appears to be the maf and iac connections

i tested for 12v on the red/green wiring that is on the cam sensor and on the 1st dis pin. both of them are only reading something like 0.25 volts. so i think thats where my problem is......unfortunately i just dont know where im going wrong in the wiring to get that power there

 

[Shovert]

Here is a example of the wiring diagram. 3.0 unsure which one because of year model. Maurice
http://www.autozone.com/autozone/repairguides/WIRING-DIAGRAMS/WIRING-DIAGRAMS/_/P-0900c152802798c9
Edit figure 20 or 24
Another source.
http://www.yunost.ru/docs/Chilton-Ford/by-parts/06-chassis electrical/12.pdf

 

[fa SHO]

thanks a lot so far for the help guys.

it looks like the red/green gets power somewhere from the ignition switch....im not sure what part of the harness that is suppose to happen at. im not the best with wiring diagrams but it looks like pin 13 of the ccrm puts the power through from the ignition switch to that red/green wire. it looks like i could add power anywhere and it will get to all the sensors. ill see if that helps get her going

ive noticed my voltage to pcm when cranking goes from 12 to 9v. is that natural, or do i have too much juice coming from that circuit?

edit: also i just noticed on those two wiring diagrams 89-90 wiring harness vs 90-91. the red/light blue wire doesnt hook into the DIS (ignition control module on diagram) i think its safe to assume i have the 89-90.....it would seem that i dont need 12v starting at DIS pin 6.....but would i need a 12v starting signal to somewhere else instead?


edit again: i have spark!!! i ran 12v from the red wire off the ccrm (pin 24) to pin 13. i do not smell any fuel at all though even though the rail is pressured, im pretty certain the injectors are not firing....i still have no maf and ect sensors

 

[Shovert]

12vdc from starting signal. I think is larger wire from wire to starter. I got a large wire from there to my engine harness. Do you have a ccrm module. I know wiring to fuel pump comes from there. Do you have 12vdc to fuel pump? You could temporary put 12vdc to it and then try starting. If starts then we can figure that wiring out. Maurice

 

[fa SHO]

sorry for last post. probably not easy to read....

the fuel pump works. there is pressure at schreader on rail

i have spark


i dont smell any fuel in the engine, though i have 12v to maf and injector circuit. it could be because i am missing sensors