Car won't start. How do you know when the computer is dead?

[SHOZ123]

.....

So, that would indicate the fuel pump died, correct?

No. This just confirms the relay coil is working and the clicking you hear is the contacts being pulled in. You do not know if the relay is passing power. The easiest way to check is to again ground the test pin with the key on and with the relay pulled in there should be 12V at the inertia switch in the trunk. If it has and is passing 12V then the fuel pump or the "in the tank" wiring is suspect.

 

[matt621]

Okay, I got a guy working on it for me and he says the IRCM is bad becaause it's not sending power to the computer. (even tho the fuel relay does work)

So where can I find an IRCM?

I'm told the dealer doesn't sell them anymore..?

 

[SHOZ123]

NAPA sells rebuilt ones. So does Rock Auto.

 

[matt621]

Thanks for the offer, but I think the computer might be okay.

Yes, right after it died I did check the schrader valve and got a big squirt of fuel. A few days later I check it again and it had none.

The mechanic hardwired the fuel pump and it was fine. 50psi he said. (is that correct?)

I found the part numbers for the IRCM:

AC Delco

ACDELCO Part # F1792A (supposed to be new)
RELAY,BRK CONT MDL F1DF-BA **#89057549}

STANDARD MOTOR PRODUCTS Part # RCM22 (rebuilt)

NAPA AR 763. (supposed to be new)

No one in town has any of them. Having to order and shipped in.
The napa was the most expensive, but it didnt' have a core charge and is supposed to be new.

 

[matt621]

UPDATE:

The mechcanic I'm having work on the car found another ICRM (rebuilt.) It lasted about 3 days. The one we got from Napa (supposed to be new) lasted about 3 days. The problem is that on the original ford one, both the Fuel relay and the ECM relay died. On the 1st replacement box, the fuel pump relay died, but the ECM relay continued to work. On the Napa one, the ECM relay died, but the fuel pump relay continued to work.

We've checked for shorts and traced back the wiring harness and all looks fine. Check resistance thru the various circuits and all appears to be good. We've got another box from Napa coming... will see what happens with this one.

But this is a very discouraging issue to have such a great car have such a weak link, and ford no longer offers the part...

Does anyone have anything else to add that should be checked? Does anyone know of a source for a Ford NOS box? Has anyone tried to just replace the box with individual relays?

 

[93ATXChris]

Hey i'm having the same problems with my car. Koeo isn't working and fuel pump isn't getting power.

Please keep us updated

 

[matt621]

Well the 2nd napa box arrived and now 1 day later it's dead. There has to be somethign causing this. I would guess a short or overload on something. I think we can rule out the fuel pump since that was changed. Seems unlikely the new one would be doing exactly what the old one was doing. So that leaves what?

There has to be something someplace that is causing this. Has anyone had this many problems with ICRM going out? I can't help but think the IRCM is not the root of the problem but something else in the car going bad that causes it to die. Not just my car but others as well.

That thing controls a high and low on the fuel pump, ECM, Fan, AC, and somethign called an HEDF relay... but the mechanic says it's always the fuel and/or ecm that dies.

 

[Bluestreak]

I'm having the same problem. I have a 92 SHO MTX. What happens in mine is that they pin 12 and 10 keep melting onthe board. I have power at the plug for the IRCM and have found all the wires that I checked so far to have good Ohms/ ground/ or power. Can a ECm take out a IRCM??

 

[Bluestreak]

BUMB. Matt ; where are you at??

 

[matt621]

Arizona

So far this thing is really driving me nuts.

I found different diagrams for this control box/model. The diagrams on that russian site, I believe are for regular taurus. Not SHO.

Here is the diagram for the SHO I found on alldata:

http://trueblueoval.com/sho/1992-SHO-IRCM-Wiring-Diagram.gif

it shows 2 fuel relays, but all the other diagrams I've seen show only 1. I think that is the problem. I think these aftermarket people are sending regular taurus IRCMs which only have one (probably low) fuel relay. The SHO probably has some extra fuel pump relay for high output or something and that's what is causing these aftermarket ones to die.

 

[Bluestreak]

well keep us informed. I'll keep you guys informed on my car also.

 

[SHOZ123]

The '92 Ford CD only shows one relay. On my '93 I get the low fuel pump relay code but it is non-existent.

 

[matt621]

UPDATE:

the module the mechanic has been using has been a plain ford taurus model. It's a "Four Seasons" PN 37512, which is NOT the correct part. So that would explain why it fails.

It still does not explain why the Napa parts have failed since I ordered it myself and made sure the guy knew it was for the SHO and I believe it's the right part since it had to be special ordered.

I'm still looking....

 

[Bluestreak]

Read the end of this thread. THis is my thread on my 92 MTX.

http://www.shoforum.com/showthread.php?t=48408

 

[93ATXChris]

Yeah i'm having a heck of a time finding an IRCM

On the first page someone posted an AC DELCO part number, but i called AC DELCO and the part isn't in production.

I called NAPA and told them i needed a relay control module, but they couldn't seem to locate one...But i did give them the part number NAPA AR 763 from the original poster and they have it coming from Virginia.

Matt621 where did you come up with that part number? I called Napa, told them that part number and asked what car its for but they didn't know

 

[Bluestreak]

Why don't you post an add in the want section on this forum. I got 2 IRCMS in 2 days.

 

[matt621]

UPDATE:

I ordered the AC Delco unit from rockauto, only to be told a week later, it's been discontinued. So that solution is now a dead end.

The napa boxes died after a few days.
The "4 seasons" boxes died after a few days. However, they it was confirmed they sent the wrong part. They sent the one for a regular taurus. They said they had one for the SHO, but it's special order.... I decided to wait and try to find a ford one. I'll bet that if I did order it, it'd be disco'd too.

So we are back to finding a ford unit. Supposedly one is coming... still waiting on it.

 

[matt621]

Yeah i'm having a heck of a time finding an IRCM

On the first page someone posted an AC DELCO part number, but i called AC DELCO and the part isn't in production.

I called NAPA and told them i needed a relay control module, but they couldn't seem to locate one...But i did give them the part number NAPA AR 763 from the original poster and they have it coming from Virginia.

Matt621 where did you come up with that part number? I called Napa, told them that part number and asked what car its for but they didn't know

Yes, now i'm told the AC delco part is now disco'd.

The napa part number I got from a napa store. He didn't have any trouble finding it, but I doubt it'll work cause the 2 we got both died.

 

[Bluestreak]

DId you try to find one out of someone elses junked car?

 

[SHOZ123]

In '98 Ford finally got away from the IRCM/CCRM in favor on a central relay box with replaceable relays. One of the best things they ever did. You could probably find one on eBay from a '98 or newer Ford product.