No start conditions & IRCM's????

[grif]

Guys I'm a new memeber, I do not own an SHO
however I own a small repair shop and do
maintence them (I know many owners), and
have added performance upgrades for many of them.
I need some help (if anyone knows) on a no start
condition on a 1991 3.0 5spd.
I use "All Data" Diagnostics and every proceedure
I've run through points to the Intgrated Relay
Control Module that controls power to the
fuel pump circut, the maf, the injectors and
fans (to name a few). The local Ford dealer
will only help if you spend money with them to diagnose so that option is out (I don't think
they'd have a clue anyway).
Here's the deal, I diagnosed a failed IRCM, spent
the money for a new unit straight from Ford
(not a used one, not a salvaged or rebuild)
reinstalld the unit and still no go, same conditions exist.
Have ANY of you ever had this happen and or
can some one clarify what "engages" the IRCM
to turn "on" allowing power to the ECU, MAF,
Injectors, ETc. Ford doesn't know or can't
figure it out, other S.H.O. specialists I know in the So. Cal. area haven't a clue either.
I can verify I have power coming into the IRCM
at all pins on the IRCM harness connector,
but no power out, and apparently no way of
determining what does turn the module "on".
Thanks in advance for any insight..

Greg Grifka
of
Grif's Garage (Hot Rods & Kustomz)
Newport Beach, Ca.
(949)887-1399
(all are welcome to call if you feel you have relevant info)....
area have no idea

 

[autobahnsho]

I know that if the module at the end of the intake is unplugged everything can look fine but the car won't start. Other than that, I'd check the engine codes....

Good luck.

ps- I don't want to sound at all mean,
I don't know how people here will respond to you asking for "free" help.
Although we love to see SHOs maintained and still on the road, we all do work on our OWN cars. Of course a lot of people trade favors and help each other out....

So what will YOU do for the forum??

<small>[ January 30, 2004, 05:41 AM: Message edited by: autobahnsho ]</small>

 

[Rockledge]

When you turn the key to the "on" position before starting, do you hear the fuel pump priming? The ICRM has a bunch of relays in it, including the fuel pump relay.

 

[bradman]

I've had a similar problem to what you describe, on my '89. My problem is intermittent, and it manifests itself with all the symptoms of a bad IRCM, but I too have changed the IRCM with no luck. The last time this happened to me, the car just shut down at an intersection. I pulled over popped the hood and started wiggling the big connector to the EEC. Suddenly, the IRCM came back to life and all was well again.

Now, maybe it's just coincidence that I got power back when I wiggled the connector, but I doubt it. I haven't been able to get the connector off the EEC to check the connections because the shop at the dealer I bought it from (cheap) broke the bolt that holds the connector into the EEC, and it WILL NOT come off (corroded?) shrug . When I have time some day I will get that sucker off even if I have to replace the harness.

 

[projectSHO89]

Grif,

Welcome! Hope you stay awhile and add to the forum in your own ways!

The IRCM is simply a set of relays (with a few additional circuits as needed for certain functions) all contained withing a single box. It makes it easier if you think of it that way.

Items of special interest inside the IRCM are the PCM Power relay and the Fuel Pump Relay(s).

If the CEL works when the ignition is turned to RUN, the PCM power relay is probably okay.

If you can hear the fuel pump run for 1-2 seconds at the same time, the FP relay is also okay.

Also, clarify if you have a "No Crank" or a "Cranks but no Fire" condition.

Drop back to your basics: Air, Fuel, Spark, (and everything at the right time)

Air - Crack the throttle 1/4 way to see if it now fires. If co, address the Idle Air Control valve

Fuel - Does the Fuel pump prime? Can you get 36-42 psi pressure at the test port on the rail after several primes? Did the pump work at all? If you got pressure, are the injectors firing while cranking?

Spark - Connect your inductive pickup timing light to the # 1 or # 5 plug wire (they fire at the same time) and see if you get any spark. If so, is it timed correctly? (10 BTDC).

One (or more) of these tests will fail.

Let us know which one(s) and you will be asked more focused questions and offered suggestions based on your responses.

Good luck.

BTW, see the sticky post at the top of the Electrical Troubleshooting forum and get the diagrams for the car you are working on. They may be referenced in future responses.

Steve

 

[grif]

autobahnsho:
I know that if the module at the end of the intake is unplugged everything can look fine but the car won't start. Other than that, I'd check the engine codes....

Good luck.

ps- I don't want to sound at all mean,
I don't know how people here will respond to you asking for "free" help.
Although we love to see SHOs maintained and still on the road, we all do work on our OWN cars. Of course a lot of people trade favors and help each other out....

So what will YOU do for the forum??