Fuel Delivery (or lack thereof)

[ottathom]

Hello,

I am wondering if I can call upon the collective wisdom of the SHO Forum to construct a plan of attack to diagnose a fuel delivery problem in my 1989 SHO. I bought the SHO about a year ago with the intention of pulling the engine to use in another project. I have never actually had it running, though I'm pretty sure it will. The individual I bought it from put a hose on a propane tank and stuck the other end in the intake and the SHO started and idled. He apparently fancied himself an electronics expert because he cracked open the box of relays that sits on top of the radiator and replaced a few relays with parts from Radio Shack. Not trusting his soldering skill I replaced the unit with a new one from NAPA. Still no joy. I don't hear any clicking or pump running when I turn the key. I understand from reading other posts that there is another fuel relay somewhere in the trunk area. Is this so? Where is it located and how does one test it? I am familiar with the use of a multi-meter. What else should I check before I attempt to cut an access panel to the fuel pump?

Thanks for any help,

Tom Ottaway

 

[luigisho]

Tom, there is an inertia **** switch in the trunk. Look for a red button on a module in the trunk around the quarterpanel. This kills power to the pump during an impact.

 

[luigisho]

Check for power going to and from the inertia **** switch before going to the tank and the pump.

 

[itwonder]

Tom, double check that NAPA gave you the correct CCRM. It should have a label with a large letter "M" printed on it. That is a "M" code CCRM, used in '89-93 MTX SHO.

 

[TYSHO]

I've made quite a few post relating to the fuel system powering, as of lately.

If you're not receiving any type of clicking from the CCRM, you most likely are not getting any power to the CCRM. This will most likely be a PCM problem, but you can pull out your tester and check the wires [search this up, also] and hope both CCRM's you've had were complete crap. You can also hook the ECC self test up with a paper clip, which will kick the radiator fan on quickly [power is sent through the CCRM]. If the fan does not kick on, the CCRM is either non-functioning or you're looking at the PCM. It's rare that something else is the problem, like the wiring to the CCRM.

If you want to check the inertia switch in the trunk [which has no relation as to why you are not receiving any clicks from the CCRM], you need to disconnect it and use a cheap 12-volt light test. When you turn the key to the run position, you will only receive power to the wire [1 of the 2] for 1-2 seconds before it shuts off. However, if you have the key turned to the furthest point, as in starting the engine, the wire will stay powered until you release the key from this cranking position. When the key is turned to the "on" position, the relays in the CCRM will click, just as they will click after those 1-2 seconds when the power is cut off. If you check this switch, it will not be receiving power according to the details you have posted. This also means your fuel pump will not receive power, so there's no need to replace the pump just yet.

 

[ottathom]

Thanks for the speedy responses. I've had to wait for stormy weather to clear out to get back out to the car. I have been searching the prior posts diligently, I promise. However, what is a PCM and what is a CCRM? This the part I had to replace:



It seemed like each parts supplier had a different name for it. I believe this to be a Power Control Module or PCM. Is this correct? If so, what is a CCRM and where is it?

As for the inertia **** switch, is this it?



I certainly appreciate everyone's help and patience with lack of knowledge.

Tom Ottaway

 

[luigisho]

That is the inertia switch to the fuel pump in the trunk. The ccrm is the 1st picture and looks different from the oem tag. Not sure what aftermarket stickers look like and if it's the correct one.

PCM=ECM or ECU = computer. Drop the glove box lid by pushing the sides in to release it from the track and you should see it protruding from there. There is a wiring harness on the other side of the firewall that plugs into it. THe middle of the harness has a round **** which is the end of a bolt that screws into the back of the computer to keep the plug from coming off.

 

[itwonder]

Take a look at this post. It has pretty comprehensive troubleshooting suggestions.

http://www.shoforum.com/showthread.php?t=95763