fuel pump not working!!!

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john buck

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ok i jus installed a new motor and now i am not getting any fuel to the fuel rail... the pressure releif valve has no pressure on it...can someone tell me where the fuel pump relay is? or does it even have one? or wat wires may have something to do with the fuel pump that i wud have forgot to hook up when swapping motors?

any help is greatly appreciated....thanks john
 

john buck

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ok after doin a search and findin info i looked over... i found the fpr and cleaned it with electric cleaner.. and all of a sudden it worked.. dont know wat happened to it but now it works great...
 

john buck

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ok all of a sudden the fuel pump quit again...im beginnin to think there is a short...are the relays bad to go out? the relay is the black box about 4 by 4 inches and about 15 wires or so right? or am i looking at the wrong thing?...i read somewhere that the fuel pump relay hade a "m" on it... and this is the only "m" i can find... heres a pic of wat i think the relay is...
 
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TYSHO

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That's it.

Do you hear it click when you turn the key in the "on" position? Have you checked if you're receiving power at the inertia switch in the trunk?
 

john buck

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ok.. there is no click at the module, no power at either the pump or the inertia switch...could this be a bad ircm?

about an hour earlier everything was working fine...the module clicked and the pump worked fine...could this be a fuse? and if so where wud it be located?

thanks for the help
 

TYSHO

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Slap the sh*t out of the relay box and try again. Keep slapping it hard, it may work. If it works, start looking for a new module. If nothing, you need to test pin #5 [If I recall] to see if it's even supplying the module with the power. There's also a way to supply constant power to the module by using the test port. There's a picture of the pin needing to be grounded in another post that can be found in a search. It was posted by SHOZ123 if that helps.
 
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I have a similar issue. I got done pulling an all nighter to get an engine back in, and when I turn the key to KOEO, the tach reads 500 rpm, the fuel pump doesn't kick on, and the fan constanty turns. Any suggestions at all?
 

john buck

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have u tried any of the suggestions from tysho??? i think that my problem is the IRCM, as it makes no noise and there is no power at all at the pump or inertia valve...

i wud suggest checking the fuses...i think #5 is the one... and then check for power at the fuel pump and inertia valve...

here is a link that shows how to test the fuel pump itself...
http://www.shoforum.com/showthread.php?t=69583...

hope this helps man
 
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Cool, thanks. I didn't think to check the fuses, but I'm getting ready to head over there, so I'll give it a shot. I didn't check the intertia switch, either. But the odd thing certainly is the fan and the tach. I think I may remove the wiring harness again and redo it all. Yay... I had jumped the fuel pump, and it worked. That was the first thing I did. So the fuel pump and its connections are good.
 

92inPA

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The "M" box was used on all SHOs from 89 to 92 and the mtx 93 as well. The 94 & 95 mtx had a "D" box and all atx SHOs have a "J" box. I have heard that all mtx boxes (M & D) are interchangable, but have not personally tried a D in an earlier car.

From 89 - 91 this box was called an ICRM. From 92 & up is was referred to as a CCRM. Two names for the same thing. This box has the relays to control the fuel pump, AC and cooling fans. Russ at RCM Automotive likely has some used ones. Give him a try......

http://home.earthlink.net/~rcm_automotive/index.html


Good luck.
 

TYSHO

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92inPA said:
The "M" box was used on all SHOs from 89 to 92 and the mtx 93 as well. The 94 & 95 mtx had a "D" box and all atx SHOs have a "J" box. I have heard that all mtx boxes (M & D) are interchangable, but have not personally tried a D in an earlier car.

The "D" also works in the ATX.
 

artsho

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Here's how to diagnose the Fuel pump (FP) electrical circuit. Color codes, circuit description, etc apply to the 89 SHO.

NOTE: The 89 uses a circuit that provides 2 different voltages to the FP (according to the published documents I have available). At idle, power is supplied via a dropping resistor mounted at the top center of the firewall and a relay in the ICM. At higher engine speeds, the ECA energizes another relay in the ICM which bypasses the dropping resistor and applies full battery voltage to the FP. Other years do not
appear to use this feature, but the 90 and 91 ICM schematics still show the extra relays with no external resistor. It's up to you to figure it out.

1. Ground the FP test point on the EEC-IV connector. See the EEC self-test section of the FAQs at http://www.shotimes.com/SHO3eeccodes.html All voltage readings are referenced to a good chassis ground, unless otherwise specified. This activates the IDLE FP Relay.

2. Fuel pump SHOULD be running. If not, go to Step 3.

3. Measure at pin 5 of the ICM (PK/BK)to ground. You should measure partial battery voltage (I'll measure mine tomorrow). If so, go to step 6.

If reading is full battery voltage, there is an open circuit in the load side - Inertia switch, or FP. Go to step 4.

If reading is 0 volts, GO TO STEP 5.

4. Check inertia switch, reset as needed. Measure voltage on both leads. A good switch will have the same voltage on both leads as measured in step 3 above. If not, jumper across the switch and see if the FP runs. If so, replace the switch. Measure the voltage at the FP terminals. If you measure the same voltage at the input and the ground is good (verify it), replace the FP. If the voltage is lost at some point, you have an open circuit between that point and the previous point that did have voltage.

5. Measure ICM pin 10. If reading is full battery voltage, the FP relay in the ICM is bad. Replace or repair ICM. If reading is 0 volts, check the voltages on both leads of dropping resistor. If the readings are both 0 volts, there is an open circuit between the reistor and Fuse Link J. If one lead of
the resistor measures 0 volts and the other side reads battery voltage, the resistor is open. You can temporarily jump the resistor to see if the pump will run.

6. The FP should be running at "idle" speed. Listen carefully or have an assistant help.
 

projectSHO89

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artsho said:
Here's how to diagnose the Fuel pump (FP) electrical circuit. Color codes, circuit description, etc apply to the 89 SHO.

NOTE: The 89 uses a circuit that provides 2 different voltages to the FP (according to the published documents I have available). At idle, power is supplied via a dropping resistor mounted at the top center of the firewall and a relay in the ICM. At higher engine speeds, the ECA energizes another relay in the ICM which bypasses the dropping resistor and applies full battery voltage to the FP. Other years do not
appear to use this feature, but the 90 and 91 ICM schematics still show the extra relays with no external resistor. It's up to you to figure it out.

1. Ground the FP test point on the EEC-IV connector. See the EEC self-test section of the FAQs at http://www.shotimes.com/SHO3eeccodes.html All voltage readings are referenced to a good chassis ground, unless otherwise specified. This activates the IDLE FP Relay.

2. Fuel pump SHOULD be running. If not, go to Step 3.

3. Measure at pin 5 of the ICM (PK/BK)to ground. You should measure partial battery voltage (I'll measure mine tomorrow). If so, go to step 6.

If reading is full battery voltage, there is an open circuit in the load side - Inertia switch, or FP. Go to step 4.

If reading is 0 volts, GO TO STEP 5.

4. Check inertia switch, reset as needed. Measure voltage on both leads. A good switch will have the same voltage on both leads as measured in step 3 above. If not, jumper across the switch and see if the FP runs. If so, replace the switch. Measure the voltage at the FP terminals. If you measure the same voltage at the input and the ground is good (verify it), replace the FP. If the voltage is lost at some point, you have an open circuit between that point and the previous point that did have voltage.

5. Measure ICM pin 10. If reading is full battery voltage, the FP relay in the ICM is bad. Replace or repair ICM. If reading is 0 volts, check the voltages on both leads of dropping resistor. If the readings are both 0 volts, there is an open circuit between the reistor and Fuse Link J. If one lead of
the resistor measures 0 volts and the other side reads battery voltage, the resistor is open. You can temporarily jump the resistor to see if the pump will run.

6. The FP should be running at "idle" speed. Listen carefully or have an assistant help.


It would be nice if you gave appropriate attribution since this isn't your work....
 

artsho

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What is your problem.........That is your contribution to this persons problem.......Is this a forum for the SHO or english class....
 

projectSHO89

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artsho said:
What is your problem.........That is your contribution to this persons problem.......Is this a forum for the SHO or english class....

My "problem" is that you are posting this as if you wrote it. You did not. I wrote and posted it several years ago in this forum. It has been made available here and elsewhere with my knowledge amd permission.

Taking credit for (or failing to give credit) for another's work - mine, in this case, is quite unseemly and you should be embarrased by your behavior in posting this as if it were your own work.

This has nothing to do with English class and you should know better.

Steve
 
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St Louis SHO

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I'm with you Steve. I am an L1 cert ASE tech, and It is hard to do a writeup let-alone diagnose an eec-IV vehicle. Thanks for that post it makes guys like me feel better.

James
 

artsho

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Are you going to help this person or not ?.....L1 cert ASE tech......WOW! And all I have is a degree in engineering.
 

projectSHO89

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artsho said:
Are you going to help this person or not ?.....L1 cert ASE tech......WOW! And all I have is a degree in engineering.

Evidently, the engineering curriculum you followed did not include any character development which should have been introduced to you and reinforced by your parents or guardians.

I sincerely hope that your attitude is not an indicator of how you obtained your professional credentials or how you service your professional clients or your employer.

The original poster has plenty of information already presented. Until he has the opportunity to provide feedback, he is in need of nothing additional.
 
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artsho

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Character Development ....... This forum is a place for SHO enthusiast to seek / find help. Which is what I was doing......Trying to help.......As far as yourself.....You appear to be on a ego trip......Were you neglected as a child......Have a problem with self esteem..... Your a Moderator for this forum........You need to spend more time helping and less time on insulting people.....As for my parents .....I'd advice you to watch what you say.....I don't know about St. Louis, MO but in New York we take comments about our parents seriously......Watch yourself……
 

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