Location of Fuel Pump

[RyanSheldon]

I suspect my fuel pump is on it's way out since my '90 SE simply does not want to start on occaision. Once going, it works well, but I think the motor is having difficulty spinning up. I am trying to locate the fuel pump for replacement. Any directions on where to find it would be helpful. My manual seems a little confusing on this issue.
Thanks,
Ryan

[lotusman]

It may not be your fuel pump. They rarely go out. There are three relays in the trunk area that must close to start the pump. It took a week or so before my pump would stop and not come back on. I would wait 30 minutes or so and it would restart. It turned out with my 89 that the ECM was going out one part at a time. Is any other control situation bad? My was that the radiator fan came on as soon as I turned the key, even with the A/C off. I jumpered out the fuel pump relay and did so for a year before the ECM went out entirely. Even then it only cost me $80 to replace the box and reinsert the chip.

After opening up the trunk relay box, have some one operate the ignition key while you listen/ feel the relays. The relays should close sequentially and the pump start until it pressurizes the system, usually 2 or 3 seconds then stop until you engage the starter.

Hope this helps.

Have you changed the fuel filter and use good gas?

[cnh1990]

Fuel pump mounted in right fuel tank access.
Calvin

[RyanSheldon]

I am starting to think the fuel pump is fine, I have attached diagnostic LEDs to activate as the relays are activated. I think my ECU may need to be replaced to solve the problem correctly. Do you have a source for your $80 ECU replacement? Also, while I am in the computer, I would like to upgrade the firmware. I would like the turbo and the cooling fan to kick in sooner. Do you know who offers this upgrade? Cost?

[lotusman]

Since you found the fuel pump you know where the ECM is. Tony Grasso had a posting that had the numbers of the ECM box models in this forum. Mine is from a chevy cavalier 1988. Check to see if you have the four plug or the three plug. The four is about $125 from Auto Zone, where I got mine. On your box you will see a number, you should be able to cross reference with it.

You are talking about a chip reprogram that will cost from what I read in this forum is about $600 and time to send it out. Tony and Sanj do this kind of thing.

Are all your relays clicking closed, lighting the LEDs?

[RyanSheldon]

I have connected the LEDs to the coil side of the relays, this will allow me to test to see if the ECM is sending the signal to the relay. Later, I will rewire to the output side of the relay to test for actual switch closures. So far, the LEDs are indicating proper operation, however, this problem only happens sometimes. Also, on occaision, the ECM skips the warm up cycle, so I will replace soon. Thanks for your help on this. -ryan

[grungex]

Hi Ryan,

I offer several firmware upgrades for the SE, starting with the S4s Mark V, to the Andy Whittaker version which has the cooling mods you describe, up to the Moto-Concept chip which also offers more boost. You may contact me at [e-mail] for more details, or visit my web site at http://turboesprit.tripod.com/index.html.

Cheers,
Sanj