Greetings,

I've got a problem in that my car stopped running this weekend on the highway after a hard run testing my new Truleo headers. In searching the forums I have determined that it's probably in need of a new ICM.
After I got the car towed home, it would start, but not run for more than a few seconds. Today I went to try and start the car, but did not hear the fuel pump 'prime', and as such now the car will crank, but not start.

My question is - could it be the relay, or do I need a new pump? I've read here of faulty fuel pump relays and hope that is all it may need, but I don't know where the relay is located, or how to check it?

Any insights and suggestions would be greatly appreciated.

Thanks.

Paul

Attached to the firewall near the air filter housing... the AC and fuel pump relays are on the same bracket... I am not sure what the third one pictured is.



Put your fingers on the relay and have someone turn on the ignition, if you feel/hear it click, it's probably not the relay.

[This message has been edited by carbon (edited 07-26-2012).]

Thank you very much for such an excellent descriptive and concise response!

Cheers.

Follow-up: I've switched over the fuel pump relay to the AC relay and checked the fuse (it's good), but there is still no 'priming' sound of the fuel pump and thus no start of the car.

Does this mean I need a relay replacement, or a fuel pump replacement?

Thanks for any and all help.

Paul

[This message has been edited by I FAR I (edited 07-26-2012).]

Quickest way:

Jumper the fuel pump pin on the ALDL plug (pin G to 12v - bottom left most pin when looking at it) - if the pump turns on, possibly a bad relay, if it doesn't bad pump.

Edit:

Do the above test - if the pump comes on then you need to start checking voltages at the relay since you already tried a different relay.

BTW - of note, the car will start if the relay is bad (and the pump is good) by cranking it with the starter until the oil pressure builds up (the oil pressure switch bypasses the relay) - not the best thing to do all the time (hard on the starter), but at least it won't leave you stranded.

[This message has been edited by Mickey_Moose (edited 07-26-2012).]

@MM...thanks for the heads up!

If there is no pump 'priming or relay click sound', like I used to always hear, is that indicative of a bad relay, or pump tho?

Plus, I was wondering if a faulty ICM could be the root of my problem and maybe not a faulty puel pump or relay.

Thoughts or Opinions?

Also folks, I've got a Vortech G9 supercharger on the car and was wondering if the stock fuel pump will be adequate or should it be upgraded and if so, to what?

Cheers.

[This message has been edited by I FAR I (edited 07-26-2012).]

Nothing to do with the ICM.

jumper the ALDL plug first and then go from there - there is no point in wondering what if or making it more complicated than it is.

The ALDL pin drives the fuel pump directly, if it doesn't turn on, you have an issue with the pump.

No point is wasting anytime checking anything else until you have done this simple check.

*IF* you want to check the relay side, disconnect the plug that feed the fuel pump center of engine bay near the firewall (C502) and measure if there is a voltage on the Tan/White wire (pin C) to ground with the key on. If you are getting battery voltage, relay is good. If not, check if you have power on the Orange/Black (pin D) wire at the relay. The Green/White wire (pin A) is the power feed from the relay - the Black/White (pin C) wire is ground).

You can also download the factory service manual from Fiero News website - it probably has a step by step proceedure on how to troubleshoot the fuel system electrical side.

[This message has been edited by Mickey_Moose (edited 07-26-2012).]

OK, is that pin G closest to driver's side or passenger side on the bottom of the ALDL and what should I use as a 12v connector?

Thanks

[This message has been edited by I FAR I (edited 07-26-2012).]

Passenger, bottom
\

Thank you!

quote Originally posted by Mickey_Moose: Quickest way: Jumper the fuel pump pin on the ALDL plug (pin G to 12v - bottom left most pin when looking at it) - if the pump turns on, possibly a bad relay, if it doesn't bad pump. Edit: Do the above test - if the pump comes on then you need to start checking voltages at the relay since you already tried a different relay. BTW - of note, the car will start if the relay is bad (and the pump is good) by cranking it with the starter until the oil pressure builds up (the oil pressure switch bypasses the relay) - not the best thing to do all the time (hard on the starter), but at least it won't leave you stranded.

Mickey_Moose, or anyone else who may know...How do I 'jumper' the fuel pump pin G? I appreciate the help, but am unclear on how I get a 12v to do as you state. As you can surmise, I'm not too experienced with automobile, electrics or mechanicals, but, guys like you are really helping me to learn.
I hope to upgrade my fuel pump regardless, but would like to know how to perform the above mentioned procedure correctly.

Thanks

quote Originally posted by I FAR I: Mickey_Moose, or anyone else who may know...How do I 'jumper' the fuel pump pin G?

Its easy, actually. Just a few inches away from the ALDL, is the cigarette lighter. Just run a jumper from the "hot" side of the lighter terminal to the Pin G. If I remember right, I just used the same bent paperclip I had in my ashtray from the last time I checked for code. Once you connect the 12V from the lighter to Pin G, you'll either hear the pump run - or not.

Cool...Thanks!

Getting at the cig light 12v is not easy with the console in place using a paper clip.

12v on the cig lighter is the center post on the inside bottom of the cig housing - I personally would not recommend trying to get power from that point (can be done using some stiff wire, but you have to make sure you don't touch the sides of the housing with any bare parts of that wire, plus it has to be long enough to reach the ALDL pin). If you remove the console, it is the orange wire that is plugged into the rar of the cig lighter.

Do you have some wire about 5-6 feet long? If so you could strip the one end and twist the strands togther on both ends (ideally solder them if you have a soldering iron to make them stiff). Stick the one end between the tabs on the ALDL pin (I might be tough without soldering but it can be - just make sure you have no stray strands touching the pin beside it. Once done take the other end over to the fuse box under the dash to the left of the steering wheel. Locate 1 of the terminal marked BAT and tough the wire to that. That is a 12v feed - if not one that is easy to get at you can use one of the ones marked IGM, but the key has to be on.

If you wish to use the cig lighter you need to remove the console.


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An alternate method is to use a voltage meter to measure the voltage on the ALDL pin, hook up your meter and turn the key on and see if you get 12v, but remember you only have a few seconds to see this. If there is power there and the pump is not on, the pump is dead (and the relay and everything else is ok since it is trying to turn the pump on). This method doesn't directly drive the pump as jumping it, but relies on the rest of the car to turn on the pump - plus if your meter is slow to respond, not really the best method - a test light could also be used instead of a meter.


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As for your supercharger question, I can't really help you there - but you may need bigger injectors. The fuel pump is regulated, so putting in a bigger pump is not help much and you may have to change out the regulator - but best if you start a new thread asking other about that as there are some people on here that have WAY more experince in that area.

[This message has been edited by Mickey_Moose (edited 07-27-2012).]

quote Originally posted by Mickey_Moose: If you wish to use the cig lighter you need to remove the console.

Its been awhile - I think I removed the screws that mount the lighter to the console.