[BrendanW0214]

First off, I apologize if this is the wrong forum, but hi I'm a new guy here. I bought my first F car three months ago which is a 2000 Firebird. It's nothing exciting, just a 3800 automatic. It has been a very trouble free car which I quite like however for the past week and some change I have had a strange issue with the fuel pump. Before I continue I must add that the car does have a new fuel pump and filter which were installed by the previous owner prior to me buying it (I do have the papers that prove that). So anyway, the issue is after driving it for a couple hours or so, I will go to start the car and the fuel pump will not make any noise and it will not start. I first thought it was the fuel pump relay, so I replaced that and it worked file until the next day where the same thing happened again. After letting it sit it somehow started on its own. Fast forward a few more days and a three hour round drive later, I go to start the car, same thing! I must add that while it was running I had zero signs of anything being wrong, and the SES light was not illuminated as well. As far as the temperature was concerned, I would wager it was probably in the mid 90s and I was driving in daylight too. I ruled out fuses and the relay as I switched those, and I don't really think it could be the pump because if it was bad I don't imagine it would work at all and the new one only has 3000 miles on it. I've tried to research what's going on but came up empty handed because although I thought I fixed it, it's still persistent. Could someone help me figure out what on earth is going on? Thanks in advance.

 

[Injuneer]

Do you know the brand of the new fuel pump? There are numerous Chinese counterfeit fuel pumps on the market. Possible the pump is heat soaking and temporarily inoperative until it cools down. There should be a fuel pump prime connector under the hood, possibly near the PCM. That allows you to apply 12 volts (almost) directly to the pump, to test whether it’s operating.

The location of the prime connector could be verified by looking at the factory service manual. Should be a free download of the 2000 manual here:

MediaFire

MediaFire is a simple to use free service that lets you put all your photos, documents, music, and video in a single place so you can access them anywhere and share them everywhere.

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[1993TransAm]

I think I already know the answer to this question, but here goes: Did the car crank normally during the no-start condition?

 

[BrendanW0214]

I think I already know the answer to this question, but here goes: Did the car crank normally during the no-start condition?

Yes sir. It would try to start but ultimately wouldn't unless left sitting for a bit. Frankly it acted like what happened when my other car's (a 1988 Mustang) fuel pump died, although if the pump was truly dead it wouldn't fire up after sitting for about 20-30 minutes, at least I would not assume so. Admittedly GMs are still a learning experience as before my Firebird I had nothing but Fords, but hey we all learn new things every day.

Do you know the brand of the new fuel pump? There are numerous Chinese counterfeit fuel pumps on the market. Possible the pump is heat soaking and temporarily inoperative until it cools down. There should be a fuel pump prime connector under the hood, possibly near the PCM. That allows you to apply 12 volts (almost) directly to the pump, to test whether it’s operating.

The location of the prime connector could be verified by looking at the factory service manual. Should be a free download of the 2000 manual here:

MediaFire

MediaFire is a simple to use free service that lets you put all your photos, documents, music, and video in a single place so you can access them anywhere and share them everywhere.

www.mediafire.com

Thanks for the link! I downloaded it and will check it out and see what I can do. I ran the part number for the pump on the work order from March of this year and the number came back to a Delphi pump. To be exact the number was an FG0102.

 

[1993TransAm]

I'm curious to know if the previous owner of the vehicle was experiencing a similar condition and replaced the fuel pump and filter in an effort to remedy the situation. It seems unlikely to me, but you might also rule out a wiring issue.

I bought a 1990 Beretta from someone who replaced the ignition control module, fuel pump, fuel filter (and possibly other parts I can't remember) in an attempt to fix a stalling condition before he sold it to me. What he missed was a bad injector causing the problem, probably because he didn't do a thorough job of diagnosing the problem.

 

[BrendanW0214]

I'm curious to know if the previous owner of the vehicle was experiencing a similar condition and replaced the fuel pump and filter in an effort to remedy the situation. It seems unlikely to me, but you might also rule out a wiring issue.

I bought a 1990 Beretta from someone who replaced the ignition control module, fuel pump, fuel filter (and possibly other parts I can't remember) in an attempt to fix a stalling condition before he sold it to me. What he missed was a bad injector causing the problem, probably because he didn't do a thorough job of diagnosing the problem.

I have the prior owner's contact info, so I may very well ask her about it (before me, the car was one owner and owned by a lady funnily enough) and report back with my findings.

 

[BrendanW0214]

Okay so I spoke to the previous owner, and she did experience this issue once before in about 2005, however then the car was still running its original fuel pump and had approximately 70k on it (It's at 110K now). She informed me what fixed it was a new relay and from then on she did not have any trouble. I have been doing some light driving (nothing over a few hours) and have not had this issue come back, however I'm not holding my breath on it being solved. I did also notice it seems more likely do to this when the car has under half a tank of gas in it which I find strange. I'm reporting back to you all what I heard. I did also swap relays from a cheapo aftermarket CarQuest one to a proper OEM one (ACDelco if anyone is curious) so I am hoping that at least helps. If this persists then what other areas should I look into? I did read that possibly the OPSU may also have something to do with this? It's easy to get to and the one in the car is probably original so if it is relevant perhaps I will replace it and see if it helps any.

 

[1993TransAm]

Did the part number you replaced end in a "P," by chance? (I do believe that Advance Auto Parts simply re-branded their BWD line as Carquest.)

 

[BrendanW0214]

Did the part number you replaced end in a "P," by chance? (I do believe that Advance Auto Parts simply re-branded their BWD line as Carquest.)

I put in a Carquest RAA1236 relay, and when it acted up for the second time this past Tuesday, I pulled it and swapped it with an ACDelco D1786C relay. Are these the numbers you were inquiring about? If not then I can check the old parts and see what is on them. Since dropping in the ACDelco one I've had no problems with it doing this, but admittedly I have only driven short distances (the longest was an hour round trip to visit someone in the hospital on Wednesday) and it hasn't been sunny and really hot out, so I'm not holding my breath on the problem being fixed.

 

[BrendanW0214]

So, as an update: The car did the same thing this past Saturday and I dropped it off at my mechanic to let him have a look at it. He was not able to recreate the issue, however he is still going to root around and see if he can figure out what's what. He's a good honest guy I trust completely. I was talking to a friend about what is happening, and he suggested that a crankshaft position sensor or possibly even the ignition control module could be going out. Is he onto something, or is there really any truth to that? My dad (who has been wrenching ever since he could walk essentially) also brought up that there could be an actual control module for the fuel pump that could be going bad, which I have honestly never heard of. Does such a thing exist in a 3800 F body, and if it does where would it be located?

 

[1993TransAm]

To answer your last question: There is no separate fuel pump control module in your vehicle.

 

[BrendanW0214]

To answer your last question: There is no separate fuel pump control module in your vehicle.

Gotcha. One more thing to cross off the list then.

 

[Injuneer]

When the crankshaft position sensor is “going out” it's going to set a code. I don't know enough about the V6’s ICM to know what codes it sets. You could find this out by looking in the factory service manual. Have you downloaded a free copy?

There are two critical components that control the fuel pump. The PCM decides when to turn the pump on, based on two factors - 1) are there any codes set that prevent the PCM from turning on the pump; and 2) did the PASS-Key II (VATS) system, incorporated in the body control module (BCM) recognize the resistor in the ignition key and send the “fuel enable” signal to the PCM. If the PCM is not receiving the “fuel enable“ signal from the BCM, it sets a code and will not start the pump. Would also set a code in the BCM. If the starter is cranking the engine, the key resistor has been recognized. The BCM is noted for issues with the printed circuit board that can affect things like the security system and retained accessory power.

 

[BrendanW0214]

When the crankshaft position sensor is “going out” it's going to set a code. I don't know enough about the V6’s ICM to know what codes it sets. You could find this out by looking in the factory service manual. Have you downloaded a free copy?

There are two critical components that control the fuel pump. The PCM decides when to turn the pump on, based on two factors - 1) are there any codes set that prevent the PCM from turning on the pump; and 2) did the PASS-Key II (VATS) system, incorporated in the body control module (BCM) recognize the resistor in the ignition key and send the “fuel enable” signal to the PCM. If the PCM is not receiving the “fuel enable“ signal from the BCM, it sets a code and will not start the pump. Would also set a code in the BCM. If the starter is cranking the engine, the key resistor has been recognized. The BCM is noted for issues with the printed circuit board that can affect things like the security system and retained accessory power.

Gotcha. I should add I never got any SES lights during this escapade. That's very interesting info actually. I do apologize for sounding like an absolute idiot during the course of this thread if I did, but I'm a new guy to GMs so I guess we all have to learn at some point. Admittedly me and my mechanics are scratching our heads on this, but I'm beginning to think it could be something computer related or worse come to worse I just got a bad pump and need to put in a new one, as irritating as that would be.

 

[BrendanW0214]

Here’s an update: My mechanic wasn’t able to reproduce what was going on so I’m going to pick up the car tomorrow. He suggested it could be something as simple as a bad chip key for the ignition or an ignition switch but I’ll do my own troubleshooting and see what I can produce.

 

[Injuneer]

A bad chip key turns on the “SECURITY “ light. Read this:

4th Gen LT1 F-Body Tech-PassKey/VATS

If the starter engages and cranks when you turn the key to “START”, there is no problem with the chip key.

Is your SECURITY light staying on solid, or flashing when you turn the key to “START”? Does the SECURITY light come on briefly during the bulb check, when you turn the key to “RUN”?

If I am reading your posts correctly, the starter always cranks the engine, but sometimes the engine doesn’t start???

 

[BrendanW0214]

A bad chip key turns on the “SECURITY “ light. Read this:

4th Gen LT1 F-Body Tech-PassKey/VATS

If the starter engages and cranks when you turn the key to “START”, there is no problem with the chip key.

Is your SECURITY light staying on solid, or flashing when you turn the key to “START”? Does the SECURITY light come on briefly during the bulb check, when you turn the key to “RUN”?

If I am reading your posts correctly, the starter always cranks the engine, but sometimes the engine doesn’t start???
[

the issue is an intermittent failure of the fuel pump to opeeate although it has brand new fuses, a new relay, a new filter and a new pump that started out of nowhere on a really hot day, but after some time to cool down it starts normally. That probably got lost in the post so I apologize if it did. As far as the security light is concerned, it does stay on during the bulb check but is usually never on when the car is running. When I turn the key to start I want to say it flashes. Admittedly I never paid attention to the security light, but tomorrow I will observe it and see what it does.

 

[BrendanW0214]

Apologies for the double post, but I brought the car home today. On the topic of the security light, it does flash when the bulb check is occurring, but does not stay illuminated when the car is actually running. My mechanic told me that for his money, it could be the pump heat sinking as Injuneer said in the first reply and that it would probably be best to swap it at some point since something could have happened that would have caused the pump to act this way out of the blue for his two cents.

 

[1993TransAm]

You said the "SECURITY" light is flashing during bulb check...is it flashing during cranking when the car will not start? The bulb will illuminate for a few seconds during bulb check, and then turn off. (That is normal.)

 

[BrendanW0214]

You said the "SECURITY" light is flashing during bulb check...is it flashing during cranking when the car will not start? The bulb will illuminate for a few seconds during bulb check, and then turn off. (That is normal.)

I think I recall it doing that if memory serves me right. Truth be told I really was not paying that much of attention to it.