I know this is a mustang site but...

[SlowRS]

I am having problems with my formula and you guys may have some insight. Please no "because its a GM" or whatever. Serious answers only please.
A couple of months ago, we replaced the fuel pump. The car wouldnt run at all. Replaced the pump, fired right up. Anyway, after several months of running great, I was coming down the highway, when the car started surging, the it started coughing like it was gonna die. I got it of to the shoulder just as it shutdown. Tried refireing it several times, to no avail. After sitting for about 10 minutes, It started right up and I took off down the road, running fine. Got about a mile then it started again. Got off the road, shut it down, waited, then fired it back up. Started and idled fine, so I took off like a bat out of hell, trying to get to the next exit, which i made it to bout 7 miles away, where it dies in the intersection. Wait a bit, fire it up and pull into a gas station. There are a few things that I think might be wrong, like

1: My gas gauge is WAY off and I am out of fuel. The reason it starts again is fuel draining back into the tank

2: I took an interchange and my gauges dropped way past E, maybe causing the pump to suck up some dirt or something.

3: The temp out side was about 100 degrees, could it have been vapor locked?

Anything else that it could be. I need any and all suggestions. THe car is going to be towed next week and I will take a closer look at it then.

If it is the pump, it will only take me about a half hour to change, as I have a trap door.

[Black Horse]

Did you replace the fuel filter?

[Mustard]

[QUOTE=Black Horse;299617]Did you replace the fuel filter?[/QUOT

What he said

[BIGHONKEY]

You don't top off your gas do you?

[SlowRS]

Yes, the filter was replaced when we did the pump.

My gauge read nearly half a tank, and was planning on filling up before I got to work, which was only about 30 more miles.

[blueoval4ever]

I had the same problem with a Mercury lynx a long time ago, it would run for a while then start cutting out like it was out of gas then die. After a short wait, you could start it up and it would run fine. I thought it was vapor locking and was told by a few other people it was too. ended up being the ignition module, I guess it would get hot then stop working. May be worth checking into.

[Buckeye]

2 things 1 where did you get the pump? I use at the min a napa pum if a delco pump is not avail. DON"T use a az pump! Sounds like it is bad. 2 F-bodies REALY don't like being run emty. I have seem many take a complete shit doing just that. The fact it runs after cooling off tells me that the pump has a high chance of being bad. Take a pressure reading. Also check in over at COFA and see what else the say.

Also read into the Trap door mode for the fuel pump. I don't like it but with the trouble you have....

[tim c]

check the fuel pump relay

[Mista Bone]

What kind of pump did you put in?

If it was from the GM dealer, there is your problem. Get a Walbro from APE or a local shop.

GM fuel pumps in general
1/3 die in the first month
1/3 don't make it past the first year
1/3 never have any problems

Try learning this on a Escalade with a 30+ gallon tank.......which was always near full when the pump acted up.

[Mustard]

I had the same problem with a Mercury lynx a long time ago, it would run for a while then start cutting out like it was out of gas then die. After a short wait, you could start it up and it would run fine. I thought it was vapor locking and was told by a few other people it was too. ended up being the ignition module, I guess it would get hot then stop working. May be worth checking into.

I had the same thing happen to me with a bike I had. Talk about a pain in the ass.

[black90lx]

it might be the coil

[bcoh5gt]

sounds like an optispark

[e5shea]

http://www.dayton-fbody.com/

[blk93notch]

i had a problem like that with my cavalier. it was the fuel pump. it was a newer pump also. it would overheat and shut off. after it cools down it started fine. hope this helps.

[Timido]

I dont know if this helps but alot of the crank sensors on newer GM stuff goes bad with heat.

[BIGHONKEY]

Could be low on halogen fluid

[BLACKHAWK]

sounds like an optispark


i'd check that out if its a 93-97 formula

[347sc]

What kind of pump did you put in?

If it was from the GM dealer, there is your problem. Get a Walbro from APE or a local shop.

GM fuel pumps in general
1/3 die in the first month
1/3 don't make it past the first year
1/3 never have any problems

Try learning this on a Escalade with a 30+ gallon tank.......which was always near full when the pump acted up.


I install em all day long and dont have any come back. One pump doesn't mean they are all junk.

[americanricer87]

Same thing happened to my friend. It was the new fuel pump he put in. Check your fuel pressure. His showed 10lbs till he tried to start the car and the pump shut off.

[SlowRS]

Its a walboro pump. The car will be towed back tomorrow, so I will start looking into everything. Thanks for all the info.