Well I finally decided today that I wanted to take my car to the track. Non of my friends could go so I decided to go there myself. I dont have a trailer so I said screw it Ill drive the car there. BAD IDEA!! The track is about 1hr and 15 min from my house. I was driving the car along the whole time, and it was running suprisingly well, I was crusin at like 90 and the Temp was good and the car drove pretty smooth. So i get all the way about 10 min from the track and as I get off the highway on the first stop sign the car dies out . I had to let it sit for like 5 minutes before it would start up. So I get it going and I kept up speed and right as I slow down to turn into the enterance of the track the car dies again . I waited 20 min and then started it up and nursed it into the enterance. I thought my plugs were fowled out so i asked one of the guys in a trailer if he had spark plugs and tools and he did (thank you). And I pulled a plug and it seemed ok to me. So I waited another 20 min and l stated it up again and I had to keep the speed up and RPMS up to keep it from dying. I got it on the highway and it was getting worse and worse and Bogging horribly when I gave it any gas and just running horrible, then it finally died out (even at a high speed) . So i pulled over and called a tow truck. $145 and 2 hours later Im at home.

What could be the culprit??

Symptoms:
-after extended periods of driving the car dies out at low RPMS (running rich?)
-Bogs horribly when any I give it any gas
-after sitting for a while the car runs decently for a little bit then gradually dies out again.


Some Ideas:
-Needs tuning and running rich for and hour straight will make it die out when slowed down?
-on 1 or 2 of the plug wires the metal piece insde the part that goes on spark plug came out of the boots so I might not be getting the spark on those cylinders?
-Bad mass air?
-Fowled 02's from running rich? (Can bad o2's make a car run that bad?)
-Computer too hot from being close to heater hoses?


*Weird Side Note:
I noticed yesterday (with 1/4 tank) that the fuel pump was a lot louder than usual. I got some gas and it quieted down to normal. After I got the car home from the track (with about 1/2 tank) the Pump is extreamly loud again. Any ideas on whats wrong with that, and if it might be the cause of the other problem.

Also I was driving the car yesterday for about 25 min (the longest I drove the car) and one time from a stop it died when i tried to accelerate, but didnt think anything of it.

Sorry for the long post, but Im just lost on this one. Any help is appreciated. Thanks

Chris

 

sounds like an air intake problem, like the map and or maf is fucked. it would still run with fucked o2's and would get u home. it could be a combo of things really.

 

My guess would be bad fuel pump or bad O2 sensor/s.

 

could you have a fuel line getting to hot and vaporlocking? is it only happening when the tank is low. have you logged the fuel trims when it is acting up. are you throwing any codes

 

the pause and runs ok for a bit thing reminds me of classic fuel pump symptoms..

first thing i try when LS1s start running like crap on the side of the road, is disconnect the MAF... if the MAF is lying, the car runs like doggie doo.



but the pause reminds me of classic fuel pump problems.. even before you said it was loud..

 

If you have an external pump, that is likely overheating and locking up. Happened to me with the Aeromotive A1000 alll the time. You could gear the gas in the tank bubbling. Let it cool down and it would run fine, then same crap after heating it up again.

 

I agree, fuel pump or clogged filter.

 

Well I have a 255 walboro intank pump. The fuel filter probably had 100 miles on it so I think that should be ok. I can see it being a fuel pump, but that is new as well...unless something is wrong with it. So far Ive only had these symptoms when it was 1/2 a tank or less, but that could just be a coincidince. I tried the unplugging the MAF when I was on the side of the road, and started it and it started and ran for about 5-10 seconds then died.

I havent ran any codes yet because I dont have any sort of scanner or HP tuners or anything, and I had to go back to college today.

 

Put a fuel pressure gauge on it and find out what's going on. Everything I've read sounds like a fuel pump issue as well, the thing gets heated up and it won't work anymore until it cools down.

Maybe you've got your pump mounted too close to the bottom of the tank causing the new pump to overwork itself? Or maybe the in-tank filter is clogged?

 

...or the pump came loose from the in-tank assembly pickup tube.

 

when he said half tank, thats what i was thinking...

 

How would that give these symptoms? If the pump came loose from the assembly pickup tube it wouldn't send fuel through the lines. There isn't anything like a hose that extends off the bottom (feed portion) of the pump, its just a sock filter.

Or am I missing something here?

 

You're not missing anything, it's a shot in the dark with the only useful piece of info he posted...the symptoms vary by fuel level.

Without a scanner or at least fuel pressure gauge readings, it's all just guesswork.

 

well I dont think it is a sudden thing, I think it happened due to the fact that I drove the car for a long time. I think if I would have drove that far a month ago it would have done the same thing, I just never have noticed because I dont drive the car very far. I set the fuel pressure at 58 psi about 3 weeks ago, Ill check it again, but I doubt it will be different unless I drive the car for a long time again and check it when its running like crap.

 

if the pump comes off the bottom part of the holder, and is just swinging by its flex line, then its usually angled and agienst the bottom holder...

then you cant get the fuel at teh bottom of the tank... with a 3rdgen sensor/gauge, the last physical 3/8 of a tank reads as half a tank.. (thats why the last half tank goes down so fast)

 

yeah the shape of the third gen tank is crazy. Also, the fuel pump is dependent on a constant flow of fuel to cool itself...so when you run it low, it overheats and boom...you pump takes a **** on you, maybe permanently.

 

same overall shape as the 4thgen...........

 

So essentially I am going to have to drop tank again and check it out, unless there is another way? Ive dropped that damn rear end and tank twice already. O well, Im getting good at it now, hopefully I could get it all out in 45 min or so.

 

Do you have functioning 02 sensors? Coolant temp sensor in the head?

Car will run with MAF unplugged, so that's not it.

 

Before dropping the tank I would put a gauge on it and get it running bad. Make sure there's a fuel pressure problem before going thru all of the effort.