94 Lesabre - Loses fuel when hot, pump wont charge nor engine fire. Please Help!!

[cbake6807]

Hello Everyone,

Thank you for taking the time to read my distress call.

I have a 1994 Lesabre 3.8, 130k mi. Recently the car has started dying on me after about 20 minutes of driving/running. This happens in stages. Around 10 minutes, the engine will crank but not fire unless the gas pedal is slightly tapped. At that point it fires and runs ok. After about 20 minutes, the fuel pump no longer appears to be charging. No audible confirmation of it working either. The enging will turn, and "occasionally" fire with extreme gas pedal actuation but never remain running. If the car is left to cool for approx 20-30 minutes, the problems dissapear.

Diagnostics I've ran: (forgive my bad memory, as this has been quite a while since I did some of the tests.)

AutoZone Computer: Couldn't read codes
GM Computer: Fuel too lean, EGR valve high(something), O2 Sensor low

Garage #1 insisted that my converter was clogged. I recently replaced the muffler and had them disconnect the converter. The heat check and visual inspection was perfect. No signs of any carbon buildup or anything burned in there.

Garage #2 - Insisted that the fuel pump was bad and also possibly a return line was leaking or sucking air.

Prior to testing, I had changed the fuel filter. the filter was in bad shape and could barely let any fuel through. This seemed to help for a while, but eventually got even worse; to the point i'm describing now.

My Efforts:
Replaced Fuel Filter - (noticed fuel lines near tank were rusted pretty bad - I don't believe I accidentally crimped any during the removal.)

Replaced Plugs/Wires - (Notices plugs were extremely clean with just a little yellowy color)

Replaced several vacuum hoses that were brittle and seeping air.

Removed multi-port casing - (full of burned gas deposits and gunk)

Removed intake - (gasket partially blown in 2 places - oil/coolant)

Removed EGR Valve - (some buildup, but valve opens/closes easily)

Removed Rocker Arms / Rods/ Lifters - (Rocker arms contained 2 radial bearings each which were extremely worn. Alot of play in the bearing and also the rocker shafts that mount the bearings were worn and very loose.)

I'm going to replace arms, bearings, rods, lifters, and gaskets in hopes to regain some compression and power. The engine always had a dead spot when you would accelerate beyond a certain pedal position.

My best guess is it's either the fuel pump heating up and crapping out, OR it's some sensor thats getting too hot. The Throttle position sensor sits directly above the exhaust manifold, and seems like it could be getting hot.

I've checked all the relays on the firewall, but couldn't locat one that would activate the fuel pump, to test for power when it's not working.

Please feel free to ask me any questions you may have.

I'm very desperate for help. I need to get this car back up and running, because my other buick has a date with the lake.

Thanks soo much in advance.

Chris Bake
[email protected]

[cbake6807]

I apologize for posting this message twice, the forum told me I was not logged in after submitting, assuming the post didn't work, I logged in and posted the message again.

[ChemMan]

Have you checked fuel pressure at the fuel rail? From what you have described, it sounds like your fuel pump is suspect. However, I would wait and see what a few others think.

[cbake6807]

Thanks ChemMan,

I suspect that also, but after reading around about similar problems on here, I've decided to check the Crank Sensor and since im in the overhaul mood, replace the chain too. I'm going to try that 'pot of boiling water/resistance check' someone else had suggested in another thread.

Bottom line is, that tank is going to be a real pain. The strap bolts are rusted and busted beyond repair. I'm going to have to hacksaw the straps and engineer a new way to hold the tank up.. I just didn't want to deal with it, if it wasnt the problem. I just dont see how the pump can just start or stop. There's no in-between where you can hear the pump "trying" to charge or crapping out.

I haven't shelled out the 40 bucks for the pressure checker yet. If the crank sensor proves itself to be good, I will.

Thanks for the advice!
Chris

[ChemMan]

Best piece of advice I can give you is this: If you can't troubleshoot something down to "X", only "X, Y, or Z", then start with the easiest/cheapest and work your way up. Yes, the crank sensor maybe cheaper than a good fuel pressure gauge, but it is a hell of a lot easier to check the fuel pressure, then rip the front engine cover off (granted replacing the chain may not be a bad idea). But, assuming you've looked at the procedure and have the necessary tools (you won't be removing the crank pulley with a 3/8" ratchet), then more power to you. Good Luck and hope the crank sensor is the culprit, as you'll be killing a lot of birds with one stone. I would recommend further troubleshooting, and personally would not feel comfortable in your situation. If you need any help please chime in and hopefully you can get that biatch running soon.

opcorn:

[TheDeal526]

your issue sounds very similar to my 93 lesabre. no shop could pull any codes because my check engine light never came on. i was told the ignition control module are known to go bad and cause the engine to stall, especially when the engine has warmed up. i was also told the crank sensor could have gone bad. i just replaced both parts and never had a stalling problem again. the ignition control module was easy to replace, but it cost over $120 from pepboys, (gm wanted over $300). the crank sensor was pretty cheap, but removing the harmonic balancer to get to it took my mechanic 2 days. good luck, with both your buicks