1994 - Lesabre, Fuel pump?

[Matt M.]

Last week when it got cold, I was running a little late for work and I didn't have a chance to let it warm up I hopped in and took off. It fired up as normal and acted kind of sluggish when it shifted - almost like it cut out for a split sec. It did it like three times, so I turned around and drove back to my house. Made a couple laps around the block and the car warmed up and it ran fine all the way to work (35 miles one way). I thought maybe I had some bad gas or something. I dumped a bottle of injection cleaner and topped it off with some fresh gas a couple days later. Car started fine 4-5 days in a row. Now the past couple of days its been really cold. The car will fire off immediately and then die within a couple of secs. It'll turn over forever and never fire. Then it will stutter for a few secs running and die again. Cranks over and over and eventually it fires and runs. I've been letting it warm up for at least twenty minutes in the morning before I take off. Car runs fine all the way to work and around town shutting it off and on. Its when it sits for an extended period of time and gets cold that I have this problem. Last night I started it around midnight and went through the above. When it fired up last night it was ran high RPM, I shut it off and restarted it again and it was choppy… rev, slow, rev, slow - sounded like it was firing on missing cylinders. Shut it off and restarted and it ran fine. Its got fresh gas and a bottle of heat in it from last night. This morning I went through it again, but it idled fine. I limped it into the garage and left it to thaw for the weekend.

I think my problem is the fuel pump or possibly the Electronic Control Moduel under the day could be going on the fritz again. Reading the other posts I know I need to check the fuel pressure and probably change the fuel filter as its never been done. I feel pretty confident I have good spark and ignition b/c it runs well once started and tries to run on the first try.

1. How difficult is it to change the fuel pump. Located in the tank, right?
2. How do I check fuel pressure?
3. Is the fuel filter located under the rear right passenger door?

Any help would be appreciated. Thanks

[maxwedge]

Get a FP gage and check the pressure at the fuel rail port, check for signs of raw fuel in the vacuum hose to the fp regulator. Filter is under l/s floor near the tank. Tanks comes out for a pump change. You may also want to scan it and check the coolant temp sensor readings to make sure they coincide with the morning cold temps.

[spinne1]

Originally Posted by Matt M.

1. How difficult is it to change the fuel pump. Located in the tank, right?
2. How do I check fuel pressure?
3. Is the fuel filter located under the rear right passenger door?

Any help would be appreciated. Thanks

1. If you don't have a shop and access to the right tools, it is potentially a difficult repair. I know because I just did it this past summer on my 92 and I do not have a shop or the right tools. I actually replaced my gas tank in addition to my pump due to excessive rust and broken plastic inside the tank. My fuel pump screen was also very clogged with gunk. The most difficult part was securing the new tank because the new tank straps did not seem to fit right no matter how I pressed them upward. It was a big struggle. I had to cut the old straps off and grind off the bolts because of excessive rust. It is not something I want to do again. It did fix my problem of having the fuel cut out during right-hand turns with less than 1/4 tank of gas.

2. You check fuel pressure by first buying or obtaining a fuel pressure gauge kit. Then, relieve the pressure by either removing the fuel pump fuse temporarily and crank the engine (then put the fuse back), or by doing it the poor man's way by getting a rag and putting it under the valve on the fuel rail and pushing the center valve stop with a screwdriver. A small bit of gas will pour out onto your rag. You then remove the rag. This would not be recommended by any official source, but it works. You then attach your gauge to the fuel rail valve. You then crank the engine for a few seconds while watching the gauge and note the fuel pressure. The engine will start and run. Shut it off soon after. Actually, the directions for exactly how to test it will come with the fuel pressure gauge. Follow it instead of doing what I say.

3. You already have been answered. On my 92 the filter is under the car near the front passenger seat along the "frame."