No acceleration issue--think its electronic...

[adrivinfool4u]

I've had this problem for a few days now and can't figure it out. When driving for more than a couple minutes, the car will get to where I can't accelerate much at all. If I press the gas more than a tiny bit or get less than 6 or 7 lbs of vacuum on the gauge it will just lay down and stutter. If I keep pressing the gas it will die, but if I let back off to a certain point it will try to go again. Also, when not under load, it will rev like normal. I have all new ignition (plugs, wires, cap, rotor, coil, HEP), new fuel filter, cut the cat off to see if that was blocked (wasn't annnd I kinda wanted it gone anyway), etc. I hooked up a fuel pressure gauge and have good rail pressure sitting there (the hose in my guage isn't long enough to use it while driving though). Last night, I was driving around and once it started acting up, I just pushed the clutch in and switched it off. I cranked it back up and the problem was fixed (for a couple minutes). I guess some circuit is resetting and fixing my problem when I turn the car off and on again. Any ideas? I'm not getting a check engine light. My only other idea is the coolant temp sensor, because if I check the codes, that's the one that never goes away (even though it has been like that since I've had it with no driveability problems). Can I unplug that and drive it to rule it out (like how you unplug it to set the timing)? Sorry for the long post, but I'm hoping all that background will help narrow the problem down. Any ideas??? Thanks.

[moparfreak3]

Sounds kinda like a fuel pump on its way out. You will have good fuel pressure sitting there but it will drop off when the demand for more volume is present. If there was a way that you could watch the gauge while you are driving you will probably see the fuel pressure drop off.

[EvilcowRoland]

+1. Sounds like a fuel pump dying.

Unplugging the CTS will set off the power loss light and make the radiator fan run full time, but it is still drivable that way. The CTS would not cause the engine to bog like you're describing.

[moparfreak3]

Only problem with driving the car when the cts is unplugged is you will only get your base timing. The computer will not give it any advance like it should.

[adrivinfool4u]

I need to find a longer fuel pressure gauge hose I guess. The only reason I question the pump is how I can switch the car off and when I crank it right back up, its fine for a couple minutes.

[moparfreak3]

Fuel pumps are screwey like that. You may also have something that is clogging the sock filter in the tank and when the pump turns off it isn't sucked onto the pump anymore. I dunno if it were me I would replace the pump with a 255 walbro when you replace it though.

[adrivinfool4u]

Well, I got home and dug out my fuel pressure gauge--turns out the end at the gauge is 1/4 NPT. I went to Home Depot and got some barbed fittings and used a section of 1/4" injection hose to make it long enough to tape to the windshield.

Anyway, you guys were absolutely correct! The highest pressure I ever saw was 50 psi, and it mostly hung around 45. I kept driving around the block, and it started choking out again. Pressure hovered around 45, but when you give it a little gas under load it'd drop to 20 and 15 sometimes. Thanks for steering me in that direction--I like to have a clue before throwing parts at problems.

[moparfreak3]

No problem we have all pretty much had that issue at one time or another. Time for a walbro

[EvilcowRoland]

Yeah, I've seen that exact fuel pump issue twice. And once with a TBI fuel pump after a turbo conversion. The TBI pump actually held 48 PSI idle pressure for a while before it burned out.

[wicked93gs]

yeah, when the car acts like that, it may not be the fuel pump but its definately a lean fuel condittion of some type, clogged filter, maxed out injectors, insufficient pulsewidth, etc, glad you got it figured out....on the bright side at least you didnt go lean whil IN boost...that would be bad

[dklimek]

Ok so i have the same problem here with my car, it was sitting for a while and i noticed while draining the tank to put a new pump in it (pump was DOA when i bought the car) there was some rust in the tank. Well put all new lines (aside from under the hood, which im doing today) new filter and pump like i said. Car would have good vac but would never go over 5psi, and when it neared 5psi it would fall on its face! Its now gotten HORRIBLE, car wont barely run like described here...pulled the filter and when the line coming from the tank was disconnected there was a loud psssstttt noise that came from it, so im guessing the filter has already been clogged? Or should i be counting on the sock? It was driven VERY low gas-wise (less then a 1/8th of a tank) since i let my dad borrow the car so im guessing it sucked up alot of the shit at the bottom of tank. Thoughts?

[dklimek]

Ok just went and pulled the tank completley....it looks NASTY. Guess im looking at a new tank, if i have a 2dr "mazerati" lebaron...what all fits this thing tankwise? Is everything compatible?