Surging problem

[Swindez95]

Ok guys ive got a problem, a surging problem. And the vehicle is a 95 Maro' with a 3.4L. For the past few months or so now my car seems to have intermediate throttle hesitation and it doesn't always happen everytime but mostly around 3000 rpm's and up. It's nothing major like fall on its face bad but its definitely noticeable. Ive got a full MSD Ignition, new E3 spark plugs, a fuel filter with about 15k on it, and a clean k&n air filter. The machine has 214k on the clock so its a little tired but its got plenty of power on tap. Here lately its also started to run really rough when cold and just the other day while under load it started missing on what I thought was at least two cylinders. I know the MSD ignition is hard on stock coils and I know these are factory coils with 214K on them but I wasn't so sure that a coil breaking down would also cause a surging just an immediate missfire. The only other thing I have been able to think of was possibly fuel pump getting weak or maybe a fuel pressure regulator.

If any of you have any ideas or have experienced a similar problem id be glad to hear about them. Mainly I just wanted some more opinions before I start diagnosing and replacing parts since im saving up for another vehicle at the moment.

[flamingchicken]

Re: Surging problem

is it like an occasional miss? like rrrrrrrblahrrrrrrrrrrrrrrrrblahrrrrrrrrrrrrrrrrrrr rrrrrrrblahblahrrrrrrrrrrrrrrr?

[Swindez95]

Re: Surging problem

Yes its very random and occasional. I think im gonna go ahead and order a fuel pump for insurance and get the holley AFPR just to do some tinkering. And while im at it I might as well go ahead and change the coil packs since they are only 20 a peice with my discount at my local advance auto. I think im also going to ask my local shop what he would charge to do a factory reflash on my PCM as well. Ive read an article of someone with a 3.4 F-Body who gained a few more miles per hour just by simply having his PCM flashed with the factory tune again. I dunno I guess that after time some of the data on the flash chip could degrade. It would also make since that his mpg had diminished to about 16-18 mpg from about 22-24 when he first acquired the vehicle which is exactly what ive witnessed from my own vehicle. 50k ago I could muster 25-2 mpg 65-75mph highway cruise...now im lucky if I can squeeze 21 highway driving 60-65mph and ive changed nothing as far as the weight of the vehicle in that time.

[tkoforpresident]

Re: Surging problem

coil packs.

[Rob Bell]

Re: Surging problem

If I were you I would do some diagnostics before you start throwing money at it.

[Swindez95]

Re: Surging problem

Well either way im going to have to start throwing money at it. Its in need of it actually, its got 214K without having anything majorly mechanical or electrical for that matter ever replaced or really maintained besides the normal plugs, wires, brakes, tires..etc. Hell to give an idea of just what has been done, since ive been driving her in the last 5 years from 123,000 to where the clock sits today I havent even had to replace the belt or hoses.