Cbird

Been having a problem with my car and upon further review I've decided that my car stutters and hesitates when accelerating (before I thought it was trans related)

What happens is I'll be accelerating and then all of a sudden you will feel the acceleration stop. Imagine you are watching the tachometer, the RPMs are increasing linear as you keep your foot in the same position, then the car hicups and the rpms stop increasing, then back to normal.

You know when you let the clutch up quick and the car gets a little jerky, it's just like that.

Recent things I changed to my car:

Lucas ethanol treatment (Friend had an extra bottle, figured why not)
IAC valve restriction plate (re-used the old gasket, might have a leak there?)
Oil change, castrol synthetic
Thermostat, Coolant temp sensor
I had my battery unplugged for a long time doing some car audio stuff, maybe the computer is relearning stuff still?

I'm leaning towards spark plugs or the coils. What do you guy's use for spark plugs? Any that come pre-gapped?

Cbird

Forgot to mention that I just recently had a MAJOR coolant leak (I have the plastic coolant crossover seen on the 99-00 PI manifolds) and coolant got all over the engine.

Stevo86

Does it go me, meo, me, meo, meow? Sorry couldn't resist.

It kinda sounds like a misfire under load. Check the usual stuff. Spark plugs, coils, coil boots. Any codes? Also for spark plugs NGK all day.

Cbird

haha, yeah I think it's the plugs and the COPS. I'll replace those tomorrow.

What do we gap them at now-a-days? I know we never stick with the stock gap lol.

Martel

How about fuel, could it be a fuel pump or filter?

Stevo86

I would test those COPs before you just replace them. Besides if that is the failed part it is usually just the boot that goes bad. For a stock mustang .045-.050 should be good.

Cbird

Replaced the boots and coils on the COPs with some parts from duralast and got some NGK iridium plugs. Still have the issue but my car idles much nicer.

I had the fuel filter changed about a month ago but the fuel pump... maybe. Wouldnt a bad pump fail to deliver fuel when I'm flooring it in a low gear? I can floor it through the gears without an issue, just when accelerating in a high gear I get a hic-up. And no, I'm not talking about goosing it in 5th gear at 30 mph Just a 1/2 throttle pull in 4th at 40 will do it.

I'm gonna check for vacuum leaks tomorrow when it's light out. Tonight when I was at a red light I heard a high pitched leak sound. Possible, since I just did some work on the IAC valve right?