01 gt stumbles at 4k

aar0s · Jul 14, 2010

The cars been sitting for a few months so me and the wife decide to drive it to the school where she works, about 20 miles away, last sunday. car drove fine there but on the way back it felt like it had a miss that started around 4k then at like 3k and by the time we got back to town the car was sputtering and barely made it home. I chocked it up to bad/old gas, put some seafoam in it and changed the fuel filter but it didnt help. there was no check engine light so im not sure if there would be a code stored on it. any ideas?

Deleted member 38176 · Jul 14, 2010

Start with cleaning the MAF

aar0s · Jul 15, 2010

Nightfire said:
Start with cleaning the MAF

not a bad idea, it probably needs it, but the problem starts after the car has been run a while, after it gets warmed up. If its cold the car runs fine.
Ive just about got it down to a quarter tank, im going to drive it around the block afew times and let it idle for a while before i try a few gallons of fresh fuel, see if that dont help some.

trombonedemon · Jul 16, 2010

Thus the problems arise when a car sits for long period of time. Fire, Fuel, or Air. Either way, sounds like a tune up is in order, you know, plugs checking COPs, Filters, Oil change.

aar0s · Jul 16, 2010

Is there a method for checking the COP's? If one of them were acting up would it give a CEL?

twogts4us · Jul 16, 2010

Bad cat(s) or bad O2 sensor(s).

Maxpowers · Jul 16, 2010

aar0s said:
Is there a method for checking the COP's? If one of them were acting up would it give a CEL?

Most times will not throw a CEL until it gets bad.

Pull one at a time while running and see what the motor does. If no change, then the COP is bad

aar0s · Sep 7, 2010

got my buddys scanner over the weekend and went to see if there was any stored codes and to run a koer test. it came back with a cylinder five missfire so i pulled that plug and it looked fine, reinstalled it and started it to do another test. cleared the codes and did the koer test again and it gave me a p1000 code, something about the odbII not completing the tests. anyone ever seen this P1000 code?
edit- its p1000 OBD-II Monitor Testing Incomplete

nyuk98gt · Sep 8, 2010

aar0s:

P1000 occurs every time that the keep alive memory (KAM) is cleared (reflash of the PCM or disconnected battery). Nothing to worry about. It means that the engine has to complete a full drive cycle so all of the monitored systems can be checked and confirmed to be in good working order.

Chris

aar0s · Sep 8, 2010

what do ya mean by a Drive Cycle? i took it out after i cleared the codes and drove it some and the code is there still, do i need to drive it more for the computer to clear?

joshjwc9 · Sep 8, 2010

Yes, there is a certain way to do it quicker by using certain steps, but some simple driving around town up to certain speeds and idling the vehicle will do the same. I would start with pulling the COP's and checking the boots for any tiny tears. The spark my start to arch there and make it seem like a misfire.

And yes, now would be the time to change the fuel filter if you haven't done it recently.

aar0s · Sep 8, 2010

fuel filter was the first thing i did, figured that was the culprit but it was not. Ive got a class tonight, ill drive it to that and back and see if that dont clear the code.
oh, the only code that the KOER test gives me is the p1000 code, before i cleared the misfire code from memory the KOER test came back clean.

nyuk98gt · Sep 8, 2010

aar0s:

Google "Ford drive cycle" and you will learn all there is to know. Essentially, it allows the engine and emissions systems to cycle a time or two to learn fuel trims and confirm that everything (emissions-wise) is working properly. You'll need a cold start, too.

It can take up to a week of regular driving to complete a drive cycle. The evap system is tricky to get to cycle enough to clear the test hurdle because it depends on several things, including ambient temperature.

P1000 does not affect drivability. It only affects whether the car appears ready for an OBD-II emissions test (conducted by most States these days).

GL,

Chris

aar0s · Sep 8, 2010

great, this is a car that gets driven maybe once a week. oh well, have to make a point to give it a nightly drive.
drove it to class tonight and it ran fine there and back, but given the distance it would but if i drove it any further it would have started to cut out. ran the KOER test when i got home and still came back with the p1000 code.

aar0s · Sep 9, 2010

kinda going out on a limb but would a bad ECT cause the stumble and eventual stalling and not starting that im having?

wmburns · Sep 9, 2010

Consider that the COP has a very powerful spark. It is so strong, that if a misfire is allowed to continue, it will damage the boot insulator. The spark will leak out and because of the COP design it can not be seen.

Has there ever been in moisture in the spark plug wells? If so, this could also be the source of boot damage.

Autozone sells replacement COP boot insulators. Consider replacing some. Be sure to use silcone di-electric grease on the inside insulator.

This car will never run right as long as there are any misfires.

Consider having your injectors cleaned. I have had great luck with an injector cleaning service such as injectorrx.com. Once cleaned and flow tested, they are as good as new.

What is the fuel pressure? Esp when it stumbles.

aar0s · Sep 9, 2010

as far as i know there hasnt been any moisture in the plug wells. When i pulled the COP the other day i didnt see anything wrong (no tears or holes) in the boot but i will give it another look tonight.
still dont have any way of checking the FP, im going to have to invest in a gauge for it i guess.

trinity_gt · Sep 9, 2010

I would swap the COP on #5 with the one on, say, #1, clear the codes and then see if the problem reappears and if it does, determine if it stays with the cylinder or follows the COP.

To clarify: The COPs and possibly even the PCM can be damaged if the COP is run without a plug present at all. Although COPs have the ability to generate very high voltages (tens of thousands of volts), the amount of voltage actually generated will depend on what it takes to ionize the smallest gap in the circuit. This is normally the plug gap (e.g. ~0.054"). With no plug, the "gap" is massive and the voltage in the coil can go high enough to blow through the internal insulation before the "gap" breaks down. The resulting Inductive spikes can also play hell with the coil driver in the PCM.

A misfire only means that the cylinder failed to contribute on the power stroke. It could mean that the plug is fouled (e.g. shorted across the terminals), that the coil is unable to generate enough voltage to ionize the plug gap sufficiently to get a spark there, the fuel mixture in the chamber is wrong (too rich or too lean), there is insufficient compression on the cylinder and so on.

The easiest thing to try is to move the coil and see if the problem follows it.

aar0s · Sep 9, 2010

good idea, ill do that tonight. Ive still got to drive it enough to get the P1000 code to clear before i can pull any new codes.

aar0s · Sep 9, 2010

swapped the #5 and 6 COP tonight and took it for a drive and as usual about the time i started back home it started cutting out at 4k and by the time i got home it wouldn't rev over 3k. ran the KOER test and came back with the P1000.
would a misfire or bad plug make it so the car gradually ran worse and worse till it stopped running all together?

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