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whty98

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Ok well, today I drove about 30 on interstate, parked to eat dinner, get back out and start her up and she is missing. WTF, nothing was touched. I don't know what is wrong. What could cause this? I filled her up thinking it was bad gas, with 93 from BP and still messing up. I reset the computer by unplugging her and nothing happened. Looked at vacuum lines and essentially everything I could think of. The spark plugs,wires, fuel filter are a year old. I am going through finals week and this just made my life hell, and then I have to drive home for 2 hours on Friday, and that's the only place I can do the work at. Is it safe do drive or do I need it fixed? What could cause this?
 
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whty98

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Oh ya, I have a 98 GT, stock except exhaust, shifter, the normal mods.
 
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whty98

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It's like a spark plug not firing while idling. Under load, it will stutter past 2200 RPM. I was just thinking it could be not getting enough fuel, but then wouldn't the fuel pump just not be working?? Or could my fuel filter or injectors be dirty or plugged or even a dirty MAF, even though I just cleaned it two monthes ago. I upped the octane and I'll add some injector cleaner tomorrow and see what happens. I am too tired and stressed to think about it right now.
 
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GREG@SN95

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check TPS
clean MAF
run fuel injector cleaner
change fuel filter

do this

remove fuel line (have something to plug it ready) and start car... if fuel pumps out the line (you will want a bucket to catch fuel) then the pump should be OK...

you have COPS so... I'm not sure of the procedure of changing plugs... but you may want to do that...
 
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whty98

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I've changed the plugs when I did the MSD wires a year or so ago, they are no problem. Can't I just stick a guage to the fuel line and get the pressure? BTW, what's COPS?

Ican do all of that, when I get back home. So can I drive her without any damage for 2 hours??
 
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GREG@SN95

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whty98 said:
I've changed the plugs when I did the MSD wires a year or so ago, they are no problem. Can't I just stick a guage to the fuel line and get the pressure? BTW, what's COPS?

Ican do all of that, when I get back home. So can I drive her without any damage for 2 hours??
fuck... for some reason i thought your car had COPS (coil on plugs)

so you have a distributor...

check the cap and rotor (or just replace)

As far as the checking pressure... you could... i dont know how though... i don't have the tool... i always use that redneck method...

but still check/clean the TPS (throttle postioning sensor) MAF (mass airflow sensor) fuel filter, and run the injector cleaner...

also... you should not run 93 unless you have a tune for it or advanced timing...
 
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whty98

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I have a 98 4.6 GT, so I have have coil packs, not a distributor :hammer: JK man. I just put the higher octane gas to balance out any bad gas there may have been. I also thought the IAC could be bad, but I also cleaned that a month or so ago with TB cleaner, but my car does have 109K. It just pisses me off when this shit happens at the worst time.

So should I drive her?? I had to drive for 30 minutes while it was doing this soooo.....can I get away with it? I hate to spend the money at a shop but I don't want to fuck her up.
 
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GREG@SN95

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whty98 said:
I have a 98 4.6 GT, so I have have coil packs, not a distributor :hammer: JK man. I just put the higher octane gas to balance out any bad gas there may have been. I also thought the IAC could be bad, but I also cleaned that a month or so ago with TB cleaner, but my car does have 109K. It just pisses me off when this shit happens at the worst time.

So should I drive her?? I had to drive for 30 minutes while it was doing this soooo.....can I get away with it? I hate to spend the money at a shop but I don't want to fuck her up.

not if its running lean
 
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GREG@SN95

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whty98 said:
I have a 98 4.6 GT, so I have have coil packs, not a distributor :hammer: JK man. I just put the higher octane gas to balance out any bad gas there may have been. I also thought the IAC could be bad, but I also cleaned that a month or so ago with TB cleaner, but my car does have 109K. It just pisses me off when this shit happens at the worst time.

So should I drive her?? I had to drive for 30 minutes while it was doing this soooo.....can I get away with it? I hate to spend the money at a shop but I don't want to fuck her up.

and try this then...

start her up... and pull off the a wire... if it runs different, then plug it back in and repeat on the next...

if you get to one where there is no difference in how she runs... then you have found either a bad injector or plug... and know which piston the problem is at
 
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whty98

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HAHA, that's funny because I actually did this and one cyclinder actually did not affect it, at least not very much I think. I was at a truck stop and semi trucks were everywhere. I wonder what is wrong, the wire, injector, or plug. But then wouldn't it not stutter hardcore if it were just one cyclinder?
 
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GREG@SN95

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whty98 said:
HAHA, that's funny because I actually did this and one cyclinder actually did not affect it, at least not very much I think. I was at a truck stop and semi trucks were everywhere. I wonder what is wrong, the wire, injector, or plug. But then wouldn't it not stutter hardcore if it were just one cyclinder?

it'd make a hell of a difference...

so your filter is ok
your pump is ok...

My guess... either the plug is fucked (you just changed so i doubt) or its the injector...

TRY THIS!
switch the cable (that yeilded no change in how the motor ran) with one of the other wires... pull a wire... put back... pull the other, put back... if its the same cylnder then its probably an injector... if the problem jumps... then get a new wire...

run injector cleaner... and if that doesn't fix it then you may need a new injector...

YOU CAN ALSO TRY!

unpluging the injector wires the same way you did with the plug wires...
 
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whty98

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Good point about checking the wires, and then just simply unplugging the injector. Hopefully these lead to some conclusion tomorrow...maybe even the problem will fix itself :rollinglaugh: I'll get the injector cleaner and run that through and pray.
 

STNG_96

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Ok, this previous summer the EXACT thing happened to me. Started all of the sudden, only at certain RPMs. What happened to me was at the back of the intake manifold on the passenger side, there is a metal tube that comes out of the composite, which is where your coolant leaves the manifold. So what happened was where the metal met the composite, it had cracked and it was leaking coolant into my number 4 cylinder, which would make it miss, TERRIBLY.

So what you need to do is one, check that fitting first, see if there is any residue or whatnot of some coolant. Secondly, pull off the spark plug boot and just take a big smell. If that is what is happening, believe me, the smell of coolant is evident.

Finally, if that is what you figure out is your problem, stop driving immediately. The coolant will seize the plug to the head, and the next time you replace plugs you will take the threads in your head out with it.

Good luck
 
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whty98

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Ok so I have replaced my intake with a non-PI alumium cross-over one about 2 years ago (when I didn't know about the PI one...dumbass). I looked at the boots of each spark plug and injector for coolant or leaking fuel, nothing dry as a bone, except on the bottom of the back passenger spark plug boot but there was hardly anything which may have also caused it by making the plug wet. I really can't afford a PI swap right now at all because I ruined a head. Shit, I really should have investigated further but my mind is shot, after my final (3 out 5) I'll look into and post.
 

STNG_96

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Actually I had my manifold replaced two years ago as well, also with the aluminum crossover non pi manifold. That was the one that cracked at the back on me. Now, you said there was only a little moisture, well that is all there will be. I actually didn't see much moisture at all down in there, but the smell was evident.
 
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whty98

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I'll just have to take a closer look (and smell) tomorrow in the day. I know what coolant smells like so I should have smelled it when I opended my hood and stuck my head down there,but we'll see. I'm getting anxious to know, I want my baby back in tip top shape
 
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whty98

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Well today I didn't get around to her until after dark. I found that the back passenger cylinder had coolant in it. I don't know how it got there because I don't see any leaks, coolant or anything. I changed the hoses 2 months ago so how the hell could this just be messing up like this??? The coolant is sitting right on the spark plug. Sooo...tomorrow I get to buy new tools and a new spark plug and see what happens.

I took each wire off one at a time and each time in noticed the same thing. Then I did the injector wire and it did the same thing each time. She seemed to be fine during idle today but the same underload. So maybe it's a fuel thing. I also added fuel injector cleaner with the half tank of 93 and half old 87(which I thought was maybe bad).

The first thing I noticed was that when I started her up for the first time today, she ran perfect...WTF. Then I drove about 10 miles (running perfectly, even under load). Got back out and then she started acting up. I went down to some repair shop and the bumbasses their didn't help out all. Some prick just jumped in my car and said he'll have to take a test drive, fuck that duesche. So I said I would drive and show him, well as I was in 2nd hitting the gas, I cut out for a second and then stuttered. I left and then parked at Sears to inspect it and some retarted kid (like ~15) pulls up in a 96 cobra and he asks me what's wrong and then is like wanna race? :gtfo: I wanted to kill him, then I asked about his car :hammer: he wrecked her in a ditch the first night he got drunk a week ago, and he has ebiach shocks and struts and stock springs (the thing was hella low).

So in conclusion today noticing was really accomplished. If the spark plug doesn't work tomorrow, then a new fuel filter
 
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GREG@SN95

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is there still coolant in the cylinder?

pull that plug again... if its still there you may have blown headgasket or cracked head...
 

STNG_96

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I'm sorry if I sound mean here, but did you not really listen to anything I said? The reason that the car didn't miss when you started it up today, is because the coolant that was in the cylinder from before was gone, and the car hadn't leaked any more into the cylinder to make it miss. I would be willing to bet money that what happened to me is happening to you. See, what happens is, over time, the heating and cooling of that boot, but the coolant on it will make it shrink, which is then how you start getting coolant down into the cylinder. In my opinion, there is no reason to try to check the fuel filter, or the plugs. If its not the problem now, it will be soon.
 

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