I have a stock 2000 GT and it started acting strange on the way home from work last night. I drove it about 15 miles with no problems at all and then I noticed that it started lightly bucking under moderate load. But under a light load it ran fine and it idled like nothing was different. I just filled up the tank with some gas and I'm wondering if that has anything to do with it. It feels like its missing but there isn't any weird noises and it idles fine. So far the check engine light has not come on. Im going to replace the fuel filter soon and I hoping that will fix it. Any ideas???
Power Loss
- Thread starter Metalli485
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whyask
New Member
whyask
New Member
So far it hasn't thrown any codes. I also noticed that I can rev the engine in neutral and it doesn't seem to miss any. It only happens when there is a moderate load on the engine. A light load doesn't make it buck at all.
How do you check for moisture in the coil? Just pull the COP off and look inside the boot?
How do you check for moisture in the coil? Just pull the COP off and look inside the boot?
I haven't washed my engine in a long time so I don't know why moisture would get inside the boots. Anyhow, I'll pull them off and check just to make sure. Aren't you supposed to put something on the boots to condtion them? If I pull one off and check the spark by holding a screw driver in the boot, won't the spark shock the snot out of me? I've been shocked through a plastic screwdriver handle before (the metal rod extends into the handle). I also plan on checking the injectors. I'd like to check the fuel pump but I'm not sure how. Any suggestions?
There is a spring that sits inside the boot of the coil. Honestly the coils on my car are powerful enough that I don't even need a screwdriver. I can just hold the boot close enough to a engine ground that it'll jump it. If you do use a screwdriver just make sure you don't ground your body to any metal part of the car. Besides, nothing like a little zap to wake you up in the morning!
Also refer to this post to get fuel pressure readings. Just hook up a fuel pressure gauge to the schrader valve on the fuel rail. http://forums.stangnet.com/showthread.php?t=675780&page=2
Also refer to this post to get fuel pressure readings. Just hook up a fuel pressure gauge to the schrader valve on the fuel rail. http://forums.stangnet.com/showthread.php?t=675780&page=2Well I just gone done doing unplugging each COP and each injector one by one. I didn't really get much out of it since my car only misfires when its under a load. I did notice one strange thing though. The injector on the cylinder thats closest to the firewall on the passenger side has a different kind of plug than the other injectors. It doesn't have the tabs on the side that you press in order to release the plug. I took it off and it isnt broken, its just slightly different than the other plugs. 
It doesn't look like anyone hacked into the wiring so I'm not sure what to think of it. By the way I bought my car used so who knows what was done to it. I guess at this point I need to unplug each COP and injector and drive the car to see what happens. If I keep driving my car over the next few days while I figure out whats going on, will it mess anything up?
It doesn't look like anyone hacked into the wiring so I'm not sure what to think of it. By the way I bought my car used so who knows what was done to it. I guess at this point I need to unplug each COP and injector and drive the car to see what happens. If I keep driving my car over the next few days while I figure out whats going on, will it mess anything up?
sicK96GT
New Member
pulling out a spark plug is easy, see what they look like and refer to a manual should tell you whats going on. Maybe hook it up to a scan tool and see if the o2 sensors are switching. one of mine were not switching and it wasnt throwing any codes.
Last night I just unglugged the coil because I was tight on time. Tonight I plan on taking them off the head to check the spark for each one. I haven't run it at WOT since the problem started. I assume if it runs okay at WOT I can rule out a fuel problem right? Also what is an engine ground?
Rickey_Bobby
New Member
AHHHH!!! don't arc, the coils to ground!!!
A fried coil can still produce a spark.
Read this, I posted a while back
A fried coil can still produce a spark.
Read this, I posted a while back
...suppose I should have read this first.
Rickey_Bobby
My Garage
Official Member Posts: 53
Join Date: November 2006
12-10-06, 06:08 PM
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I had a similar problem on my 99gt. Check this:
water or coolant around spark plugs. Remember NEVER wash down the engine
I had coolant coming out of the intake manifold gasket. Just barley, not enough to drip on the ground, but enough to make moisture in 2 plug holes.
if you EVER had water in a plug hole, you probably killed a coil or 2.
You can narrow your problem by doing the following. This will tell you where the problem is, and if it is spark, or fuel related.
1. Get your car in a state where it is misfiring. It must be misfiring for this test.
2. one at a time, unplug fuel injectors while the motor is idle. The engine should have a noticable lope when you pull each injector. This is GOOD. It means the fuel injector is working. If you get to an injector that DOESN'T cause the engine to lope when disconnected, or causes it to lope less than the others, suspect that cylinder. Do this 2 times each for each cylinder to see if you get the same results. Most likely, this is not a fuel problem.
3. Rev the engine a few times and then let it idle for a minute and make sure it is still misfiring.
4. assure that all injectors are connected properly
5. One at a time, go around and disconnect the plugs from the coils. Again, doing this should cause a noticable lope. If you get to a coil that when it is disconnected, it either doesnt lope, or causes less of a lope that the other cylinders, suspect that cylinder.
Ok, so hopfully now you have narrowed you problem to a specific cylinder(s) For this write-up's sake lets say cylinder #5 is your problem, but your still unsure if it is the coil or injector because during both tests, the engine still loped, just not as much as the other cylinders.
6. swap cylinder #5 coil with a coil from the other side of the engine. (You will need a small 7mm socket and extension to remove the bolt holding the coil down. And the coils will come out without removing the fuel rail.)
7. connect both coils to the wire harness and start the car. It should still misfire. Use the method in step #5 of this write up to see if your misfire followed the coil, or is still happening at cylinder #5.
(If the misfire followed the coil, you have a bad coil. whats worse, is the others are probably on their way out too. Replace them all.)
There is a guy on ebay selling genuine motorcraft coils for dirt cheap. I have them on my car and they work flawlessly. Here is the auction.
http://cgi.ebay.com/ebaymotors/8-OE...N_W0QQcmdZViewItemQQcategoryZ33689QQihZ009QQi temZ190040945028QQrdZ1QQsspagenameZWDVW
If the problem stays at cylinder #5, then suspect your injector.
8. Use compressed air to blow dirt off the motor before doing the folowing procedure!!
9. Using a 5/16'' wrench or deep well socket, remove the 2 nust holding both fuel rails down.
10. Remove the intake plumbing. PITA i know, but it is well worth it.
11. Lift gently and evenly on the fuel rail until all 4 injectors are clear of the manifold. It is a Bioch to pull, so just go slow and steady. Repeat on other rail.
(there is no need to releave the fuel pressure, you will still spill fuel, just let it drain on the motor, it will evaporate in a minute)
(And, duh... I know most people don't work on their engine after cruising the interstate for hours, but if you do, please do this when the engine is sorta cool so you don't blow up.)
12. Visually inspect the injector, don't clean it yet even if it is dirty or looks clogged.
13. Switch it with an injector from the other side of the engine.
14. re-install everything and start it up. See if the misfire followed the injector. IF it did, clean or replace the injector. If the misfire is STILL at cylinder #5, then your only possible causes left are:
1. The sparkplug (you said you checked these already)
2. mechanical problem within cylinder #5
3. the connector or wiring to cylinder #5's injector or coil
Hope this helped. IF you follow this without cutting corners, you WILL find your misfire.
Note that a multiple cylinder misfire should be aproched using this same method, just make sure when you go to swap coils and injectors, you are swaping with known working cylinders.
-Steve
You won't be able to run your car WOT, trust me. Replace your plug wires, i can pretty much guarantee that is the problem. The same thing that is happening to you happened to me a few weeks ago, everything is the same. I bought some Ford racing 9mm wires and drove it after that, it ran real strong. And the old wires were stiff and had some cuts on them too.
For what it's worth, I had a very very similar problem on my 98 about a year ago. Twice in fact. I went through the whole process of replacing the plugs, wires, and fuel filter.
I'm just now learning to do the work myself. At the time, I took her in to my mechanic and he ran some sort of cleaning process on the fuel system. He basically said that while the computer SHOULD be able to handle the crappy gas some places sell, a lot of cars will have trouble with it and that basically my Stang's fuel system was getting clogged up on the non-detergenated gas that some places sell.
Anyway, after the new plugs, fuel filter, and the injectors cleaned by him, I've always used the same place for gas and I've not had a problem since.
I'm just now learning to do the work myself. At the time, I took her in to my mechanic and he ran some sort of cleaning process on the fuel system. He basically said that while the computer SHOULD be able to handle the crappy gas some places sell, a lot of cars will have trouble with it and that basically my Stang's fuel system was getting clogged up on the non-detergenated gas that some places sell.
Anyway, after the new plugs, fuel filter, and the injectors cleaned by him, I've always used the same place for gas and I've not had a problem since.
Rickey_Bobby
New Member
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