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2000 GT, Idle flucuates between normal and around 300rpm
My car has been some tough times the last couple weeks, first the fuel pump died, replaced it, then a week later the intake manifold decided to crack which drenched the engine with coolant (literally), I had the intake replaced and very shortly afterwards started having misfire issues, The car was throwing P0354 code so figured cylinder 4 was the problem.
Well long story short cylinder #1 had some coolant in the sparkplug well which was causing that COP not to fire, I dried the well out and now the car is pretty much running great except for one new symptom, the car doesnt want to idle properly..on a cold start it idles fine but after the car warms up it wants to idle at around 300 rpm (Barely running) and it will fluctuate between normal idle and 300rpm randomly. I checked all the hoses (Since I had some of them off when pulling out all the COPS) but the hoses look fine.
Would unplugging the MAF sensor cause this symptom? I unplugged the MAF briefly because I was going to clean it but then realised I didn't have the proper "safety" torx20, it seems the idle issues started after this. (I never actually took the MAF out, only unplugged the harness for a few minutes).
Engine is all stock (minus clutch) w/ 75k miles.
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Do you have a means to check either narrowband (via OBDII-Datalogger) or wideband (via wideband AF gauge) air/fuel ratio? That can usually be helpful is situations like this.
Do you have a means to check either narrowband (via OBDII-Datalogger) or wideband (via wideband AF gauge) air/fuel ratio? That can usually be helpful is situations like this.
I don't but I know someone that might be able to do it for me.
I haven't tried disconnecting the battery I wasn't aware this might help. Guess its worth a try.
Thanks, It seemed to of helped but something still not quite right, when I come to a stop it likes to drop down into 400'ish rpm range then up to normal but at least now it stays at normal idle instead of fluctuating back and forth, But I also notice when I take off it seems I have to give it more gas & clutch to have a smooth take off, otherwise it sort of "falls flat", perhaps I should trying cleaning the MAF and IAC see what happens.
Thanks, It seemed to of helped but something still not quite right, when I come to a stop it likes to drop down into 400'ish rpm range then up to normal but at least now it stays at normal idle instead of fluctuating back and forth, But I also notice when I take off it seems I have to give it more gas & clutch to have a smooth take off, otherwise it sort of "falls flat", perhaps I should trying cleaning the MAF and IAC see what happens.
Man, that is EXACTLY what my car did when I had an issue with my timing. On startup it idled and felt perfect, but when it heated up the idle would drop super low (~400 RPMs, mine is set for 800), and I lost a lot of power at low RPMs when accelerating. It seemed to "fall flat" exactly like you described it.
My issue was with my timing, but since you had problems with your spark system (coolant and the like) I would be very confident that the problem lies somewhere in there. I would start by changing out your plugs, as getting coolant all around it can't be good. From there, test the COPS to make sure you're getting spark.
Like I said, this sounds exactly like my problem when my timing was too far retarded. Given what happened to your engine, I would start there.
Man, that is EXACTLY what my car did when I had an issue with my timing. On startup it idled and felt perfect, but when it heated up the idle would drop super low (~400 RPMs, mine is set for 800), and I lost a lot of power at low RPMs when accelerating. It seemed to "fall flat" exactly like you described it.
My issue was with my timing, but since you had problems with your spark system (coolant and the like) I would be very confident that the problem lies somewhere in there. I would start by changing out your plugs, as getting coolant all around it can't be good. From there, test the COPS to make sure you're getting spark.
Like I said, this sounds exactly like my problem when my timing was too far retarded. Given what happened to your engine, I would start there.
Sorry I'm a bit of a newbie with these 4.6 engines, How does one even adjust the timing and what factors would've caused it to slip out of proper timing?
Sorry I'm a bit of a newbie with these 4.6 engines, How does one even adjust the timing and what factors would've caused it to slip out of proper timing?
My fault, I must not have been clear.
What I meant was, my problems were exactly the same when I had too little spark. Since you had coolant in your spark system, it seems to me that your problems could be caused by a malfunction in your spark system (since the symptoms were the same as mine).
I wasn't necessarily suggesting that your timing got out of whack, but merely that something is wrong with your spark system.
My suggestion was to go back to basics and make sure that your spark plugs and COPS all work perfectly. Your coolant leak leads me to believe that something is causing your spark system to fire either not often enough or erratically, thus causing your car to behave like it is.
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2000 GT, Idle flucuates between normal and around 300rpm
