got a miss

chris2523

chris2523

93 Mark VIII
Joined
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so my car has a miss. i noticed it friday.
slightly rough idle and a slight hesitation right off idle. pulls cleanly in all gears, but feels down on power.

ran the codes. didn't find anything relevant. some IAT and MAF codes from when i had the intake tube off.
removed my chipped computer and the problem remains.
chip problems eliminated.
code check on the new comp revealed a 111 after some drive time.

cylinder balance test gave me an 8, 8, 9.
so my problem lies in cylinder 8. unplugged the fuel injector and restarted. yep. not much change.
plugged 8 back in and pulled injector 7. everything got much worse.

so tomorrow i'm gonna pull the plug and wire on 8 and see what's up.
if the head gasket is leaking i will see a clean plug correct? since its like being steam cleaned.

i am low on coolant occasionally, but that's nothing new. its always been that way.

i know these cars have head gasket problems around cylinders 7 and 8 so i'm kinda worried.

anything else i need to check? it really ran pretty great right before this.
 
My gen1 did this when the wires went bad, get some good wires first and see if it does the trick.

I doubt its a head gasket, won't hurt to look at the plug.
Missing coolant makes me think water pump or oil filter adapter to block gasket.
I am sure you will figure it out.
 
you need an injector. god i hope it is not the head gasket, that wouldnt make much sense.
 
Mine had a miss kind of like how yours from how it sounds, I replaced the wires and one coil pack so far most of the miss is gone. Only difference I see is I have no hesitation and it still has power.
 
pulled injector 8.
the little pin that sticks out on the other injectors wasn't sticking out the bottom and it felt warmer than the other injectors.
internal short maybe?
anyway, pulled another blue top 28 # from the 69 cougar and put it in.
runs much better. not perfect though. i'm gonna pull the rest of the injectors next week.
the injector looked different. 4 holes in the tip instead of 1. i'll blame what's left on a mismatched injector for now.
 
Sorry for being a thread hijacker, but is this cyl 7 & 8 head gasket issue a common problem with the MK8. I read these motor are bulletproof so I guess not, but how do I prevent it from happening?
 
DonDotta said:
Sorry for being a thread hijacker, but is this cyl 7 & 8 head gasket issue a common problem with the MK8. I read these motor are bulletproof so I guess not, but how do I prevent it from happening?
Click to expand...

these motors are good. but nothing is "bulletproof."
don't overheat it and your good to go. the aluminium block and heads don't like all the heat.
 
chris2523 said:
these motors are good. but nothing is "bulletproof."
don't overheat it and your good to go. the aluminium block and heads don't like all the heat.
Click to expand...


Yea your absolutely right, and I already know about aluminum engine when they overheat. My old acura 3.5RL had an all-aluminum engine, and blew a head gasket quickly after overheating, and it was a very reliable motor.

I asked that because you said it they had issue with HGs blowing.

EDIT: Oh I just read that your cylinder 8 was misfiring. Ok I now see where that came from. Sorry about that it's getting late :)
 
lol. right.
the only reason i was concerned about the head gasket was because cylinders 7 and 8 is where it gives out. that area has less cooling and oil than the rest of the head.
 
have you ever noticed any drips under the radiator? I've had bad luck with these cheap ass radiators leaking in the past. My old 97 thunderbird went through 2 radiators, and my current 95 mark will be getting a new one soon as well. They like to leak from the side tanks where the tank is sealed to the aluminum core. My mark now has a slow leak from where for the trans cooler lines meets the plastic tank...so I wouldn't jump to the conclusion that you are losing coolant due to a head gasket, or at least i hope for your sake it's not a head gasket :/
 
yeah i've seen alot of these plastic side tanks leaks. but i have never found any coolant drips anywhere.

i replaced all the fuel injectors with a low mileage set of the newer style 24 # injectors.
the miss is gone and all my power is back. i had more than one marginal injector apparently.
multiple failure = weird.
 
Last edited:
chris2523 said:
yeah i've seen alot of these plastic side tanks leaks. but i have never found any coolant drips anywhere.

i replaced all the fuel injectors with a low mileage set of the newer style 28 # injectors.
the miss is gone and all my power is back. i had more than one marginal injector apparently.
multiple failure = weird.
Click to expand...

28# i thought they were 24# unless you have changed yours or gen 1 had 28#?
 
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