Wierdo miss from engine, never heard of this
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Joined: Oct 2005
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From: Waldorf, MD
Car: 91 Formula, 89 IROC
Engine: LB9, LB9
Transmission: 700R4, 700R4
Axle/Gears: Posi 2.73, Posi 2.73
Wierdo miss from engine, never heard of this
Well guys the miss (I guess) from my LB9 makes it run rough and have less power. I pulled each wire off of the distributor while the engine is running and ALL of them made a difference in idle and how the motor ran. Wouldnt at least one of them be completely dead for there to be a miss?
Thread Starter
Senior Member
Joined: Oct 2005
Posts: 874
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From: Waldorf, MD
Car: 91 Formula, 89 IROC
Engine: LB9, LB9
Transmission: 700R4, 700R4
Axle/Gears: Posi 2.73, Posi 2.73
Re: Wierdo miss from engine, never heard of this
Well guys I did an injector resistance test and it went like this...
Cylinder #1: 5.1
Cylinder #2: 16.9
Cylinder #3: 16.8
Cylinder #4: 16.8
Cylinder #5: 17.1
Cylinder #6: 16.8
Cylinder #7: 16.9
Cylinder #8: 17.0
Ok guys I do realize that injector #1 is low, so with it running I unplugged the injector and it did idle noticably rougher with a big stumble within 10 seconds.
The readings came from an engine that had sat for 3 hours without running, but it was not cool to the touch, and also when I went to run the engine to disconnect #1, it was not running as rough as usual.....it kinda has fits and runs rougher when warm sometimes.
What can you guys tell me from this info? Any help would be greatly appriciated.
Cylinder #1: 5.1
Cylinder #2: 16.9
Cylinder #3: 16.8
Cylinder #4: 16.8
Cylinder #5: 17.1
Cylinder #6: 16.8
Cylinder #7: 16.9
Cylinder #8: 17.0
Ok guys I do realize that injector #1 is low, so with it running I unplugged the injector and it did idle noticably rougher with a big stumble within 10 seconds.
The readings came from an engine that had sat for 3 hours without running, but it was not cool to the touch, and also when I went to run the engine to disconnect #1, it was not running as rough as usual.....it kinda has fits and runs rougher when warm sometimes.
What can you guys tell me from this info? Any help would be greatly appriciated.
Thread Starter
Senior Member
Joined: Oct 2005
Posts: 874
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From: Waldorf, MD
Car: 91 Formula, 89 IROC
Engine: LB9, LB9
Transmission: 700R4, 700R4
Axle/Gears: Posi 2.73, Posi 2.73
Re: Wierdo miss from engine, never heard of this
but wouldnt it not make a difference in running if it was bad and I pulled the wires from it?
Joined: Feb 2002
Posts: 3,462
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From: N. Illinois
Car: 92 GTA/ 00 TA
Engine: 383/350
Transmission: 700R4/T-56
Re: Wierdo miss from engine, never heard of this
It's still shooting it's load just not the way it's supposed to.
It's time to replace the injector.
It's time to replace the injector.
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From: Chasing Electrons
Car: check
Engine: check
Transmission: check
Re: Wierdo miss from engine, never heard of this
They are probably the stock Multec injectors. With one failed the others are right behind it. Best bet is to get a set of Bosch 19#'ers and replace them all (and the o-rings).
RBob.
RBob.
Thread Starter
Senior Member
Joined: Oct 2005
Posts: 874
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From: Waldorf, MD
Car: 91 Formula, 89 IROC
Engine: LB9, LB9
Transmission: 700R4, 700R4
Axle/Gears: Posi 2.73, Posi 2.73
Re: Wierdo miss from engine, never heard of this
I was gonna go for some ford racing 19 pound injectors because they are probably the same price. Were the injectors in 1991 the good ones or the trashy ones?
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From: Chasing Electrons
Car: check
Engine: check
Transmission: check
Re: Wierdo miss from engine, never heard of this
GM started using the Multec's in '89. And continued past '92 with the LT1's and on until ??
They typically die from the coils shorting out, which is what the 1 injector shows.
RBob.
They typically die from the coils shorting out, which is what the 1 injector shows.
RBob.
Thread Starter
Senior Member
Joined: Oct 2005
Posts: 874
Likes: 0
From: Waldorf, MD
Car: 91 Formula, 89 IROC
Engine: LB9, LB9
Transmission: 700R4, 700R4
Axle/Gears: Posi 2.73, Posi 2.73
Re: Wierdo miss from engine, never heard of this
Ok guys so this can cause loss of power, chugging, and rough idle?
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From: Central Arizona
Car: 1985 IROC
Engine: 305 TPI
Transmission: T-5
Axle/Gears: Wish it had 3.73's...
Re: Wierdo miss from engine, never heard of this
Yup...my '85 IROC did the same thing several years ago. It would start to miss about 10 seconds after idling, but it was very faint. After testing the injector by watching the fuel pressure and triggering the injector, it was causing the cylinder to run lean. That's why it was very faint. I bought a set of Accel injectors and it has run great ever since.
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