Stumped?
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Stumped?
87' 305 TPI. The cars running rich, and i sometimes get a code 45. I pulled the plug boots off the distributor to see which one wasn't firing. When i pulled number 8, it made no change to the engines performance. I changed the wire, the plugs are newer and i recently ohms tested the injectors (all 16.3 ohms) We tested to see if the plug was getting spark, it is. The cylinder has compression. I cant seem to figure out why the cylinder wont fire? Could it be the plug or a bad injector? Any help would be great. 
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From: Ontario, Canada
Car: 86 IROC
Engine: 350 Vortec TPI
Transmission: 700R4
Axle/Gears: BW 3.27
Re: Stumped?
Test the injector and see if it is firing, put a fuel pressure gauge on the rail and turn the key on so that the fuel pump primes then turn the key off. then get two leads from your battery and put it on the injector terminals. the gauge should go to zero because the injector pulses. if not then the injector is dead.
When you drive the car and slowly ease into the throttle does it feel like the cylinder is no firing(hesitation, no power), or does it feel normal
When you drive the car and slowly ease into the throttle does it feel like the cylinder is no firing(hesitation, no power), or does it feel normal
87' 305 TPI. The cars running rich, and i sometimes get a code 45. I pulled the plug boots off the distributor to see which one wasn't firing. When i pulled number 8, it made no change to the engines performance. I changed the wire, the plugs are newer and i recently ohms tested the injectors (all 16.3 ohms) We tested to see if the plug was getting spark, it is. The cylinder has compression. I cant seem to figure out why the cylinder wont fire? Could it be the plug or a bad injector? Any help would be great.
Thread Starter
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Joined: Oct 2009
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Re: Stumped?
I will try that in the next few days. It feels responsive, but it is only running on 7 cylinders at all times. I have yet to actually have it fire on all 8. It move, but it lugs at all engine speeds, and i cant get the idle below 1250 rpms with out it dying.
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From: Florida
Car: '87 Trans-Am
Engine: LB9 (305 TPI)
Transmission: 700R4
Axle/Gears: 3.42 or 3.73..figuring it out still
Re: Stumped?
If the ignition is testing good and you have compression and still no fire on that cylinder, it sounds like injector to me. How many miles on the motor/injectors? Stock or aftermarket?
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Joined: Oct 2009
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Re: Stumped?
Its getting a strong spark and the compression was around 135 PSI. I'm not to sure how many miles are really on the car, but it has original injectors which i think are the out of date multecs. Im gonna get a fuel pressure gauge tomorrow to test the injector.
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Joined: Feb 2005
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From: Rochester,NY
Car: 1993 Caprice wagon "Shammoo"
Engine: tpi'd 406, with P4 ebl EBL 730 ECM
Transmission: custom "4L65" swap.
Axle/Gears: 3.42:1 with posi
Re: Stumped?
if you have one or can get one, an infrared temperature gun may prove handy.
It would tell you if that cylinder is cold, by it's low reading relative to the others
They are fairly cheap at places like Harbor Freight.
Evn without preassure in the rail, you can pull the inkector connection, and quickly tap 12 volts at the injector terminals. Mine make an audible click.
No clicky.. no worky
It would tell you if that cylinder is cold, by it's low reading relative to the others
They are fairly cheap at places like Harbor Freight.
Evn without preassure in the rail, you can pull the inkector connection, and quickly tap 12 volts at the injector terminals. Mine make an audible click.
No clicky.. no worky
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