Injectors bleeding down
09-14-2006, 06:26 PM
#1
Injectors bleeding down What's goin on dudes?
As some of you may know, my car has had a misfire all year long. I've been too tired of it to work on it much lately and now I am ready to get this figured out.
I do believe I have a fuel injector, possibly more than one, bleeding down. I almost know for a fact that number 3 is, as I pulled out the spark plug after the car sat overnight and the plug was clean, yet drenched with fuel.
Another reason for suspicion is that GMR Speed detected 2 bad fuel injectors, that were constantly dumping fuel. After buying a new set of injectors, and still having the problem, I am suspecting that I may have a short.
When I start the car up after it has sat whether it be over night, or for a few days, it will blow out liquid from the exhaust... FUEL!
I am looking for some guidance as to how I can test my wiring for my injectors or anything related to them that could cause this. I am planning to go to the track tomorrow night, and would like to go with a good running car that doesn't have the idle speed varying by 700 RPMs. Also getting tired of two footing it
So if you guys can point me in the right direction, it would make my day
Sorry about the rambled post.
As some of you may know, my car has had a misfire all year long. I've been too tired of it to work on it much lately and now I am ready to get this figured out.
I do believe I have a fuel injector, possibly more than one, bleeding down. I almost know for a fact that number 3 is, as I pulled out the spark plug after the car sat overnight and the plug was clean, yet drenched with fuel.
Another reason for suspicion is that GMR Speed detected 2 bad fuel injectors, that were constantly dumping fuel. After buying a new set of injectors, and still having the problem, I am suspecting that I may have a short.
When I start the car up after it has sat whether it be over night, or for a few days, it will blow out liquid from the exhaust... FUEL!
I am looking for some guidance as to how I can test my wiring for my injectors or anything related to them that could cause this. I am planning to go to the track tomorrow night, and would like to go with a good running car that doesn't have the idle speed varying by 700 RPMs. Also getting tired of two footing it
So if you guys can point me in the right direction, it would make my day
Sorry about the rambled post.
09-14-2006, 08:28 PM
#6
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The pcm "fires" them by completing a ground. You can hook up a (noid?) light to watch what they are doing.
I don't know too much about the inside of the pcm, however I do a bit of electronics repair, and could easily see how if an output tranistor shorted out, it would excite the injector continously. Talking out my butt here, but have you taken a meter to the injector plugs and see if you get a ground on the wires coming from the pcm with the key on - motor not running.
I don't know too much about the inside of the pcm, however I do a bit of electronics repair, and could easily see how if an output tranistor shorted out, it would excite the injector continously. Talking out my butt here, but have you taken a meter to the injector plugs and see if you get a ground on the wires coming from the pcm with the key on - motor not running.
09-14-2006, 08:35 PM
#7
Believe it not, I got desperate a while back and tried a different PCM lol. Same results.
I have checked for power and have it to all 8.
The grounds though... I haven't checked for that yet. I don't have a meter so I will have to borrow one. I do have a noid light and a test light though. Thank you for your input!
I have checked for power and have it to all 8.
The grounds though... I haven't checked for that yet. I don't have a meter so I will have to borrow one. I do have a noid light and a test light though. Thank you for your input!
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09-14-2006, 08:39 PM
#8
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If you think it is *not* the pcm, remove it completely. Take a test light, and clip one end to the battery positive, and test each of the ground control wires, for a short to ground. If the wiring is good, you should never see the light light up.
09-14-2006, 08:58 PM
#9
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you should be able to see if the circuit is working with a noid light, you unhook the plug from the injector (with engine off) and plug in the light. It should pulse on. have you checked the Spark plug wires and sparkplugs? have seen some plugs that look ok but are broken from the inside, i always shake them if they make a noise bad plug. it could be causing the fuel not to burn and flooding the cylinder.
09-20-2006, 09:37 AM
#11
Hey guys, I did some testing and here is what I came up with. It is mostly on another thread on fbody.com, hopefully I'm not breaking any rules by linking you to it. Please take a look and provide any insight if you could. I hope to get her fixed by Friday! Thank you.
http://www.fbody.com/cgi-bin/lt1/read.cgi?msgid=276996
http://www.fbody.com/cgi-bin/lt1/read.cgi?msgid=276996
