How to check if injectors are firing?
#1
How to check if injectors are firing?
Like it says, how do I test to see if the injectors are firing?
...I'm having my no-start issue yet again. It's happening more frequently now. I have the correct fuel pressure, and I'm wondering if maybe the injectors aren't even firing.
...I'm having my no-start issue yet again. It's happening more frequently now. I have the correct fuel pressure, and I'm wondering if maybe the injectors aren't even firing.
#2
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Car: 92 Z28
Engine: Boosted LSX
buy a noil light. it plugs into the injector harness and blinks of they are getting power.
http://www.etoolcart.com/browseprodu...ht-NM5559.HTML
http://www.etoolcart.com/browseprodu...ht-NM5559.HTML
#4
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Car: 1997 Jeep Wrangler
Engine: 4.0L
Transmission: 5 speed
Axle/Gears: 8.8 rear, 4.56 gears, 4:1 transfer
A noid light will not tell you an injector is firing fuel. It will only tell you the ecu or distributor is commanding fuel. The only way to tell if an injector is actually firing is to remove the fuel rail or do the "leakdown" check per the GM manual.
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Car: 92 Z28
Engine: Boosted LSX
Originally posted by John Millican
A noid light will not tell you an injector is firing fuel. It will only tell you the ecu or distributor is commanding fuel. The only way to tell if an injector is actually firing is to remove the fuel rail or do the "leakdown" check per the GM manual.
A noid light will not tell you an injector is firing fuel. It will only tell you the ecu or distributor is commanding fuel. The only way to tell if an injector is actually firing is to remove the fuel rail or do the "leakdown" check per the GM manual.
#7
To find an individual injector gone bad, I'd understand the leakdown test, but this is for my no-start problem. Assuming that I am actually getting the inector pulse, what are the chances of multiple injectors all with the same intermittent failure.
Almost non-existant.
...I just re-read my post and realized that you guys may not be familiar with my problem. I'm having trouble with the car not starting. I'm trying to eliminate the possibility that for whatever reason, the injectors aren't being told to fire. The noid light with do that for me. I realize that it will not find a bad injector.
Almost non-existant.
...I just re-read my post and realized that you guys may not be familiar with my problem. I'm having trouble with the car not starting. I'm trying to eliminate the possibility that for whatever reason, the injectors aren't being told to fire. The noid light with do that for me. I realize that it will not find a bad injector.
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#8
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Just dso you know one shorted out injectr can kill either a whole bank of them or maybe both banks due to it shorting the driver in the ECM. If it wont start first check spark and injector fire and see which your loosing.
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Car: 1997 Jeep Wrangler
Engine: 4.0L
Transmission: 5 speed
Axle/Gears: 8.8 rear, 4.56 gears, 4:1 transfer
Originally posted by Abubaca
To find an individual injector gone bad, I'd understand the leakdown test, but this is for my no-start problem. Assuming that I am actually getting the inector pulse, what are the chances of multiple injectors all with the same intermittent failure.
Almost non-existant.
.
To find an individual injector gone bad, I'd understand the leakdown test, but this is for my no-start problem. Assuming that I am actually getting the inector pulse, what are the chances of multiple injectors all with the same intermittent failure.
Almost non-existant.
.
#13
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Car: 1997 Jeep Wrangler
Engine: 4.0L
Transmission: 5 speed
Axle/Gears: 8.8 rear, 4.56 gears, 4:1 transfer
The distributor ignition module fires the injectors under 350rpm (during cranking), after that the ecu takes over control of the injectors.
If you have a cheap parts store ignition module in your distributor get it out now and replace it with an AC Delco module. Don't forget the special greese under it or even the Delco one will fry.
This may of may not fix your problem but it is good insurance.
If you have a cheap parts store ignition module in your distributor get it out now and replace it with an AC Delco module. Don't forget the special greese under it or even the Delco one will fry.
This may of may not fix your problem but it is good insurance.
#14
Not true. I had a complete set of 8 fuel injectors I bought from Street and Performance. All of them were bad.
The distributor ignition module fires the injectors under 350rpm (during cranking), after that the ecu takes over control of the injectors.
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Car: 91 GTA, 91 Formula, 89 TTA
Engine: all 225+ RWHP
Transmission: all OD
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Bad injectors will funtion until the driver(inj driver) board overheats and shuts down :-) Once it cools it will refire.
Other fun things are pickup coil in the distrib and the module.
When these dont outirhgt fail, they tend to act up in overheat/high tempature conditions first and then die completely.
(or cause weak pulse/signal to ecm resulting in weak spark and/or intermittnet injection)
Other thing is Vats issues. Dirty and worn key or ign lokc barrel or even broken or intermittent wire connections there. Possible module too, but I havent seen a moduel fail in my own experience.
later
Jeremy
Other fun things are pickup coil in the distrib and the module.
When these dont outirhgt fail, they tend to act up in overheat/high tempature conditions first and then die completely.
(or cause weak pulse/signal to ecm resulting in weak spark and/or intermittnet injection)
Other thing is Vats issues. Dirty and worn key or ign lokc barrel or even broken or intermittent wire connections there. Possible module too, but I havent seen a moduel fail in my own experience.
later
Jeremy
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Car: 1997 Jeep Wrangler
Engine: 4.0L
Transmission: 5 speed
Axle/Gears: 8.8 rear, 4.56 gears, 4:1 transfer
Originally posted by Abubaca
[B I've replaced the module, but it was NOT AC delco. It worked fine for awhile, then the problems came back. ...but of course it could be coincidence. . [/B]
[B I've replaced the module, but it was NOT AC delco. It worked fine for awhile, then the problems came back. ...but of course it could be coincidence. . [/B]
The only other thing in the crank fuel system is teh pickup coil and wireing between the ignition module and ecu. The ecu injector drivers don't come into play untill the engine is started (over 350rpm's).
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Car: 1982 Z28
Engine: LS1
Transmission: T56
Originally posted by Abubaca
I'm gonna pick up an ACDelco mod. this week. I won't get to do much more "testing" till the weekend though.
Thanks!
I'm gonna pick up an ACDelco mod. this week. I won't get to do much more "testing" till the weekend though.
Thanks!
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