Testing Fuel Injectors

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I have a 97 4.3 and suspect the injectors are going bad. Does anyone know if there is way to check or test them?
Thanks,
Dan

[Old Man]

THe problem they have is being stuck open and thats checked with a fuel pressure gauge onto the schrader valve behind the intake. Once the motor is turned off the injector should maintain a decent pressure over at least 40 PSI. Anything less is a bleed down signaling a stuck injector or leak. Once keyed on it should read 60+ and as the pedal is depressed no lower than 54 PSI. You can also remove the intake air system and TB unit and look inside at the base of the intake for very clean areas near the injector pack, this signals a leak as the fuel is keeping the intake base clean via a leak since no carbon is building up on it.
Now why do you think your having a problem for one, second do you run injector cleaner often and also when was the last time you may have cleaned the upper intake?

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Now why do you think your having a problem for one, second do you run injector cleaner often and also when was the last time you may have cleaned the upper intake?
I've got a miss about 2200 RPM and once in while it pulls a P300 multiple mis-fire code. Had it in the shop for an injector cleaning and also ran some BG 44k injector cleaner thru the system. The miss is not as bad after that but still there, also my mileage has dropped from 19mpg to 17mpg.

[nickr5208]

ive heard that using a stethoscope(yes it sounds wierd) and listening to each injector individually, you can hear if they are functioning correctly...my uncle did this to my truck and i found i had a bad injector.

[bubu]

its not weird using a stethoscope ...but its obvious you have a 4 cyl truck.... you cant do that on the 4.3!!

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I've got a miss about 2200 RPM and once in while it pulls a P300 multiple mis-fire code. Had it in the shop for an injector cleaning and also ran some BG 44k injector cleaner thru the system. The miss is not as bad after that but still there, also my mileage has dropped from 19mpg to 17mpg.

It gets really bad when the humidity is high or rainy out.
I still need to check the fuel pressure, I will do that this week-end
Any ideas?

[Old Man]

It gets really bad when the humidity is high or rainy out.
I still need to check the fuel pressure, I will do that this week-end
Any ideas?

Based on this last bit of info, I dont think its the injectors.
Random misfire codes and ability to be finicky under moisture conditions is pointing toward and electrical problem. First do check the pressure but I suspect it'll be fine. Start the thing up at nite, open the hood and rev it by hand and watch the coil sides real close. One little speck of blue on the forward side of the coil is semi normal but showing the coil is leaking. Blue flames are a coil under severe distress, thats my clue of what you said. Part 2 of the electrical that has problems damp, causes misfires and stumbles is a dirty MAF. If your running a oiled filter, this promotes this problem 10 fold. MAF's can be cleaned!!

[destructo]

Based on this last bit of info, I dont think its the injectors.
Random misfire codes and ability to be finicky under moisture conditions is pointing toward and electrical problem. First do check the pressure but I suspect it'll be fine. Start the thing up at nite, open the hood and rev it by hand and watch the coil sides real close. One little speck of blue on the forward side of the coil is semi normal but showing the coil is leaking. Blue flames are a coil under severe distress, thats my clue of what you said. Part 2 of the electrical that has problems damp, causes misfires and stumbles is a dirty MAF. If your running a oiled filter, this promotes this problem 10 fold. MAF's can be cleaned!!

Is there a way to test the coil? Other than looking for the blue flame. I replaced the coil about 3 months ago and it seemed the missing stopped, for about 2 weeks or so. I will check the MAF when I check the fuel pressure.
Thanks for the info.