94.5 Missing

powerjoke4life · Jul 7, 2014

I just picked up a 94.5 cclb 5 speed. It's idles rough and has a serious miss until about 1500 rpm when it seems to smooth out but still low on power (yes I know the 7.3 is a dog but it's extra slow) the truck is all stock and I know it needs injector rings. It smokes some white at start up and I will be changing those this weekend but I think it's an injector issue. What's this buzz test I have been reading about? How do I test the injectors so that I don't have to pull them twice. I don't wanna put new rings in just to have to pull the injectors again and put new ones in. I'm also gonna run a few tanks of rev x or the likes through, is rev x the best or do you guys suggest something else?

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Arisley · Jul 7, 2014

Buzz test checks the injector solenoids and associated wiring.

Best bet is to pull the injectors and have them checked by a good shop.

How many miles on these injectors, if you have no clue, assume it is the same miles as the truck. If it has a lot of miles on it, just get some new injectors.

powerjoke4life · Jul 7, 2014

Arisley said:
Buzz test checks the injector solenoids and associated wiring.

Best bet is to pull the injectors and have them checked by a good shop.

How many miles on these injectors, if you have no clue, assume it is the same miles as the truck. If it has a lot of miles on it, just get some new injectors.

So buzz test is just making sure they are getting power and signal?

Truck has 210k on it and I would assume they are original, how many miles should I be able to get out of injectors?

I can run and have them inspected, I was hoping that there was a way to see if they were bad without pulling them. That way I could order all the parts I need and knock it over the weekend. But it sounds like without pulling them I won't know.

Boy the wife is going to be excited to hear I have to "Fix" my injectors with some 160's lol

Justin@DP-Tuner · Jul 7, 2014

200k miles out of injectors is about the norm. Some go many more with great maintenance, while some go much less with bad maintenance. At 200K there is going to be wear regardless though.

The white smoke at start-up is a telltale sign of either worn injectors, a problem in the GP system, or low compression. In your case it sounds as if the injectors are going to be at fault.

powerjoke4life · Jul 7, 2014

Justin@DP-Tuner said:
200k miles out of injectors is about the norm. Some go many more with great maintenance, while some go much less with bad maintenance. At 200K there is going to be wear regardless though.

The white smoke at start-up is a telltale sign of either worn injectors, a problem in the GP system, or low compression. In your case it sounds as if the injectors are going to be at fault.

It also has low compression :doh: If I didn't get such a good price I think I woulda ran from it. Should get a motor build this winter but lets get it running good first.

I will dig into and let you guys know what I find.

Patrick Feeley · Jul 7, 2014

You could always measure the injector armature plate clearance. You remove the injector solenoid and then check clearance between the injector body and armature plate (the plate with the screw in the middle). New is around 0.004" and below 0.002" is getting towards the end (some of the ones on my 94 were down to 0.0015"). Also make sure that the poppet screw (the middle screw) is tight. They like to loosen up and cause a nice miss. Cheers!

powerjoke4life · Jul 8, 2014

Patrick Feeley said:
You could always measure the injector armature plate clearance. You remove the injector solenoid and then check clearance between the injector body and armature plate (the plate with the screw in the middle). New is around 0.004" and below 0.002" is getting towards the end (some of the ones on my 94 were down to 0.0015"). Also make sure that the poppet screw (the middle screw) is tight. They like to loosen up and cause a nice miss. Cheers!

Awesome thanks that is very helpful, I will let you know the results in a couple days.

powerjoke4life · Jul 11, 2014

Injector #1 on the passenger side is out. I will be getting some 160s here soon but to get my by for a couple weeks I need one single shot injector. Does anyone have a good oem one they want to sell?

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