Help 7.3 missing, no codes, did buzz and contribution tests

[Probuilder]

number 8 has almost no change to the engine. But the rest cause the motor to slow down and miss worse. So does that mean that the #8 injector is bad?
Also this truck has 342K on it. Would u just replace q injector or should I change all 8?
Can these injectors be changed out with a set from a 97 motor? I have a spare set of those laying around. So it would be a cheap fix for me. This truck is an early 99, build date of 5/98.

[907DAVE]

Yip, #8 injector bad.

As long as the injector "codes" are the same they are interchangeable.

[SICKS-O]

are 7 and 8 still giving a weak buzz? i would also do a compression test on cyl 8.

[SICKS-O]

Originally Posted by Probuilder

number 8 has almost no change to the engine. But the rest cause the motor to slow down and miss worse. So does that mean that the #8 injector is bad?
Also this truck has 342K on it. Would u just replace q injector or should I change all 8?
Can these injectors be changed out with a set from a 97 motor? I have a spare set of those laying around. So it would be a cheap fix for me. This truck is an early 99, build date of 5/98.

do cyl 7 & cyl 8 still give a weak buzz?

the engine not running much different with #8 unplugged is a good clue, but doesnt tell us if the injector is at fault. i would suggest a compression test on that cylinder before going further.

i wouldnt replace anything until you have found the cause of your problem. if you do need an injector or 2 i would only replace whats failed. 8 new injectors are BIG money.

the simple answer is no. those are single shot injectors, unless theyre from a cali model. either way doesnt matter because the flow rating is different, 97-older 7.3 = 90cc injector, 99 = 120cc injector, 99.5+ 130cc injector.

you will need an AB model injector or a long lead injector for cyl 8 (if ford offers one).

[Probuilder]

Ok so you are saying that it maybe the compression and not the injector? Even though the buzz is very dull in sound, on the buzz test?
I will try to find someone that has a compression tester for these trucks.
I have just about had it with this truck, I am looking for a 7.3L that is newer so that I get more info from the scanner, than I do with the E99 systems.

[88Racing]

Is this resolved?

[cleatus12r]

I had left a bit of a resolution on the service ticket that Troy started, but have yet to hear back about it. If you can leave this thread open for a bit, I'd like to hear back from him myself.

[Probuilder]

Cody,
I have replaced the #7 and #8 injectors, but to no avail, I still have the problem. It don't seem to be as prominent, but still has the miss. I am in the process of going back through every check that everyone suggested prior to replacing the injectors. Does anyone know what this motor should have for compression, and what is acceptable?
I am about ready to buy a bow tie, if I cant figure this out.

[Power Hungry]

We need to get you down here for a weekend and see what's going on with your truck.