injector help

[2deuce]

If there is one injector that isn't working properly out of the total 8, how can you find it? Is that possible?
Thanks,
Greg

 

[ODdave]

what is it doing that makes you think it isnt working?

 

[kipman]

Loosen injector lines untill you find the problem.

 

[ODdave]

 

[2deuce]

I'm trying to find out why my M1009 idles rough. I was thinking that possibly it was an injector and since the idle has gotten worse maybe more than 1. I checked the return line glass bead and that was good. I listened to all of the injectors working and couldn't tell any differences between them. I can feel the miss at the tail pipe on both sides, it is random, no discernable pattern. The truck runs fine once your off idle.

Thanks,
Greg

 

[dstang97]

or you can have them all pop tested and see if they are any good.

 

[T_F_E]

Is you idle set to low?

 

[2deuce]

I increased the idle last year, it helped some, but it has gotton much rougher lately. Could the injectors be dirty and cause this? On the interstate the truck runs smooth but likes to speed up and slow down about 5mph on its own. Does it most at 60 mph. When I come off the freeway to a idle it wants to cycle like a cold lawnmower engine until I give it some throttle. Like it isn't getting enough fuel for the throttle setting. Could the mufflers be clogged creating too much back pressure? I don't think its pulling air as it starts easily.
Can someone explain indirect injection in this engine?
Thanks

 

[2deuce]

Forgot to add I never see smoke from the tail pipe after its warm.

 

[dmc-4359]

With pictures no less;

How Cars Work - Sections of Vehicle - Indirect and Direct Fuel Injection Systems

 

[2deuce]

Thanks for the link, I was surprised to see you get more power with indirect.

I think I found my problem with the rough, irregular idling. I went for a drive and while I was pulling up to a stop sign I felt the gas pedal move or click and the truck went into a very rough idle from just a rough idle. I had felt this happen before. I removed the green wires off the IP and the truck now idles smooth. I first only removed the fast idle wire, but I figure the other wire should be disconnected also since they both are getting the wrong signal. It idles great now. I'll see how the next cold start goes.

 

[T_F_E]

You can get more power from direct because you dont need to have the high compression so you can add more boost.

 

[Shop Rat Fab]

Heat sensing temp gun on the exhaust manifold works too, if you have one, look for the coolest cylinder.