Anyone know of a way to diagnose a bad injector other than going to the ford house?

Bowedup

 

It's messy but you could unplug and then plug back in each one individually as the engine is running until you find the offending injector. It has to be done with the valve covers removed so a lot of oil will get spilled while the engine is running.

 

is there a check engine light? could scan it if its an electrical problem. and kwik is right about how to check each individually but i have run them before with out valve covers and the oil doesn't make a mess much to my surprise.

 

What about the high voltage warnings on the valve covers? Can you get shocked by unplugging the injectors while the engine is running?

 

Yeah it's high voltage. The safest way is to go pay for the diagnostic. Otherwise your stuck with thick rubber gloves.

 

you can pull the vc's and start it and watch the oil spouts to see if oils coming out of each injector. or find someone in your neck of the woods who can do a cylinder contribtuion test for you.

where do you live?

 

You can use an "injector break-out-box" or go to a diesel shop that has one and they'll electrically disconnect each one until the bad one is diagnosed. Both Ford and the local diesel shop quoted me $150 for this service. After changing my #8 injector (because it showed up as the bad one on my Cylinder Contribution Test) and that not being the bad injector, I decided this was the better course of action for me. Since then, I have rounded up all the parts needed to make my own injector B-O-B, but I'm working 100 hrs a week right now and the truck runs sweet.

 

Whew, 150 for contribution test, a couple of test and you could get some auto enginuity software and test them all day long.

 

Sorry I was not clearer. The $150 is for the injector break out box test, not a CCT. I have the A.E. and have run the CCT many times. It's two different things. The break out box puts a switch in each injector circuit so you can manually turn off each injector. You turn off each injector, watch the "Mass Fuel Demanded" on your A.E. and also confirm with the feel of the engine. The injector that makes the least difference in the MFD and feel of the engine is the culprit. My A.E. had ID'd the #8 as being bad and so I replaced it. The engine ran exactly the same. The B-O-B test ID'd the #6, and replacing that one fixed it. The moral of the story is the CCT test doesn't always tell you the wrong injector.

To make a B-O-B, just get some 42 pin connectors, male and female, some switches, some wire and a control box to mount the switches and whip one up. I've got all my components, just waiting for time and necessity to force me to make it.

 

If you don't have access to scan tools and want to make a quick accurate diagnosis use a raytek laser thermometor and check each exhaust manifold at the same place on each port. Compare the temp readings. Typically a bad injector will give you a colder reading than a good cylinder, although it is possible to have a reading that is higher than the others if the injector is dumping fuel intot the cylinder, (injector tip blown off/cracked).

 

I am not sure but if I was guessing it may be a tip problem because I have noticed that lately when I stomp it I can pour a good thick stream of smoke out, even at 18-20psi boost.

Bowedup

 

I tried this on my truck this weekend. All of the cylinders were within 1 or 2 degrees of each other except one, which was 10 degrees low. Is that enough to say its bad? It was the front passenger side port. Which cylinder is that? Does a bad injector tick like a lifter noise?

 

LOL... Don't they all tick?

 

Anyone thought of making these B-O-B's and selling em?

 

You can buy one from Mission Valley Ford in San Jose, CA for about a grand...