I don't normally post links to stuff on ebay, but there is a really nice Injector Performance Analyzer that is selling for less than half of the cost of a new one.

Go to ebay and search "injector analyzer" and you'll see it.

It is not mine, I do not know the seller. I do however have all the pieces to make one and will someday when my next injector fails. Have a good weekend tearing your trucks apart!

 

you have all the pieces needed to make one of those? do you own a Lowes?

 

I used to have a link with instructions for building an injector breakout box. It would be handy to have, but $400 for a tool you may need twice in your life seems like a lot.

 

hey hey, share the wealth. I'm trying to check my injectors. anyone know of a way for me to check them without expensive equipment? if so I'd love plans/schematics. I love homebrew stuff on the cheap.
Chead

 

You can do a psuedo injector test by doing a cylinder contribution test. All the tuners, Diablo Predator, SC tuner, Superchips, etc have that capability in the diagnostics section. The weakest injectors will have the greatest rpm drop. I used mine in that way to diagnose a weak number 4 injector.

 

Wouldn't the weakest injector have the least rpm drop?

 

No, because each injector does it's part to maintian engine rpm. When there is a weak injector or a dead miss, then the engine relies on momemtum of the flywheel to take it to the next cylinder in the firing order where the idle speed is restored. So it's easy to pick out a weak cylinder that way because there is an easily measured drop in crankshaft speed for that cylinder.
When I went to school to learn all this stuff it blew me away how fast the processors are, even back in the '80s. They are able to manage and measure engine operation down to 1 degree increments of the 360 degrees of the turn of the crankshaft while the engine is running.

 

well I'm pretty sure one of my injectors gave up the ghost but I have no tester. started the process of pulling them. gonna call the local injection shop and see if they can help test them out of vehicle. I can't even move the stupid thing to a shop if I wanted to, and don't feel like paying for a tow. got another vehicle for work, but need this one running in like 2 weeks. we'll see what happens.
Chad

 

List of parts needed (at least)

42 Pin Connectors, Male and Female
8 Toggle Switches 120V 10amp min
Controller box, I got mine from Radio Shack
16 gauge wire, 100 ft of Red and 100 ft of black
8 feet of 3/4 wire loom
1 ft of 1 inch wire loom
Electrical tape
Connectors for switches
Shrink tubing

I got my 42 pin connectors at a Lincoln Mercury dealership for free. They were from old, bad harnesses. Connectors look great. They are used on a lot of FoMoCo products, not just SD's and Excursions. See pic below for one side of the connectors.

PM me with your email address and I'll email you a copy of the instructions in PDF format. That goes for anyone reading this.

Andy

 

I have a SCMT1705.Can this tuner be used to diagnose which injector is weak? Is there a simple and cheap way? Ford wants over $127.00 for a CCT. Can you help me?
Thanks

 

I don't know for sure but if you plug it in and go to "diagnostics" or whatever the SCMT calls that sort of thing, you might be able to scroll down to a % of RPM drop for each cylinder. That's the contribution test. The weakest cylinder will have the highest number. On my Predator it's under "diagnostics" and then "diesel fuel"

 

I was with BowDown on my thinking on this but I think I've got it now. I thought the contribution test would disable each injector and measure the results on and off, and come out with a number like the old gasser spark plug wire test. This is how the break out box works correct?

So if I have it correct now, the tuners just measure the running performance, right?

 

The Cyl Cont Test pointed to my #8 injector when I had one go bad. A Break Out Box correctly identified the #6 as the culprit after I replaced #8 to no avail. From that point on I have pretty much just tried to forget everything I ever knew about the CCT... There's something about doing a big job like replacing an injector for no reason that just makes you wanna disregard the whole test.

You plug the break out box in-line in the 42 pin connenctors and can manually flip the switches one at a time while driving up an incline and either watch your Mass Fuel Demanded fluctuate on your AutoEnginuity or equivalent, or feel how bad it runs in each position, or both. You can also do it at idle but apparently it's easier to diagnose while driving.

I haven't made my Break Out Box yet because my truck hasn't lost an injector since that one several years ago. I have all the parts. Just start looking for the male and female 42 pin connectors and you can make the device. I got my connectors for free at a Lincoln Mercury dealership that I had previously never walked into. Just talked to the service manager for a second and told him what I was going to do. He took me way across the parking lot to a back shed where there were a bunch of harnesses that had been taken off cars. You just need the connectors and if you're lucky like 6 inches of wire with each one.

www.mass-air.com has new pins for the connectors.

 

does any one have a picture. I'm words dumb. picture smart.

 

PM me your email address and I will send you the writeup with pictures. If you are picture smart, then you'll be a genius after looking at these!