Testing fuel injectors? How?

What does he think is wrong with the injector?

Electrically, you can test the resistance.

For leakage, you can remove the injectors and fuel rail as an assembly, run the fuel pump, and wait.

For clogging, well, depending on the injector, hard to find.

If you have a misfire on a specific cylinder, you could swap the injector with another cylinder and see if the misfire moves to that cylinder.

The injector isn't opening all the way. I'm getting a 'lack o'fuel' miss. Basically a miss but no gas smell out of the exhaust. What's the best way to test resistance?

Not sure mortal man has the equipment to properly check an injector. I thought they should be around 12 ohms but that's only one check. They can have the right resistance buy still be partially clogged. How much do you trust your mechanic? If you want to DYI, I solved a misfire problem in a 98 Montana by installing a set of reconditioned injectors from

There's a bunch of places selling recond. injectors but I read of this outfit on another board. Not sure of cost for the 3.1 but it was around $150 +/- for the 98.

The problem is that I don't have the funds to replace all the injectors at once. For 6 @ 70.00 (for new) That's almost 500.00 :( I don't plan on having the car much longer.

Hmm ... seems really cheap for an injector at that place ... How long have you had those injectors?

Replaced them in Jan 04 & about 6000 miles ago.

but your going to pay 300 to have them looked at? then replaced if nessacery?

Your mechanic may be right but if you want to try a cheaper solution, here is one. Get a good fuel injector cleaner, I use Marvel Mystery Oil. Get on the interstate & run it out. Try to keep an average speed of 70-80 mph. Run at least 100 mi. That may take 1 hour 15-20 min but you should see some improvement if the injector is only clogged. If that is the problem all of the injectors should need cleaning.

You check the injector's resistance by disconnecting the connector from the injector and measuring the resistance of the injector across its two pins (on the injector, not the wire) with a digital multimeter. I don't know if I'd trust an analog ohmmeter, but I suppose it should work.

I'd go the swapping injector route. Find out which cylinder is misfiring, swap that one injector with another cylinder, and see if the misfire moves. If the injector is "not opening fully" as alleged, the resistance check should still be good.

Not to pick a nit but that's just over 400 dollars (420). I'm sure your point still stands on that anyway though.

Already paid 250 to have my 'miss' looked at ...

Been there .. done that :)

hehe .. 420.00 plus gaskets, bandaids, and money for the cuss jar = $500.00

Thanks Don. I'm gonna give em a whirl if they reply to my email.

Using that stuff as we speak. We'll see what the mystery stuff will do.

If someone charged you that:

Then told you it was an injector. With all due respect, you were "BUNGHOLED!"

Refinish King

PS What ever happened to customer, not servicing the customer?

How about this: yank one plug at a time and bend the electrode shut, shorting it out. Put it back in and run engine, if it runs worse, obviously not that cylinder, move plug to next, etc. until you find the suspect cylinder/injector and service just that one. Comments?? Tom