loligator

Hi all,

It seems a stock fuel injector swap with 703's is a pretty common mod. I ordered my injectors a few months ago and finally got around to doing it. Unfortunately for me, my Cherokee is now occasionally throwing code 27 which means there's an issue with at least one of the fuel injectors. It's idling pretty rough too.

Has anyone else experienced such issues after swapping injectors? I reset the PCM (by disconnecting the battery for about an hour) as the write up I followed suggested but am not sure I did it correctly.

I've read a good way to determine if an injector is faulty is to check its continuity with a multimeter. Has anyone done this before? Did it prove successful?

It's possible I could have knocked some gunk into the hole in the side of the engine block while removing/installing the new injectors. Would this cause this kind of an issue? Wouldn't the gunk eventually just burn off?

Any help would be greatly appreciated.

Thanks!

Edit:

My Cherokee is a 95 Sport with the 4.0L

yarom

Resetting the ECU takes more than just disconnecting the battery.

The sequence is documented here in quite a few places.

no rdplz

Here you go...
http://thexjguys.wordpress.com/2012/...injector-swap/

End of the article has the reset procedure. Also check to make sure each of the injector electrical connections are clean and the wires are in good shape still.

Keep us up to date as there aren't many things that it could be, but the above 2 are the easiest and most common.

loligator

beautiful! the walk thru I followed was no where near as detailed as that one. I'll try resetting the PCM when I get home (if this rain lets up). If that doesn't help, I'll check the wires and connectors. Thanks.

no rdplz

No problem. Like I said, post the results whether good or bad. Hopefully the reset will take care of it for you.

loligator

I reset the PCM last night and she ran great. This morning, however, the problems came back. She actually seems to be running worse now than before I did the reset. Still same engine codes. I took a look at the wires and there was no apparent wear. Any other suggestions?

jaygitt82

prolly got a bad injector checkthe resistance in them, make sure the screens are clean. did you get them brand new or are they used from someone

loligator

they are used, reconditioned. they're ford injectors which i find kind of odd. did ford have injectors that are 703 equivalents?

I checked the resistance and all injectors are showing 16.2 or 16.3 with the exception of one that's 15.7. I can't imagine 15.7 being that bad...

yarom

Are they marked on the side with a number that ends in 703? I knew 703s to come from Neons..

no rdplz

That's gonna be a big negative since he already stated that they're Ford's, not Bosch's. Ford's equivalent to the 703 is the 700/710 "yellow stick".

Loligator - Pull the one running at 15.7 and check to make sure the electrical port is clean. Also do a spray test to make sure it's getting an even spray pattern (PM me of you don't know how to do this).

loligator

PM sent! Yes, they're Ford 700's. Yellow sticks indeed.

no rdplz

Responded. Keep posting results.

Luke95

Going off what I read on NAXJA ford injectors can cause that with the rough idling.

Programbo

Checking with a meter may help but I've seen many bad injectors test good that way. What may be happening is that you have an injector that is stuck partly open.

loligator

thanks for the replies everyone. oddly, since I pulled the injector plugs to test resistance I haven't had any issues. it's been a few days and she's running beautifully. think I should still test the injectors as recommended above? when I removed the plugs, they certainly weren't easy to come off so I can't imagine a poorly seated plug but I guess anything is possible.

I'll have to look into the ford plug issues mentioned above. that's pretty disappointing if true. if the issues keep up maybe ill be buying another set but let's hope she keeps running smoothly.