JeepDeep

Renix 4.0 w/ 289k miles. **** poor maintenance from the looks of it.

Unplugged injectors one by one and all cause the motor to stumble except injectors 5 & 6.

I have spark and fresh plugs on all cylinders. I pulled the injectors and it looks to be three of one kind and three of another kind??? I've had it for a month or so and it's always been sluggish.

How can I test and clean these off the truck?

What's the next step if they check out?

Could this be valve related?

1991Jeep_Man

In regards to cleaning/checking the injectors, there was an article where some had used a spare connector and spliced together his own injector tester. If some of the injectors are different from others, makes me wonder if the two 'dead' injectors aren't dead or severly clogged.

Edit: Here we go! Even better, a vid! I gotta make one of these.

fishtaconc

how fresh are the plugs, how do they look rich or lean? You can pull the fuel rail, have someone turn it over watch as they spray into a pan, should be a mist not a stream. replace the orings when re installing rail. It would also be a good idea to do a compression test. How is the spark? Should be a blue snapping spark, yellow/orange spark indicates a weak spark.

JeepDeep

Awesome. Thank you. I'll give it a shot and see what happens.

JeepDeep

Just changed the plugs but I used an online spark tester with a bulb. O-rings seem rather plush. Not hard or cracked. Is it common to have leaks if you don't replace them?

Compression test is coming. Maybe I should do that first because the results could be the deciding factor as to whether or not I continue working on this motor.

1991Jeep_Man

When I replaced my injectors with the upgraded ones I bought, the lower o-rings were still attatched, and I just reused them and replaced the upper o-rings. No issues so far... and that was about 2 years ago.

JeepDeep

Ok, so I have three stock injectors and three D3800BA's. Can't find much on them.

Results from resistance testing:

Stock Injectors
17.6 Ohm
17.7 Ohm
17.2 Ohm

Unknown Injectors
17.2 Ohm
17.3 Ohm
18.3 Ohm

Anybody know if this looks good? I am planning on replacing them all but I want to confirm the problem before I spend any more money.

JeepDeep

Update:

I didn't have all the materials at hand to make the same cleaning system in the video so....We improvised.

Cherry_Key and I made it happen with a chapstick cap and a can of WD40.

Sorry pic is stubborn and won't rotate. The cap seals perfectly around the o-rings and it worked great. All injectors spray nice and even. I kinda hoped for two to fail so I could be done trying to diagnose this.

Cherry_key

Hey Jeep_Deep,

I have 6 stock injectors in unknown condition.. you can have them.

1991Jeep_Man

Have you used a multimeter to check for current at the connectors for the bad injectors?

JeepDeep

I have but I only hooked up a digital meter and it wigged out. It did the same thing with known working cylinders. I'll have to get a noid light and try that again.

Hopefully I can get these all back in tonight for a test run. I'll be cleaning and testing 6 new to me injectors tomorrow (thanks Cherry_Key) to install.

I think it's blasphemy that I have had this thing for over a month and it hasn't seen one trail.

Zack92MJ

x2 mine from a 98. Just pay the 5 bucks for shipping and you can have all six

JeepDeep

Thanks man, I appreciate the offer. I'm gonna use what I have because I know they work and once I fix what this is I'll get the ford 19lb injectors and call it a day.

cruiser54

The original injectors were prone to leaking fuel from the body itself. If it were me, I'd replace all 6 with the later style.

Price is for a set of 6 injectors:

http://www.precisionautoinjectors.co...7&categoryId=3

JeepDeep

Thanks. I'm definitely moving away from the stock injectors.