1992 2.3 missing while under load

[bottlerocket]

Just got this truck about a month ago and just noticed a slight miss today. Only happens while cruising, typically in 3rd or 4th gear. It will happen while accelerating or cruising at a set speed. But when I go WOT the miss goes away which is leading me to believe its a sensor. Went to Oreilly to have the codes pulled. There were no KOEO codes and the guy wasn't the brightest, couldn't figure out how to work the reader and just shut it off halfway thru the KOER test. It retrieved codes and I think I saw "1 of 2" on there so I never got to actually see the result. He just hit the power button and said "welp, looks good..." yea cool.

Anyway, there is also some popping from the exhaust when I downshift while slowing, not sure if it could be related. I'm thinking O2 sensor but not 100% on my diagnosis. Any thoughts?

 

[RonD]

Pull the spark plugs and see what they tell you.
Could just be one plug going bad.

Doesn't sound like a computer issue, so not a sensor issue

O2 is not a specific sensor, so wouldn't cause a miss, it just tells computer if exhaust is lean or rich in general, so could cause pinging(lean) or bogging(rich), a miss is a specific kind of issue, spark plug or injector, or cylinder(i.e. valves or compression)

Backfiring could be a timing issue or rich issue, how has the mileage been?

 

[bottlerocket]

Averaging 21mpg mostly around town to and from work.

 

[bottlerocket]

Update: I was mistaken at the initial condition. The miss/bucking/hesitation still happens at WOT

 

[RonD]

I would test the coil packs, it is easy and best of all FREE

Google: autozone test ford coil packs 2.3

You need an OHM meter but they are cheap and good for lots of other things

Each coil pack has 2 coils inside and a 3 wire connector, center pin is for 12volts to both coils inside, side pins are for each coils ground, measure OHMs between center pin and one side pin, should be 0.3-1.0 OHMs, so very low, repeat for other side pin.

Then measure OHMs from 1 side pin to each of its spark plug holes, you should get 6,500-11,500 OHMs, so very high, repeat for other side pin.

If any reading is close to the edge of the range then I would replace that coil pack.

Then test the other coil pack in the same way.

Heat can change the OHM readings, so a coil that tests OK cold may not test OK when hot, but if your engine runs bad cold or hot then coil heat is probably not the issue.

 

[bottlerocket]

I would test the coil packs, it is easy and best of all FREE

Google: autozone test ford coil packs 2.3

You need an OHM meter but they are cheap and good for lots of other things

I've got a multimeter so I'll test them tonight. Thanks!

 

[schr9091]

i had the same problem pulled my plugs out to find out they were worn out gap was like .090 gap was so big that spark was jumping out the wires put in new plugs and runs great now ...open your hood at night see if you have spark arc then get some new plugs

 

[transmissions]

Scanner Danner has some of the best videos on youtube and could probably tell you your paint was chipped with that god damn scanner.
He's got a bunch of misfire videos and everything on his channel:
https://www.youtube.com/user/ScannerDanner/search?query=misfire

If I were you I'd do a little trick I learned from him, put it in clear flood mode (pedal floored) (im not sure if rangers have this or not personally) and then start the engine, It should continually crank and you can listen for misfires.

Also to test for gaskets you could just have the engine running and spray the intake area with a spray bottle and see if the motor starts to bog down.

And you can pull the plug wires and if the engine doesn't bog down on a cylinder you will know that that one is the one that's misfiring.

I learned all that from his videos and those are all easy tests so have at it.

 

[seth959ci]

I had a similar problem due to incorrect wiring of spark plug wires on the driver side coil

Sent from my VS840PP using Tapatalk 2

 

[JayTee]

I had the same problem. Sure the coils and leads were orig on my 1994, so I put a new pair of borg coils and leads, it was pretty reasonable for Oreilly... and I put a new set of motorcraft plugs, and it has fixed the same problem you describe.

2 things these lima dual spark engines need. New idle air control valves, new coils/leads and plugs... and clean your MAF sensor carefully. These engines are bombproof. You can put 300,000 miles on them no problem if you just change the oil and don't beat the piss out of it. One thing it doesn't have is any power. You can't pull the stink off a crap with this motor it's so weak from the factory.