2.3L ('83-'97) 89 misfire at idle

[gatorboy]

Have an 89 2.3 and when driving down the road as long as you stal accelerating it's fine but when you are coasting in gear it jumps and sputters also skips and sputters when idling in the driveway. I have replaced the icm and plugs and wires and the main coil all with Motorcraft parts and had no effect, I also Seafoamed it in the tank and in the motor, still no improvemenet. Help would be appreciated.

 

[franklin2]

Do you have any codes? On the older trucks like this you won't get a check engine light if you have codes, so they need to be checked.

 

[gatorboy]

Well it had a 222 code, which is why I replaced the main coil and a 334 code which I removed the egr, I bought this from an old man near me and it is in good shape for an 89, there is no rust, just a little surface rust on the frame and a spot on the hood where the paint is missing. He changed the fuel pump and the starter solenoid, and I had to replace brakes, and another starter solenoid the one he put on had the contacts fell off (and it was new) other than that I've been driving it, like I said it runs good as long as you accelerate, only when you coast or when it is idling in the yard.

 

[gatorboy]

Today I cleaned the IAC and plugged and unplugged the IAC and MAP with no success, it changed the motor when I did this but still idling the same, but since they had a definite effect on the motor i figured that they are working, I also put my hands on every vacuum line and joint on the motor and found nothing, I ran jumper cables from the battery ground to the motor and body with no success. I've got a new fuel filter for it , probably put it on tomorrow. I'm just throwing money and time at it right now because I've run out of ideas (not smart enough I reckon) any help would be greatly appreciated, tomorrow I'll try to pull the codes again and see if there is anything new, but I also am working on my Cub Cadet with fel, today I replaced the drive shaft and clutch, had to build a new shaft and weld up the clutch arm where the throw out bearing had failed, but I've been trying to divide my time between the Cub and the Ranger, again any help will be greatly appreciated.

 

[franklin2]

You may need to clear the codes out, and then run it and see if any new ones pop up. Unplugging that stuff troubleshooting may have set some more codes that you would not normally get.

Does your year have a distributor or is it distributorless? If it has a distributor, you should check the timing.

 

[rusty ol ranger]

How many miles on it?

Id check compression.

 

[scotts90ranger]

Did you check the vacuum line to the MAP sensor?

Possibly check the voltage at the TPS

It's almost sounding like a crank sensor that isn't reading right at low speed... '89 is DIS for those not familiar (I know the OP is)

 

[Jazzer]

When was the last time the O2 sensor was replaced?

Bosch O2 sensor $25 online.

-Jazzer

 

[gatorboy]

I think it has around 135000, and there is not a vacuum leak at the map that I could find, I don't know when the O2 was changed, there is no distributor, I did unplug the O2 sensor and had no effect, I am looking for a replacement now. the cat was removed when I got it, I've got by-pass pipe on it. haven't tested the TPS yet going to check now.

 

[gatorboy]

Well I unplugged the O2 sensor and no response, I checked the voltage at TPS and was 5.5-6 vdc, haven't checked cam sensor yet

 

[gatorboy]

reread code and got 334 and 485, but can't find 485 listed anywhere and even though I counted several I must have miscounted the blinks. Don't know where to go from here?

 

[franklin2]

code 334 is supposed to be a knock sensor code. You can get that by not doing the goose test. I think that is a rabbit trail. I found the 485 as a cooling fan error, sounds like another rabbit trail.

From your symptoms. when accelerating you are adding extra fuel, when cruising the mixture is leaned out, it's almost like yours is leaning it out too much causing a misfire. The oxygen sensor may be lying like the other poster mentioned.

 

[scotts90ranger]

It's a simple speed density system, all it knows is engine speed and engine load (from the MAP sensor), there's some acceleration enrichment and such going on due partly from the TPS sensor (it's 3 wires, one 5V one ground and one signal, need to check between ground and signal, should be 1V at idle and I think 4V at WOT).

Have you double checked that the plug wires are on in the right order? The coil packs have two pairs of cylinders, usually they're marked and I don't remember what is where off the top of my head but the pairs on the coil are on one side or the other. The two paired cylinders are 1&4 and 2&3, you can mix those pairs up front and back just not side to side... that's honestly the most likely cause as it's easy to screw up...

 

[gatorboy]

This is all good advice and I thank y'all, I've been doing some cleaning up today, trying to get my storage building from my old house over to here where I am now but I did replace the fuel filter earlier and it made no difference. The more I drive it almost seams like it is out of time by one tooth cause sometimes it cranks funny when it's warmed up, like spin then hesitate then spin again. Tomorrow I'm going to check out the things that you mentioned and see where that leads, might replace the O2 sensor if I can find one in stock and see where that leads. Thanks a lot and I'll try to keep you posted. In the meantime I'll just keep trudging along with it, at least it runs good as long as you keep your foot on the gas,

 

[franklin2]

That uneven cranking does sound suspicious. Tooth off like you said or the wires being mixed up like the other poster said. I doubt it's a dirty fuel filter or weak fuel pump, when you are cruising part throttle you are using less fuel. Accelerating you are using more fuel, when the problem goes away.