2.3l rough idle and feels like missing

[ncsdaonex]

So Ive had my 1997 ranger 2.3l 5 speed for 4 years and it had a litte miss now and then when I first had it and its gotten worse and worse. So recently Ive replaced different things because Ive had enough with this. I love my truck I just want it to run correctly. So first Im a 2nd year auto tech so I know how to replace parts correctly. Replaced spark plugs with motorcraft platinums, then new bosh premium wires, swapped out coil packs with ones I knew were good, checked for vacumm leaks. Still the miss is same as before. Heres what the truck does, If I rev it up and let the rpms go to idle it will miss and shake the entire truck for 30 seconds or so then its fine till I do it again. When Im driving is usually fine, it just does it when I let the rpms go back to idle or when I slow down at a light. It will also miss when I first pull out for a little till I get going and get the rpms up. I can give it little throttle or full throttle when it does this miss and makes no difference, it seems like when its wet out or hot out its worse but this isn't always the case cause its very intermittent. I read on identifix that a common problem it sticky exhaust valves? My last guesses are sticky exhaust valves, dis module, or fuel injectors. I just don't wanna waste anymore money. So please any help would be great, also this is a 2.3l with 8 spark plugs.

 

[SRich]

Do you have any other problems ie. faulty tach indications. Might be good to clean your MAF sensor.

 

[SRich]

I have some of the same problems. I have replaced plugs, wires, coil packs, ICM, Throttle position sensor.

 

[pocket-rocket]

Last time mine had a slight miss at idle I found the parts store gave me plugs that were too short so the spark wasn't all the way down in the combustion chamber. I had decided to change the plugs again a couple years later because I got tired of the miss. When I got the first plug out and saw how much longer the threads were on this new set of plugs I stopped and went back to the store to make sure it was right. Sure enough it took the longer plugs and it runs fine now.

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[97rriding]

My truck does the same thing. Did you find the problem?


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[WarHawk-AVG]

Ditto here on my 1997 2.3L XL auto trans, I did fix a little of the problem by running a quart of cheap ATX transmission fluid in a full tank of gas for a few tanks, it helped ALOT but it still occasionally missfires.

The other day when I was working on the heater and the truck was idling I could hear the injectors clicking...it was odd because they did a louder and louder and louder creshendo then went quiet again...the truck ran rougher as the injectors clicked louder then smoothed out when they quieted down (might need to check the fuel pressure, the regulator might be acting up?)

 

[XLTsplash]

You can check you fuel trim when it's acting up to see if it's fuel or spark related. You can also do a compression test to check the condition of the engine. The coil packs are controlled be the PCM in 1997 so you shouldn't have a DIS module if your Ranger is a 1997.

 

[WarHawk-AVG]

You can check you fuel trim when it's acting up to see if it's fuel or spark related. You can also do a compression test to check the condition of the engine. The coil packs are controlled be the PCM in 1997 so you shouldn't have a DIS module if your Ranger is a 1997.

It has the two spark plug packs...but I will definitely check the compression test and fuel pressure test...just have to find a shop that can do that an NOT charge me an arm and a leg