Low Idle in 94' Explorer

[YooperSteeze]

I have a 94' Explorer, 4.0 OHV, and its very tired with either 196k or 296k. Took it on a wheelin trip to my buddy's camp this weekend, on the trail there I developed a low, 500 rpm, and very rough idle, but as soon as I got on the throttle she cleared right up. It got slowly rougher and rougher as the weekend went on. Today I had to get some gas in BFE to make it home, and of course they were out of regular so I was forced to pay $4.69 a gallon for premium. When I went to pull out of the station, I turned the key, it started but died out instantly. Tried again and got it to stay running by revving it to 2k and I high tailed it out of there. I let the rpms drop to slow down for a corner and it instantly died out, went to neutral started again and just kept her to the wood the rest of the 45 minute journey home. Got home, cleaned the MAF sensor and gave it a bottle of seafoam and it ran, but only idles at 5-600, even after fresh gas. However it is idling a lot smoother than it did before when it was that low. The check engine light is on, has been since I got the vehicle, last time I checked the only relevant code was clogged egr. I talked to one of my buddies and he thought it might be the idle air valve but we didn't get a chance to look. So I'm asking for any help or opinions. I'm not the best with engine work/diagnosis. Thanks in advance!

 

[Explorin94]

It appears that you have some diagnosing ahead of you. Sparkplugs? Wires? Fuel pressure? Fuel filter? Ever done any of these?

 

[YooperSteeze]

Haven't done those on this. Added a few fuel filters on my ranger, been around and paid attention when my buddy has checked plugs on our race truck. Beyond that nothing else you've mentioned.

 

[daniel3507]

Start basic first. Change fuel filter, check air filter, PVC, make sure its got spark. I know you said you cleaned the MAF but I had to replace mine after cleaning. Ran better.but not great after cleaning so don't count that out 100%.

You may just want to replace the IAC rather than clean it. They are hard to really get clean

Sent from the think n' stink.

 

[YooperSteeze]

I picked up a fuel filter, tossing that in after class today. Hopefully that clears it up. Already checked the air filter/box, thats all good.

 

[YooperSteeze]

Finally got my fuel filter in, after getting blasted in the face with gas... all part of learning to get out of the way hahah. Anyway, that didn't clear up my low idle but it seems my mileage has gotten a little better. What should be next on my list to check? Cleaned MAF, checked air filter/box, changed fuel filter. Thinking of checking back pressure, my buddy thinks I might have blown my cat after running it for awhile and it getting dunked in nice cold water when I was out wheeling. It has spark, because it runs. Still daily driving it.

 

[Explorin94]

IAC motor passage could have carbon it in. Clean it with carb cleaner. Is it sluggish when you drive it? I don't know if the cat would be bad cause you sunk it in some water.

 

[YooperSteeze]

Yeah the cat thing sounds to me like some crazy theory but my buddy has seen it happen. Yeah its sluggish, it has been since I bought it though. I need to take some time and figure this out. Thanks to everyone who has helped so far.

 

[aspevacek]

Look into cleanign your IAC and look at the "Blocked " EGR port. EGR can cause all kindas of strange idle issues.

 

[YooperSteeze]

Yeah those are top of the list now, just need to find the time... Damn college. Never listen to your adviser. Mine has me taking 18 credits in my first semester.

 

[YooperSteeze]

My buddy hooked me up with an IAC off a 4.9 that he found at work, I tossed it on the other night and now she runs and idles beautifully!