95 Running rough

[KCwildguy]

I have been having a weird issue:

1995 XLT w/133k miles.

I have had issues lately with occassional rough idle, and it stalls. Always starts right back up. Today, it idled rough all day, and driving home, the CEL popped on for about 30 seconds, very rough running, and the engine died while driving. I got it stopped, started right up, ran smoothly all the way home. I stopped at Autozone, and they found no codes.

I have a new fuel air filter on it, and have run Seafoam and Techron through it recently. I am about to do the plugs and wires, is there anything else I need to look at? It doesn't do it all of the time, just about half. Thanks!

 

[Rudy602]

Do the plugs and wires and note the condition of the plugs as you remove them [keep them in order] they may help you diagnose your problem.

 

[gtyates]

Idle Air Control valve maybe? This valve causes the idle issue and also does not throw a CEL code normally.

 

[bantonich]

gummed up EGR valve could also cause similar symptoms.

very easy to clean

 

[KCwildguy]

Thanks! You have given me some places to start. I am just an IT guy, not a mechanic, so it sure helps having this resource.

I definitely have to figure it out, sometimes, it stalls when I let off the accelator, which is becoming dangerous.

 

[gmanpaint]

Check the codes.

Even with the cel off, there will be stored codes. If you get a code for lean banks 1 & 2, you might have a bad intake gasket. That was my case when it had the same symptoms your describing. Replaced the gasket, and all was well again.

 

[Rudy602]

gman is right - If you have the SOHC and haven't already replaced the intake gaskets, definately look at them since you probably need them anyway, might as well do the timing tensioner while you have the intake off. Check out 00M12 kit.

 

[gmanpaint]

He has a 95 OHV.

 

[KCwildguy]

The plugs and wires did not help, so I used the instructions here to clean the IAC and MAF, still no luck. If it is in a period of running rough, I can be driving along and let off the accelerator and stall the engine. Other times, it runs fine. I will look at the intake gaskets and tensioner next.

 

[Rudy602]

I didn't realize you had the OHV instead of the SOHC, so even though your intake gaskets could be bad, there's no overhead cam chain to tension. Does engine temp have any bearing on when it runs rough?

 

[KCwildguy]

I didn't realize you had the OHV instead of the SOHC, so even though your intake gaskets could be bad, there's no overhead cam chain to tension. Does engine temp have any bearing on when it runs rough?

It does seem to be worse when it is warmed up, but not every time. Some days, it runs great all day, and other days, it stalls constantly, bad enough that I have to "Two foot" so it stays running at stops. I just can't find anything bad.

 

[Rudy602]

Did you take gman's advice and check for codes? I think you may need someone more thorough than Autozone. Seems like sometimes they only get the superficial ones. Seems like not enough gas or too much air [vacuum leak]

 

[KCwildguy]

Well, I took it to Autozone, and they can't get the code reader to connect. Every time, it just errors out. Right now, I am, thinking vacuum leak or not enough gas, also. I even went so far as to check to make sure I put the new fuel filter in the right direction.

Yesterday, when I started it, it idled very rough at 3-500 RPM and tried to die. I held the throttle open at about 2k, for 2-3 minutes. I was able to let it off, and it stayed running very smoothly, but as soon as I hit the throttle again and let off, it died.

I am wondering about the IAC. I cleaned it all up, but it could be bad. I bought one at Autozone, but the plug didn't match what I had, the one they sold me (right number) had a much smaller connector.

 

[KCwildguy]

I broke down and bought the IAC, of course, I am an AB which is $40 more. I now have an idle! It is rough, at about 900 RPM. If I unplug the MAF, it smooths right out and jumps to about 1200 RPM. I am thinking bad MAF.

 

[gmanpaint]

Take it to the dealership, pay them the $75 to hook it up to their special programed machine just for your rig. They will tell you exactly what is wrong with it, and you only purchase the part you need. No throwing bad $$ at good parts this way.

I would never trust AZ code readings. They only do it to get you to buy parts from them, and there is no guarantee that it will be the correct part. Opposite is true with a dealership. Sometimes you have to bite the bullet and do what it takes to make it right.