96 ranger idle rough and pops at certain speeds

[Emoticon]

I have a 96 2.3L ranger. Recently is has begun popping, chugging, popping and hesitating. Sometimes at stoplights it idles normally but maybe a mile down the road at another stoplight it will idle so rough it sounds like it's about to die. It will idle so rough stall out on rare occasions as well. Now that it's getting cold I think the issue might get worse as to make the truck undrivable. I've noticed between 35 to 40 and 55 to 60 and 65 to 70 what will happen is if you try to give it a little gas it just slowly decelerates and will go POP! POP! POP! as long as you hold the pedal down with just a little pressure, however if you floor it it will hesitate about one second and take off like normal and get past the speed threshold where it likes to chug and pop from there it will run normally until it reaches the next speed threshold and it will do the same thing again. The popping noises seem to be coming from the passenger side of the truck. I'm thinking possibly an exhaust manifold leak due to the fact that it sounds like it's coming from one side?

Truck has 180K with a new timing belt and new EGR, also new air filter. Anyone have any other ideas on what to check? It's showing no check engine light or codes.

Thanks!

 

[RangerSVT]

Even though the CEL is not lit, doesn't mean it doesn't have codes stored in memory (these are known as soft codes). You might have multiple issues, but the idle issue sounds like your IAC could be dirty/clogged. The running issue could be timing/ignition related. Has it done this since the timing belt swap? When was the tuneup done last?

SVT

 

[Emoticon]

Even though the CEL is not lit, doesn't mean it doesn't have codes stored in memory (these are known as soft codes). You might have multiple issues, but the idle issue sounds like your IAC could be dirty/clogged. The running issue could be timing/ignition related. Has it done this since the timing belt swap? When was the tuneup done last?

SVT

Thanks for the response, when I plug my reader into the engine computer I come up with nothing. The truck has new plug wires also and new spark plugs. The issue is unrelated to the timing belt I've confirmed it's still on the marks myself. I'll take a look at the IAC when I get some time to work on it, however I noticed today now that its getting colder I drove around with my windows rolled up and the fan running and noticed that at stop lights I was getting a significant but not overpowering exhaust smell in the cab so I'm betting there's a leak somewhere that might be at fault. Previously, I was driving around with the windows open because the truck doesn't have AC so I never smelled it until now.

Thanks for the advice!