Truck fires, then dies. Will sort of run if I add throttle. Barely. Lots of gas burning off. Exhaust was smoking for a little while out the pipe after I stopped fooling with it.
I went back to the truck with my scanner to check codes. Nothing stored. Cleared codes just in case. Started. It runs fine. Restarted. No problem. No codes stored or pending. Grr. So the problem is intermittent.
The 01-03 trucks had Intake Manifold Runner Control (IMRC) flaps that share a common shaft and could fail closed if the plastic bushing on that shaft broke. There's a solenoid that controls the flaps, as well as a vacuum controlled actuator that moves them that can fail too. Maybe your flaps aren't working normally or are being sucked shut, and the engine isn't getting the air it should, so you're getting unburnt fuel out of the exhaust? I think there's a sensor at the rear of the intake runner closest to the firewall that monitors the flap's position. I'd expect it to throw a code, but stranger things have happened. The flaps tend to make a "ticking" noise at low rpm as they wear out, so if you've heard that recently it might be a good indicator of where to look. Also, check the vacuum lines that control the actuator as they can crack and leak or become disconnected.
If your IMRC has failed you can either get a replacement intake manifold, or some people have removed the flaps I think but it's not the easiest job. Ford eliminated the flaps completely in 04, so you could get an intake manifold for one of those trucks and never worry about the issue again, but you'd get a CEL, and it might not run perfectly without a tune.
I think the first step should be to try and get the codes scanned. It would help point in a more specific direction. The IMRC issue isn't super common, but I have read accounts of it failing and causing difficult to diagnose issues. How to check IMRC
In reply to STM317 : thanks! That's certainly possible, but I did have to swap out the intake and acuator when I bought the truck. About 10k miles ago. I used Ford parts. I suppose something could be wrong with them, or maybe carbon or something has built up but it seems odd so soon? Also, initially when I had the truck and the actuator first failed, I tried driving the truck with the flaps in either position. It drove, not super well, but it did drive. The way it was last night it wouldn't idle and would barely rev. Really felt like it was only sparking on one or two cylinders.
Thanks for the insight though!
The thing about the IMRC's is that they should close on that cold idle. Or at least that is how we saw the calibration on when doing research on that motor so long ago.
The rich part bothers me a little- there are not many reasons why it would suddenly run that rich unless the MAF sensor failed. Even an IMRC failure would still make it fuel closer to correct than that.
It's also possible that one of the two coil pairs failed in the coil pack. Those are pretty cheap to change.
In reply to alfadriver :
Could it be so rich because it just wasn't burning off the gas? So maybe it wasn't so rich just wasn't burning it and I was smelling the gas so strongly?
Ok, just reread my original post, and I realized it cut half the post away! The most interesting part of the story!
I went back to the truck with my scanner to check codes. Nothing stored. Cleared codes just in case. Started. It runs fine. Restarted. No problem. No codes stored or pending. Grr. So the problem is intermittent. Sorry guys, I don't know what happened but I hope that completes the story a bit. I'll edit the original post.
joey48442 said:In reply to alfadriver :
Could it be so rich because it just wasn't burning off the gas? So maybe it wasn't so rich just wasn't burning it and I was smelling the gas so strongly?
That would be the coil pack problem. I can't think of another failure that would make it that rich all by itself, unless you were marshaling the vehicle around your yard (start, drive for 10 seconds moving it, shut down, repeat as needed to get on the train). The other possible trigger for crappy fuel should not make it so rich that you are beyond the rich limit. Other than that, there's not much built into the system that would make it fail so rich that you could smell it.
joey48442 said:Ok, just reread my original post, and I realized it cut half the post away! The most interesting part of the story!
I went back to the truck with my scanner to check codes. Nothing stored. Cleared codes just in case. Started. It runs fine. Restarted. No problem. No codes stored or pending. Grr. So the problem is intermittent. Sorry guys, I don't know what happened but I hope that completes the story a bit. I'll edit the original post.
You may have had a pending code that you reset. Which would have also cleared the FMEM reaction. Although, I still struggle to find what would cause it to be that rich, other than an ignition failure.
Sounds like a coil issue then? My crappy reader stated "no pending codes" before I cleared anything, but I don't know if I believe it
Clean your MAF. That was a common cause of poor running for fords of that era. Plus its free so start there.
Just got home. Drove the truck, seemed ok. Check the codes again, being sure not to hit erase, and nothing active or pending. Not sure what's going on with it. I'll try cleaning the MAF and maybe a new coil pack
So the other day I cleaned the MAF. Then we left town for the weekend. Got back, I drove the truck to work yesterday and everything was fine. About 70 miles or so. But today I make it almost to work and it dies while accelerating accross an intersection. I coast to a stop, and after a couple tries I get her restarted and drive the rest of the way. It’s weird, it just shut off like I turned the key off while I was pulling accross the intersection.
My first thought with today's developments is something fluky with the fuel pump, but that doesn't really fit with the previous scenario. Is the truck charging properly? Maybe it's the "catch all" grounding issue?
In reply to STM317 : I suspected that! When I got into work I pulled and cleaned the battery terminals I’ll check voltage when I get home. I also pulled and cleaned the idle air control don’t know if that makes a difference but we will see. I’ll check fuel pressure as well, but with all the gas smell it would seem like that’s not the issue
I wonder if the coil pack could be failing? That would explain the fuel smell.
I ordered a new coil pack. The one that was on there was aftermarket already so it could already be bad...
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