B2300 (2.3 duratech) bucking at low RPM under load

[simple_gifts]

Vehicle in signature; new plugs in the last 20K miles or so; TB looks clean.

Runs great; pulls strong to 4K+; issue occurs when a bit below 2K RPM the throttle is opened 3/4 or so. (

It seems like the ignition is cut off for a few milliseconds and then comes back on; vehicle bucks. (makes it super bad since it is a manual)

No CEL.

Any chance the coil would malfunction just under these conditions? Any other things to check? Wires?
Can fuel injectors cut out?

At this point I might just randomly replace ignition parts.

Any insight is appreciated;

-Thomas.

 

[mk378]

If it has spark plug wires, replace them-- you can't tell their condition by looking. Inspect the coil(s) for cracking or burning.

 

[Nick1994]

I had this identical problem with my Camry. Figured since I changed the spark plugs and wires it couldn't be that.

A spark plug wire was arcing on the valve cover. New spark plug wires and it runs fantastic.

 

[CKN]

I had this same problem in a Ford Contour with the Duratec in it. Despite taking it to the best diagnostic guys around-the problem was elusive. I finally got rid of it.

 

[SwampSurvivor]

May be an ignition coil, sounds it. My Duratec engine fills the spark plug wells with oil .... that can kill a coik quick.

I don't know about Rangers but I have a bad coil on the f350 right now and it won't set a check engine light

 

[JimPghPA]

A weak spark caused by a bad coil will cause the symptoms described.

 

[simple_gifts]

Will be ordering wires and a new coil; Miller88, these 23NS duratechs are not coil on plug; they have a coil right on top of the valve cover about 3/4 the way back on the engine, probably placed there for ease of replacement lol. Needlesstosay, i am taking everyone's supplied advice.

Will update thread when status is changed to solved or fiasco.

Thanks.

 

[BigD1]

Not the same engine, but my GM 3.1 engine was doing the same thing randomly. After about six weeks, it finally set a code for MAP sensor. Put a new MAP on it, and that solved the problem. The car has OBD1, but the code was never set until it went into limp mode for the first time with the bad MAP sensor.

 

[spk2000]

My 3.0 Duratec had a coil pack go bad. 2 different shops could not identify what was wrong and why engine would buck. One shop said they had a $40,000 scanner that could identify anything. Service engine light was on but it would only tell him there was an issue with plug #3. I looked up likely problems online and coil packs were a known issue for this engine. I asked him if he thought it could be the coil pack and he said not likely since it looked ok and in dark there was no arcing. I asked how much he would charge to install one and he said around $50 if I got the part. It cost around $50 so was worth a try and sure enough it solved the problem. Was woirth the $50 to not reach back near the firewall behind the engine.

 

[Rand]

the 3.0 duratech was almost minivan-ish to work on..

but with removing wipers and cow wasnt too bad the hardest part was getting all the wires back on correctly.

 

[andyd]

SG get some boot grease for the wire swap

 

[meep]

definitely an electrical problem on the high tension side.
- weak coil
- bad plug wire
- bad plug
- bad cap/rotor if equipped

 

[simple_gifts]

This issue is resolved; got my new coil in plug wires from RA; didn't bother to install them; what I find is a 6" diameter mouse nest of black fiberglass and acorns tucked between the engine, fw, and underside of cowl; clean it out and find 1 dislodged SP wire just 'sitting in the well' on the back cylinder; tough to see, i didn't bother pulling out the spotlight until i decided to do the repair, and find the scheduled repair is no longer necessary; kinda dark back there..... lol

Mice seem to like this vehicle as they chewed thru the MAP sensor wire and detailed here

https://bobistheoilguy.com/forums/ubbthreads.php/topics/3504700/Electrical_connector_pin_remov

Thanks to all that contributed.

 

[simple_gifts]

Well, that fix did not last long; will be changing wires once the sun shines.

 

[Nick1994]

When I was having the issue with my Camry I texted a buddy of mine who is a mechanic. He asked if it set a CEL yet (it had not). He said to hold down the gas pedal and brake pedal while in gear for a couple seconds, that it should set a code then. I did that and it was really rough, ran terrible. On my 1 mile drive back home after doing that it set a CEL for a misfire! That's how I found where the wires were arcing.

 

[simple_gifts]

New Denso wires; thanks RA for sending me a package without the indicated dielectric grease.

Runs like a dream! Odd that something that would be done routinely 30 years ago, had to be dragged out of me; cars are just too good these days....

-Thomas