trying to help diagnose long distance

[black_demon69]

ok 06 ranger 4.0l sohc w/ 75 k miles won't start.

it will crank and try to catch. it has spark and 65psi fuel pressure. spark plugs keep getting fouled..

i'm thinking either cps, ckp, or timing chains

what do you think? sorry i don't have more information as the truck is 1800 miles from me.. also it was started to warm up when it was -30 out and when they returned to the truck it had stalled and has not run since....

 

[Andy D]

Eeesh. Stories like this make me glad I blundered onto the the 4.0 OHV . I only have heard bad things about the OHC 4.0.. Only I have heard is that the rear stuff can be worked on through the fender well some how..OTOH, 75 k miles is kinda short. of the problem, which is 100k +. Was the engine getting noisy? The OHC failure isn't sudden, they get noisier before total.
OR
The Hail Mary may be a new set of plugs. What if this happened? The truck started at -30 and idled for a while but never warmed up due to cold and flooded as a result? Gassed plugs dont do well. Pull the plugs, either get fresh or bake them or use a torch on them.

 

[black_demon69]

Eeesh. Stories like this make me glad I blundered onto the the 4.0 OHV . I only have heard bad things about the OHC 4.0.. Only I have heard is that the rear stuff can be worked on through the fender well some how..OTOH, 75 k miles is kinda short. of the problem, which is 100k +. Was the engine getting noisy? The OHC failure isn't sudden, they get noisier before total.
OR
The Hail Mary may be a new set of plugs. What if this happened? The truck started at -30 and idled for a while but never warmed up due to cold and flooded as a result? Gassed plugs dont do well. Pull the plugs, either get fresh or bake them or use a torch on them.

they already put fresh plugs into it
and it has been put into a warmed garage ever since it died which is about 70 degrees so thats about 100 degree differential and rules out extreme cold...

and yes i know that 75 k is not alot and that the problem usually hits over time.. but my thinking is that maybe one of the chain tensioners failed in part as a result of the cold at least thats my theory.. the only other thing i can think of is ckp or cmp sensors..

 

[Diesel Mechanic]

Just a Long shot, check the throttle valve. A broken throttle/idle air control valve could cause this level of over fueling.


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[55trucker]

It's not easy to try and *arm-chair* diagnose a problem almost 2000 miles from you..

the SOHC is a non-interference engine, if for some reason either of the tensioners has failed ( I was under the impression that there was a TSB for the left side chain tensioner assembly) then you've got a mechanical problem.

Assuming no mech failures, I would take a look at the MAF sensor. A failed MAF will cause a no-start condition, and it won't cut fuel or spark.

 

[JerryC]

Have they tried to pull codes on it?
Out of curiosity what oil was in it when they tried to start it at -30?

 

[black_demon69]

Have they tried to pull codes on it?
Out of curiosity what oil was in it when they tried to start it at -30?

no codes (that i know of)
will have to ask about oil

 

[naford]

I think you should try running the test for the throttle position sensor. Years ago I had a problem where my 4.0 would only start on wide open throttle until it warmed a little then it was ok. I took it to a dealer to get it fixed. I was out of state at the time.