4L SOHC not taking throttle

[A Blaikie]

4L SOHV not take throttle

Hi All

Thia is an odd one, 4 L SOHC will not take throttle after 3000 rpm, otherwise runs ok, Ford UK have washed there hands on this one, there dianostics is one cam has slipped its timming ? sounds a bit off to me, however it has landed on my door and as he is good customer to us I would like very much to make it run. Can anybody help

 

[jimbo74]

is the check engine light on? when my Mass Air Flow Sensor was encrusted with mud after rolling my truck, it would barely run, nad it would not run without me giving it gas, if i went full throttle, it would only go to about 2800 rpm and basically redline there.....

 

[Crankcase]

I changed the misspelled title so as not to confuse people...

 

[Nate1]

Knowing the problematic tensioner and cam guide system in the SOHC engines, I would say their diagnostic is entirely possible.

 

[A Blaikie]

4L SOHC

Can you tell me more about this cam arrangment, Ford UK have told him this is what is wrong and will cost $4000 to repair, more detail's of the fault can be supplied if needed

Alan

 

[EliteConcept]

there might be a recall for his throttle body i know my 97 had one

 

[Howard]

Just trying to think clearly on this one. How can it run normally at any rev range if the camshaft is out of sync? One would expect it not even to idle properly in this situation. I think Ford UK are just saying that they don't know and can't be bothered. I have found that none of the UK dealers have a clue when it comes to the explorer. Does it just balk when you try and go above 3k like you press the throttle but nothing happens. What is the history of the fault developing. Did it just suddenly happen or was it gradual? Need a bit more info on how it ended up in this situation.

I still find it incredible for a chain to jump a gog and it still to run at all normally.

 

[A Blaikie]

4 L SOHC throttle

Someone at last is thinking along the same lines as I, your right to say Ford UK dealers are hopeless when it comes to Explorer's, most are geared up to carring out service work, the other reason is cost I think in this case it might be a fob off. Whatever the reason its my problem now, what Ford have done so far is to make it worse, they have changed plugs and tested all sensors they say all checks out ok, you asked how it got to this ? well its a long story but Ill keep it short, he went on holiday with it to the south of France about 2500 miles round trip, he felt it was not the same as normal, loss of power when overtakeing that kind of thing, but otherwise ok, so when he returned he booked it in for a check over (as you do) that was 4 month's ago and it's never went right since there final diagnostics were the cam timming has slipped on the left hand bank, and engine will have to be removed to repair. I have test driven the vehicle and I think it is in limp home mode my self, no check engine light on and an emission test is spot on, but as soon as you hit 2800 rpm it bulks out

 

[Billy177]

a clogged cat maby also there is a thing at the top of the engine that opens at 3k for more power maby that is screwy

try a new fuel filter also an idea check the voltage at the fuel pump i have a feeling that it is weak and not supplying fuel if you have an scanner check the a/f ratio while reving the engine to 3k rpm i bet it gets real lean

 

[Howard]

A thought has occurred to me. The IAC is designed to open @ 3000k to let in more air. Maybe it is stuck closed and that is causing the problem. This would not lead to a CEL coming on or a code being logged. It would also pass any exterior voltage test. Worth a look for the sake of two bolts.

 

[Jason_25]

Howard, I think you are confusing two different items. I don't think the IAC plays any part in upper engine RPMs. The VIS (Variable induction system) Is a flap in the upper intake that opens at 3K rpm to make the engine more efficient in the upper RPM's. You should try to verify that it is working, but I would think it would throw a code if not working right.

 

[Billy177]

it is vaccum operated so i do not think that it would throw a code but i dont feel that it would cause teh engine to die at 3k rpm my bet is on fuel filter/pump

 

[Howard]

Yup I knew there was a valve that opened at 3k but there you go 'should check facts before typing'.

The good ol haynes book says that a weak coil pack could cause loss of power. Or a clogged fuel filter or weak fuel pump. EGR valve could also cause trouble as well.

 

[twomedicine]

Something simple?

Check the simple, most likely first. Sounds like the old problem of a restricted fuel filter, hopefully. Or it could be something having to do with the fuel delivery.

If that filter is old that's only a $9 USD replacement to try first, and check your air filter/

I had a chain driven cam jump before, and it ran terrible at every RPM