4.0 OHV no power

[mosher41]

This thing is killing me:

New (motorcraft) plugs, new fuel filter, cleaned MAF, all compressions good, all spark good, plugs look lean, pressureizes cooling system very quickly, idles fine at 1000/1100. just no power at all... seems to rev up to about 2000 and then flattens out bad....motor seems to be hot but temp guage fine.

NO POWER and sounds flat when rev'd

 

[Nhaz]

The idle is rather high.

It should be idling at about 650-750. I would start looking for a vacuum leak.

My first guess is a disconnected vacuum line. Check the vacuum tree on the back of the intake for a missing/cracked cap on the free line on the tree. after that check the brake booster line at the elbow.

 

[mosher41]

vacuum line all seem good, no codes at all, and it does idle arounf 850

 

[Big Jim M]

If it isn't missing and you are able to open the throttle plate FULLY.. then we must look to the exhaust to see if all the exhaust can exit the pipes.. Is the muffler or the cat partially stopped up?
Big JIm

 

[rockwerks]

This thing is killing me:

New (motorcraft) plugs, new fuel filter, cleaned MAF, all compressions good, all spark good, plugs look lean, pressureizes cooling system very quickly, idles fine at 1000/1100. just no power at all... seems to rev up to about 2000 and then flattens out bad....motor seems to be hot but temp guage fine.

NO POWER and sounds flat when rev'd

Go pick up a 30.00 ford code scanner from autozone, chekcer etc and see what it tells ya. it might be anything from clogged exhaust, or faulty fuel pump to bad motor internals

 

[Nhaz]

When checking the vacuum system don't forget to use the old tried and true method of the propane tank and wave it around all the vacuum lines.

Any propane will get sucked in via a leak and the engine will rev up in response. almost anything that burns and is in a aerosol will do this. you can also use the reverse and use something that doesn't burn and the engine will rev down instead.

 

[redstangs9308gt]

I spent alot of time chasing down a leak. My upper & lower intake gaskets was shrunk, hardned, cracked and JUNK! Replaced upper plenium gaskets, upper intake, lower intake gaskets and problem solved.

 

[mosher41]

it has exhaust coming out...rather steamy for a bit.. but then it clears, as it has done since i have bought it. the exhaust is quite hot to the feel coming out.

how do i check it for being partialy blocked with out cutting it apart...i do live in upstate ny...and everything under the truck is effected by salt.

It acts lean as hell, the motor feels and acts HOT...but temp reads right in the middle of normal.

i idled it for a bit in the garage without the radiator cap.....was doing fine, temp on the gauge right in the middle...and then an eruption from the radiator (new themostat) blew anti freeze 6 inches out of the filler and i'll bet 2 quarts hit the floor.

Again no codes, starts good, idles good....when asked for power NO WAY

 

[mosher41]

I am going after intake tomorrow morning

 

[289-tiger-]

Why would I be looking at the MAF right now?

Good luck

 

[98 ranger xlt]

Check your oil, the way it spewed water out of the radiator suspects that you have a blown head gasket. or pull your thermostat out and make sure the spring side goes in the motor.

 

[mosher41]

PLUGGED CATS......still a little concerned with the water pressure... BUT i have all of the power back,


no water in the oil yet, it acts like the beginings of a head gasket or tiny crack.

This has been by far the WORST vehicle I have ever owned. It hasnt run 2 weeks straight yet with out some kind of issue.

 

[arin.brinkley]

This thing is killing me:

New (motorcraft) plugs, new fuel filter, cleaned MAF, all compressions good, all spark good, plugs look lean, pressureizes cooling system very quickly, idles fine at 1000/1100. just no power at all... seems to rev up to about 2000 and then flattens out bad....motor seems to be hot but temp guage fine.

NO POWER and sounds flat when rev'd

mine is doing the same thing

Sent from my SM-G920R4 using Tapatalk

 

[AdirondackRanger]

i idled it for a bit in the garage without the radiator cap.....was doing fine, temp on the gauge right in the middle...and then an eruption from the radiator (new themostat) blew anti freeze 6 inches out of the filler and i'll bet 2 quarts hit the floor.

Again no codes, starts good, idles good....when asked for power NO WAY

Bad head gasket? Vapor lock in the cooling system? Bad water pump?