98 Ford ranger 2.5L w/ No power and bad mpg

[chewy012]

Ill take a look at the spark plugs and get back to you. Im thinking its valves because when the timing belt broke i was foing about 40mph and the pistons could havr bent a valve or something.

Yeah that's what happen't in my 'yota...

Except it was the timing chain and it fell off the cam sprocket... On 8k mile engine.... Anyway

I'd bet that's your deal though

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[Captain Ledd]

The Lima series engine shouldn't be an interference engine. Of course, that doesn't mean it isn't valve related. There are 2 gears you need to align correctly for timing, the top of course, is the cam, but the other one, for the oil pump needs alligned as well, and they have different marks. There is a triangle and a diamond, I forget which one is where, but they need to match their symbols. For some stupid reason, Ford put the Cam position sensor on the lower oil pump gear, and not the camshaft. So this is quite critical. The gears are technically interchangeable, and have both marks on them.

I mismatched my oil pump gear, not knowing through the grime and rust they were actually different marks. Only realizing it a few thousand miles later, and a progressively worse running engine did I figure it out. the shaking and kicking got so bad that a heavy acceleration on the highway made the engine nearly escape from under the hood. And now it runs better and smooth(er), but is still kinda grumbly, and has much less power than it did before.

 

[RangerDanger1998]

Im gonna be doing a compression test tomorrow and ill let yall know the outcome of it. Would low compression be timing and or valves are burnt?

 

[Captain Ledd]

Im gonna be doing a compression test tomorrow and ill let yall know the outcome of it. Would low compression be timing and or valves are burnt?

Either that or ring/cylinder wall damage. Those kind of go hand in hand though. The fix will be at the least pulling the head, if your lucky that'll be as far as you need to go.

Let us know what you get.

 

[RonD]

Compression test needs to be done with 1 spark plug removed from each cylinder first.
That will give good crank speed.
test all 4 cylinders and get at least 5 "hits" of compression stroke, you will hear it, on each cylinder.
write it down.

2.5l at sea level to 2,000ft elevation should have about 165psi dry compression average

Then get a straw and a bottle of motor oil
Put about 1/2 a straw of oil in a cylinder and retest compression.
(put straw 1/2 way down into the oil, put finger over the end and lift it out, put end in spark plug hole and remove finger)

This is a "wet" test, compression number will go up, write it down.
If a cylinders numbers were lower than the rest on dry test and jump up to match the dry test numbers then that cylinder has ring problem.
If number stays lower then it is a valve issue

 

[RangerDanger1998]

Could a faulty IAC cause the rough idle and loss of power. (I had a bank too lean code prior and cleared it)