I'm asking here cause the Ranger forum is worthless. (Not one reply at the time of this post)

I've been fighting a missing problem thinking it was sensors or injectors. After realizing a few new symptoms i'm not so sure.

1) When cold if i start off in first and accelerate somewhat quickly to a high rpm and then let it coast and push the clutch in it will die. When i try to restart it, it sounds like it has no compression. After a few (30+) seconds it will start to pick up and eventually run again, though not on all cylinders.

2)At any temp if i get above ~3000rpm when i shift it will start missing. It is rare for it to not do this.

I'm really confounded by #1, and i'm sure its what causes #2. I've got about 218xxx miles on it, and i'm not sure the timing belt has ever been replaced.

Could the belt be doing something funny when slowed down after high rpms? Why does the truck sound like it loses compression, but then after several seconds of cranking it will start to fire again (usually one cylinder at a time)?

 

It does sound like your timing belt may have slipped. If the cam timing retards from the crank, it'll leave the intake valve open during the compression stroke which gives the effect of lost compression. The miss at ~3k rpm could also be explained by this as if the intake valve is open while the piston is moving up, you're blowing air/fuel back out of the cylinder. If you're ignition is a DIS, your timing may be crank based and firing on time but too little air/fuel to fire causing a misfire. Misfire can cause the O2 sensor to read lean and dump in more fuel for fuel trim. If your ignition is camshaft based, your ignition timing will be retarded by quite a few degrees as well. In short.. a lot of crazy things happen.

I had a timing belt jump on my Civic once. If I let it down to idle it'd die and would be a real bugger to restart. Hardly any power and acted similar to what you're describing.

Best of luck. Timing belts should be changed by 100k mile intervals as a general rule of thumb. I usually change them at 80k. Cheap insurance.

 

If it's not too bad to take off you can check the cam timing reasonably easy. With the engine at TDC Cyl #1, the cam gear on top should have a triangle mark on it that lines up with a triangular mark on the front of the head at about the 4 or 5 o'clock position. If those marks are off I think you found your culprit.

 

I think ill go take a look now...

Stay tuned...

 

EDIT: Found the bugger.... changed picture...



Whats the next idea?

I guess i wouldnt know if it was a single tooth off, but would that cause my problems?

 

Correct. It's my 2000 Ranger. Two coils running eight plugs (for a 4 clyinder...? )

It does seem to have less power than i would have expected, but i'm reminding myself its a 4 cylinder pickup, not my diesel...maybe it is lacking power, but it gets about 21-23mpg, which i take to be the good side of normal.

 

Results from compression test, engine warm, each reading done twice:

Cyl 1- 190 psi
Cyl 2- 185 psi
Cyl 3- 195 psi
Cyl 4- 190 psi


Chiltons says highest must be within 15 psi of lowest, 100 psi minimum.... no spec stated....

 

hrmm...

Maybe you've got a plugged catalytic converter causing exhaust restriction?

 

i guess fuel filter or pump

 

does it start well first time in the mornin? almost sounds like fuel related to me weather its a regulator or pump ?

 

It's possible. The cat leaks and i have a manifold leak.

The filter is 3000 miles old. I suppose its possible, but it just doesnt seem like it.

Starts great in the morning, and when warm. I was thinking it was fuel related at first, though i was leaning towards a hanging injector. But that doesnt explain why it loses compression when i rev it up and let it go back to idle...

I'll try to get a video of it today...

 

Hook a fuel gauge up at the rail and see what your pressure is and what it is supposed to be .... Maybe 35 to 65 psi at the rail? Just an example anything lower than recomcomend try changeing the fuel pump.... Just my 2cents lol

 

last time i checked it i got 62 KOEO and 65 psi KOER.... I think that was at the top end of the specs....


The (lack of) compression is whats bugging me... I've got a new timing belt but i have to wait til my boss lets me use the shop to change it...

 

just swap a 6.9 into it and call it done

 

Riiiight...... That would crush the entire front suspension...

I did see a couple vids of a ranger with a 4bt in it which got me thinking...