dumb question but here it goes anyway

[black_demon69]

will a loose belt possibly cause a miss?

 

[RonD]

Timing belt............possibly, but long shot, generally just loss of power but smooth running

Fan belt.........no

Belt of Whisky.................would depend on the number of belts and what you are aiming at

 

[Doofy]

Good One, RonD! I'd really enjoy a belt of whiskey.

 

[black_demon69]

Timing belt............possibly, but long shot, generally just loss of power but smooth running

Fan belt.........no

Belt of Whisky.................would depend on the number of belts and what you are aiming at

the reason i was asking is that i have been trying to find the cause of a misfire and have looked at all of the possible culprits ; plugs and wires, vac leaks, coil, compression, injectors, fuel pressure, ect.

so now i am grasping at straws. the reason i was asking is that just noticed my belt was stretched and slipping a little and no it has not made any noise. anyway my thinking was that alt was not putting out enough power for proper spark.

engine is 4.0l in a 94 ranger splash

 

[black_demon69]

oh and if i can't find misfire i might just need that belt of whiskey.

 

[Curious Hound]

Well, you can measure voltages and rule that out. Otherwise, I like RonD's answer. I am sure the knowledgable ones will send you in the right direction on this. Do some searching. There are many threads about "misses". Look further down the main list and find the forums about your particular engine, ie; 3.0lv6 or 2.5l.

Also, the only dumb question is the one that is never asked. You can't learn without asking.

 

[RonD]

Just turn on the head lights and put heater fan to high, if misfires increase then yes, could be alternator problem.

My 4.0l "breaks" spark plugs, not physically but they do quit working outright or intermittently.
I use regular copper plugs, cheap ones, now, because it didn't matter how expensive they were, same issue, "4.0l OHV engines eat spark plugs"
I have original 1994 coil pack, seems bullet proof
I did change spark plug wires when they were 18 years old, probably should have done it at 16 years but I am cheap
Used Motorcraft again since they lasted, and on sale from Ford dealer were cheaper than "cheap ones" at local autoparts store.

I put a can of Seafoam in the gas tank once a year now.
I started getting random misfires at idle maybe 100k miles ago(at 350k now), the Seafoam made that go away, they are the original 1994 injectors, so now I just do it once a year and do notice a smoother idle after that tank is run through.

If you are loosing coolant with no obvious leak, you could have the beginnings of a cracked head, long shot but known issue on the 4.0l OHV, it starts off as misfire that clears up as RPMs increase.

If engine is warmed up and idling, you can unplug the two wires on the IAC Valve and engine RPMs will drop to 500, or engine may even stall, either is good it means no vacuum leak.
If RPMs stay high then you do have a leak.

 

[black_demon69]

Just turn on the head lights and put heater fan to high, if misfires increase then yes, could be alternator problem.

My 4.0l "breaks" spark plugs, not physically but they do quit working outright or intermittently.
I use regular copper plugs, cheap ones, now, because it didn't matter how expensive they were, same issue, "4.0l OHV engines eat spark plugs"
I have original 1994 coil pack, seems bullet proof
I did change spark plug wires when they were 18 years old, probably should have done it at 16 years but I am cheap
Used Motorcraft again since they lasted, and on sale from Ford dealer were cheaper than "cheap ones" at local autoparts store.

I put a can of Seafoam in the gas tank once a year now.
I started getting random misfires at idle maybe 100k miles ago(at 350k now), the Seafoam made that go away, they are the original 1994 injectors, so now I just do it once a year and do notice a smoother idle after that tank is run through.

If you are loosing coolant with no obvious leak, you could have the beginnings of a cracked head, long shot but known issue on the 4.0l OHV, it starts off as misfire that clears up as RPMs increase.

If engine is warmed up and idling, you can unplug the two wires on the IAC Valve and engine RPMs will drop to 500, or engine may even stall, either is good it means no vacuum leak.
If RPMs stay high then you do have a leak.

was loosing coolant from radiator tank just replaced it with a OSC radiator from Rockauto went from 1 row to 2 row with larger tanks it took an extra gallon of antifreeze to fill it.
also put a heavy duty fan clutch on it.

pulling plug on IAC just smooths out idle but it doesn't drop or stall so i am assuming an illusive vac leak maybe i will borrow the smoke machine we have at work and see.. spark plugs are autolite iridiums and all have a nice brown coloring to them... also it seems to mis when in 4th around 40 to 45 MPH and 5th between 50 and 60 MPH.
what about ICM or CAM synchronizer possibly causing mis. i will be changing wires and might just get another set of plugs. could bad O2 sensors cause a mis on this engine?

 

[black_demon69]

was loosing coolant from radiator tank just replaced it with a OSC radiator from Rockauto went from 1 row to 2 row with larger tanks it took an extra gallon of antifreeze to fill it.
also put a heavy duty fan clutch on it.

pulling plug on IAC just smooths out idle but it doesn't drop or stall so i am assuming an illusive vac leak maybe i will borrow the smoke machine we have at work and see.. spark plugs are autolite iridiums and all have a nice brown coloring to them... also it seems to mis when in 4th around 40 to 45 MPH and 5th between 50 and 60 MPH.
what about ICM or CAM synchronizer possibly causing mis. i will be changing wires and might just get another set of plugs. could bad O2 sensors cause a mis on this engine?

just tired IAC again and yes it does drop now

 

[RonD]

Didn't think 1994 4.0l had CPS(cam sensor) except in Calif., in 1995 they all got one.
But if you do have one I would expect a Check engine light if it was out of sync with crank sensor at specific RPMs

Crank sensor sets base spark and fuel injector timing, and they usually fail outright, no start, or they work fine, kind of an on/off thing.

EDIS-6 module(ICM) were fairly trouble free on these, and for specific RPM range problem it is possible but long shot.
I would suspect coil pack before ICM, if miss was only at higher RPMs

Make sure plugs are gapped wide, 0.054 was spec
Because it is a Waste Spark system 1 marginal wire can effect two cylinders