I am having problems with my 96 Ranger that the mechanicsare having an issue fixing.
When I drive in 1st, 2nd, or 3rd and let the engine rev uphigher than normal sometimes the engine seems to cut out repeatedly. It goes away when I let off the gas and whenthe problem occurs it never shuts off the engine completely.I don't have a tachometer so I can figure outwhat RPM I am at, but you can tell by the engine noise that it is getting high.
I sent the truck initially to the mechanic and they noticedignition sparks along the ignition wires. So I had the spark plugs, wires, and ignition coil replaced.The issue went away for about a week and thencame back slowly.
When the issue happens I don't see any of the gauges goinglow. After the first fix, I started tonotice that the check engine light would flicker on each time it was cuttingout.
If you drive normal and shift at low to normal RPMs theproblem doesn't usually show up. Itnever happens on the highway in 4th or 5th gear.
This truck is a 4 cylinder and has ~200K miles on it. I want to keep it and I am desperate to findthe problem with it.If anyone has hadan issue like this please let me know.
I am possibly leaning towards a fuel related problem.
Thanks.
Joe

 

computer has a REV limiter if trans is in neutral or clutch pedal is in, you didn't mention if you have an auto or manual trans?

REV limiter is also speed based, does speedometer work?

I doubt it would be fuel related because that would be more noticeable in 4th/5th at highway speeds, i.e. higher fuel demand/flow is needed

Flashing CEL means damaging misfires are occurring, so back off when that happens, see if you can get the codes.

In '96 the ICM(ignition control module) is in the computer so not serviceable.
So coil packs are only thing you can try.
A Coil pack could be misfiring under load, can't really test for this because coil would probably test OK when not under load, i.e. engine runs fine at low RPMs.

Best bet would be to get one coil pack from wrecking yard(Ford V8s used same coil packs as 2.3l/2.5l) and swap out one of yours then test if problem is still there.
If so swap the removed coil with the other original coil.


CPS(cam position sensor) can also cause issues but I would expect full time CEL

TPS(throttle position sensor) could cause limited RPM and lean fuel mix, these can be tested with volt meter.
3 wires
Upper wire will have 5 volts with key on, engine off
Center wire is what computer reads to tell where your foot is on the gas pedal
Key on engine off, with throttle closed this center wire should have .6 to .9volts
As you slowly open throttle this voltage will slowly go up, at wide open throttle(WOT) it should be above 4.5volts
Open and close throttle a few times while watching voltage, under 1 volt and above 4.5volts each time and no dropping or jumping up of voltage in between.
If voltage is only going up to 3volts at WOT then RPMs would be limited and air:fuel mix would be very lean causing flashing CEL.


A good investment these days is a Bluetooth OBD2 reader, $20-$45.
These plug into ANY vehicle made or sold in the US/Canada after 1994, so not Ford specific, you connect to them with a Smartphone, iOS or Android, or laptop with Bluetooth, and you can view real time engine data or get codes.
You could view TPS voltage or any other sensor data while parked or driving.

 

Truck is a manual. Speedometer works. I have a code reader and nothing is showing up. The mechanic stated they had the code scanner on the truck while they were driving and saw no issues.


Mechanic told me they warranty replaced the coil they replaced the first time and they also replaced the second coil.


They suggested that the issue is happening at ~2500 and below. I asked them to look at that more carefully when they drive it again to see if it is consistent.


They were avoiding the CPS since it requires a bit more tear down to get to.


Do you have a particular Bluetooth OBD2 reader that you would recommend?

Thanks
Joe