Hello,
I need help from some of the Ford experts that frequent this forum. I have a '97 Ranger, XLT, extended cab, with a 2.3L four-banger (0-60 in 3.2 hours, a little longer if I have a passenger ;-), and a 5-speed transmission. It has 107 K, and up until now she has been pretty reliable. In February, after driving for an extended period, it would start hesitating at RPMs ranging from 2500-3500. My good old '86 Ranger, also a 4-banger (which I regret selling), used to experience a similar problem every couple of years, and I would change the Throttle Positioning Sensor and she was good to go. So I went and bought a TPS for this one, but due to a mission trip I took to the Philippines in February and March, I was unable to replace it until recently.
First, I thought I had the problem licked. She seemed to run a little smoother, but then, after extended driving, it started acting up again. AAARRRGGGHHH! :-(
After my initial colorful expletives (which, thankfully, I no longer use in public), I got a more sensible head about me and closely examined the symptoms as I was driving. After the truck has been running for a while (up to temperature), at engine speeds ranging from 2500-3500 RPM, in any gear (remember, this is a stick), it would hesitate for a split second, sometimes in multiple succession lasting a second or more overall. On some occasions there would be no movement of the tach needle, on other occasions the tach needle would drop down to near zero and the "Check Engine" light would flicker--it almost seems as if someone turned off the ignition (yes, I did try to jiggle the ignition switch), but I would not lose any electrical accessories when it hesitates. The tach needle should definitely not drop toward zero while driving a stick, unless there is a loss of power.
Has anyone here ever experienced something similar to this? Where should I start? Are there any common problems like this? The "computer"? This truck is not my daily driver anymore, but I am getting a new pastor at my church, who is from Georgia, and for the next several weeks he will be flying in for weekends and I would like to loan him my car (so he does not have to rent), but I will not do that until I get this truck problem fixed.
Thanks in advance to anyone who can help.

Sean
Lansing, Illinois

 

Your tach it the 'telltale'. If it drops to zero, there are no pulses coming in to make it count. But, you know the engine is turning over as you are in gear and the truck is still moving(hopefully).
You have a distributorless ignition system, I think. I bet you will find a code if you read the OBDII codes. You can check the module at most parts stores, but it sounds intermittent.
I don't think it is new enough that the computer is doing everything yet, but I have been wrong before.
I am sure Rock will come by and knock it out of the park...
tom

 

Thank you for that little tidbit of advice. Yes, I have a distributorless system. My question is, will "The Zone", Advance, etc. be able to get a code if the check engine light is off? That light only comes on for a brief second when it hesitates. Meanwhile, I'll play around with the connectors to the ignition system, maybe it is just a corroded connection (I should be so lucky).

 

Given the light show on the dashboard when the truck misbehaves, you could also be looking for an intermittent ground problem, or a loose wire. The CEL is 'powered' by the ECM(computer), and if the computer loses its 'train of thought' it will 'reboot' and run through its start-up sequence, part of which is turning on the CEL as it checks for stored codes, etc. Then it gets around to sparking and injecting and all that other stuff. So, if it loses power, such as a bad relay, it will appear to be a problem under the hood, while it actually is under the dash. I think your ECM is in the passenger kick panel. All this leads me to consider checking the ground etc for the ECM relay, which provides power for the ECM, at least I think it does.
tom

 

by all means get autozoo to read the codes if there are any to read...
but.. maybe just maybe it has the 'lack of use' syndrome. why not get it up on the highway and really give it a good run and maybe an italian tuneup or two...

 

I have an '01 with the 2.5, and the same EXACT problem - sans the engine light.

Tremendous hesitation from 2100 - 2800. Did a full tuneup; EGR okay and free from carbon; replaced the DPFE; cleaned the throttle body. Very frustrating, and on Long Island, acceleration ramps are very short. Not easy driving at times.

Yet, for no rhyme or reason, on other occasions, the motor runs just fine

 

Went to "the Zone", and no codes came up. This engine has two plugs/cyl, and two ignition coilpacks (distributorless). I tried jiggling the harness for the PCM (located on the top of the firewall, passenger's side). What is the "CEL" and "DPFE"? I wonder if I could purchase a new PCM, and if that does not solve the problem, if I could return it.
Thanks for the advice thus far.

 

Iron asks.. What is the CEL?
Quote: 'the "Check Engine" light would flicker' it is the Check Engine Light.
The DPFE thingy is a bunch of valves that control EGR using exhaust gas pressure feedback. Don't know the acronym exactly.
You can check to see if the EGR is messing with you by disconnecting it for a test run. I had a intermittent misfire one time that disconnecting the EGR fixed. Bought new EGR, and installed it. Rong. There was no change, still had the misfire. Returned to stock..
Had misfire while the engine was cold one early AM and opened the hood for a look. A light show, with arcing everywhere. (damp) New plug wires and no more miss.
Did you buy the cheap wire set??? Or was this misfire there ahead of all the parts changine?
tom

 

no codes thrown so here's another thought -
iron says the vehicle wasn't run for a while. perhaps some temperature changes have contributed to condensation in the fuel tank. throw in a bottle or 2 of drygas to eliminate any water in the gas.
then fill with fresh fuel.
and then drive it!