Does your truck have an IGNITION CONTROL MODULE? I have received lots of conflicting information. Some say my truck (1997, 2.3 liter, base model: no power steering, no A/C) came equipped with an Ignition Control Module while others say that (starting in '97) the Engine Control Module incorporated the functions of tge ignition control module. Every parts supplier I have looked into (Advance Auto Parts, Parts Geek, Rock Auto, Amazon, NAPA, Auto Zone, O'Reilly, Summit Racing) sells a seperate Ignition Control Module that is "guaranteed" to fit my truck but I cannot find any information about where that module is located (I CAN find descriptions and diagrams and photos about '94 and '95 and '98 and others). So, if anybody here has replaced the Ignition Control Module on their '97, base model, 2.3 liter truck, please post a reply with a description of tge module location and a photo, if possible. Thanks in advance!

 

1989 to 1994 Ranger 2.3l Lima engines used a separate spark module called the ICM(ignition control module), and also used the 60-wire EEC-IV computer

In 1995 ALL Rangers got the new 104-wire EEC-V computer, which had an internal spark module, so no ICM needed on the 2.3l, or 3.0l or 4.0l
2.3l also got a new Crank Sensor design in 1995 so 1989-1994 2.3l engines are not compatible with 1995-1997 2.3ls, and visa versa, just FYI

1988 and earlier 2.3l used a distributor instead of ICM

2.3l Coil packs were the same 1989 to 1997

Your 1997 2.3l Lima Ranger for sure does not have an ICM, 100%

If you are having a spark issue or think you are
You can run the engine on just one coil pack to see if all 4 spark plugs on that coil pack are working
Warm up engine if possible
Turn it off
Unplug the 3 wire connector on one coil pack
Start engine
Should idle smoothly, if there is a steady misfire then one spark plug or wire on the working coil pack is bad

Shut off engine and switch working coil packs, plug back in the one that was unplugged and unplugged the other one
Restart engine
Same test

The 2.3l Lima engine was used since 1976 as a 4 spark plug engine, so can run just fine on 4 spark plugs
In 1989 it went distributorless so at that time Dual Spark plugs were easier to operate, dual spark plugs add extra power, so Ford added Dual Spark plugs
BOTH spark plugs fire at the same time, thats what gives the added power, there is NO ALTERNATING, common myth
So your engine should run just fine with either coil pack unplugged, just have a bit less power
Good test to do once a year to see if all 8 spark plugs are working, because with Dual spark plugs you won't know if 1 spark plug fails, power loss is hard to detect

 

Thanks for the info. The problems that started my investigation were 1) rough idle until engine fully warmed up (once warm, seems to be ok) and 2) significant drop in mileage (from about 28 down to under 20). It has been such a fabulous little hauler that I have mostly ignored and neglected it but these issues caused me to pay a bit more attention. I have been religious about changing the oil every 3,000 miles. It has 202,000 miles and I have never changed the timing belt and had not changed the serpentine belt since about the 75,000 mile mark. It was also running on the original antifreeze/coolant. I installed new belts and new tensioners along with new thermostat and hoses, new coil packs (they're cheap) as well as new plugs and wires and a new MAF sensor and air filter. It has an appointment on Thursday to have brake system flushed and filled since that, too, has never been done. I also bought a new ICM that was 'guaranteed' to fit my vehicle but once I started tearing into it, I could not locate it anywhere in the engine bay - that is when I started looking for more info: every part seller says this is a part that I need but several other sources say just what you said: this vehicle does not use a stand-alone ICM. I wonder why the parts suppliers don't know that.

 

They KNOW, they just want to sell parts, many don't bring/send them back for a refund, so....................and some electrical parts, like an ICM, have a NO REFUND policy, exchange only

O2 sensors are the ONLY sensors that wear out, 100k miles or 12 years which ever comes first
They use a chemical to detect Oxygen in the exhaust and it simply gets used up
That WILL cause a drop in MPG and won't set codes until it dies completely

ECT(engine coolant temp) sensor, its a 5volt sensor ONLY used by the computer, no relation to dash board temp SENDER(12volt)
ECT sets Choke also air/fuel mix in colder engine temps, so can cause richer running

1997 is the last year for Rangers to run an FPR(fuel pressure regulator) on the engine end of the fuel system
FPR looks like a small can, has a fuel line(return) and a vacuum hose attached
Check that vacuum hose for gasoline, not uncommon for FPR to leak a bit and extra fuel gets SUCKED into the engine, MPG drops low

 

Either you are a true professional or the most knowledgable amateur around. You are telling me stuff that I have never run across in all the things I have read about this truck. I checked the FPR and don't see any evidence of a fuel leak but, if the other things I have done don't get me back to where I was mileage-wise, I now know something that I didn't know before so,at least, I will have a jumping-off point. I hope you don't decide to leave this site so that I can know who to turn to if I run into any other issues.