2.3 problems
 

I bought a 94 B2300 off of craigslist for $350 so i expected problems and want to fix it. It has over 300k on it and has a few problems.
first what ive replaced.
plugs, wires, maf, tps, iac, egr, oil change, air filter, clutch, slave cylinder.
The truck wasnt taken care of by the previous owner. It has an internal oil leak either at a valve or piston ring. The flywheel is missing a chunk of teeth so im unable to do a compression test. power steering leaks, brakes formed a leak and now has no pressure ( had problems with brakes since i got it).
Its always had a problem with acceleration. i shift it goes for half a second bogs way down then continues. My check engine light came on and i pulled the codes a few reoccuring ones. Maf sensor, Egr, and Igniton control. I figured the ignition code wouldnt affect it while driving so i replaced the Maf and no change. Sometimes under heavy throttle it will buck and backfire. Normal throttle it will surge forward.
It needs a full rebuild but it has to wait. i just need to pinpoint the current problem so i can get it repaired.
Im thinking it could be the crank sensor or one of the ones i havent replaced thats not all the way bad but close enough.
Id like this motor to keep going so any help is appreciated

Welcome to the forum

Just as a heads up, sensors rarely fail but are often replaced, lol
The stats are something like 90% of DIY sensor replacement was not needed, and 50% of pro mechanic sensor replacement was not needed, although I think that the later is more bill padding than ignorance

Not crank sensor, engine won't start or run if there is a crank sensor problem
Its the main timing sensor for the engine, and pretty much the ONLY sensor that can cause a no start

First thing I would do is check for a vacuum leak which is very easy to do
Warm up engine, at least 10minutes
Let it idle and unplug IAC Valve's 2 wires, IAC Valve will close
RPMs should drop to 500 or so, or engine may even stall, either is GOOD, if RPMs do not drop you have a vacuum leak, simple as that, finding it is not so simple, lol

I would get a vacuum gauge, $20, still the best diagnostic tool for gasoline engines, read here: Technical Articles: Engine testing with a Vacuum Gauge - at Greg's Engine & Machine
An engine is a self powered AIR pump and best way to test a pump is to test its pressure, vacuum gauge does that easily

Engines hesitate or bog down on acceleration with low compression, or when either fuel or spark is not as it should be, yes duh, lol.

Vacuum gauge may show possible low compression, timing belt issue, and compression test may be the way to go after that
Compression is black and white, bad or good, intermittent compression problem is very very rare
So once compression is tested it can be taken off the table, or.............if its bad you won't waste more time and MONEY on non-fixes
1994 2.3l Lima engine should run 9.4:1 compression ratio, so you would expect 160-170psi compression in each cylinder

1994 was last year 2.3l used the ICM(ignition control module)
Its on the front of the intake manifold
Most auto parts stores can test these
The ICM can run base spark timing on its own, but needs the computer(PCM) to give it a "heads up" when driver presses down on the gas pedal(TPS-throttle sensor) so it can retard the spark timing for the Richer fuel mix thats coming(vacuum advance did this in older engines)
If computer is not sending the Richer mix on acceleration you would HEAR pinging/knocking from the lean mix and retarded spark timing, and you don't mention that.

You can use a timing light to check on spark advance and retard

I intend to vacuum gauge soon and do the test.
The only thing ive replaced that i feel wasnt needed was the maf. Everything ive replaced had a reason behind it and made a difference in the way it runs.
On the way home it was acting worse. Pulling out of a gas station it starts spuddering jerking like it wants to cut off, i decided to floor it and it stops and accelerates faster than ive seen it. The backfires kept happening but only when pulling off from lights. Feeling like it has even less power than before.
I havent touched the fuel system. Could that be the problem? A clogged fuel filter?
In the state i got the truck from the owner it was clear he didnt care about the problems as long as it got him from a to b.
Id hate to see a good motor run into the ground because of poor maintenance.

Oh and any thoughts on the oil leak?

Sure fuel filter needs to be changed every 5 years, if I get a new used vehicle its one of the things I change, $10 usually

But clogged filter usually limits higher RPMS, high fuel demand

Backfires mean misfires, when a cylinder misfires, that unburned air/fuel mix is dumped into the exhaust manifold, then the next cylinder, that does fire, hot exhaust gases ignite that unburn mix and "backfire"
So backfire = misfire occurring

Have the ICM checked out, its free

And run a can of Seafoam or similar injector cleaner in the gas tank, it does actually help, I do it once a year on my 400k 4.0l and it really helps it idle smoother, the fact I notice a deference means I should do it every 6 months, lol, but I am thrifty, wife says cheap, I prefer responsible spending habits :)

Ok i will get it checked.
i ran seafoam in it when i first got it. I did the basic tune up when i first got it.
Thank you for all the help more knowledge is always appreciated.
The only reason i started replacing things is because i have no history on the poor truck, id love to keep it around to pass down.
If the icm is bad would it cause it to randomly happen? It doesnt always do it. It seems if i rev it to a high rpm before taking off it wont backfire and try to cut off on the launch. Also i replaced the spark plugs and wires when i first got it. It started ti backfire so i pulled the plugs and some were white. None of them looked like everything in the cylinders were operating correct. ive only had this truck for maybe 5 or 6 months.

Yes, ICM on the way out cause all sorts of issues, also the wiring at the ICM gets brittle and causes random issues

My problem has grown worse. When it is first started it runs fine for a minute then the check engine light comes on ( Has stayed on since we last spoke).
I pulled the codes, which is annoying because its an OBD1. So i ran a piece of wire so the check engine light would flash the codes. Honestly it seems like a jumbled mess. I ended up having to get them twice.
I got codes for the icm, maf, and egr. I just bought a new icm and the truck wont start. It will turn over but not catch.
I intend to pull the codes again in the morning and see what is staying on, but i have no way to reset the light so the codes would stay on right?
It seems like now i can take off fine when it is first started, once it reaches operating temp as soon as i let it idle down ( sitting at a light) i go to take off and i starts to violently jerk and backfire.The only way i ca get it to stop is to give it more gas until the backfire stops. As long as i keep it at a high idle it will take off fine.
At this point im at a loss and about to have to park it and focus on my other vehicle. I cant really do that since its my DD.
Any other suggestions are appreciated and i see your really the only person who responds on these forums and i really do appreciated your time. Thank you
Oh and i read somewhere on a forum that a mechanic recommended swapping the coil packs around. Could that actually have an effect on it?

Please post the 3 digit codes you got last time, each device/sensor has multiple "problem" codes that the computer can choose from, the ones it doesn't use can be as helpful as the one it does use

Look them up here: https://therangerstation.com/tech_li...gitcodes.shtml

If you turn the key off while codes are flashing it will Reset the PCM(computer), clear active codes, but will keep codes in memory, which don't turn on the CEL until they repeat

Check the wiring on the ICM connector, also ICM needs a good ground
Upper left bolt is the ground for ICM, read here: https://www.therangerstation.com/for...p/t-11509.html

I finally got a chance to test everything while the truck was running at its worst. I unplugged the IAC and it almost cut off so theres no vacuum leaks. I wiggled the wires connecting at the coil pack and the plug, i unplugged the EGR vacuum line ( no change ) I made sure the ICM connections were all the way in and wiggled it. Made sure the connections on the bay mounted solenoid were tight.
The only thing i dont know is the box mounted on the firewall with an electrical connection and a vacuum line. I unplugged the connection and no change. Im not sure if there is suppose to be a change or not.
But nothing i did worked so something is failing i just have to find it.
I am about to go out and pull the codes again but the first time i got 157, 157, 224, 332, 542, 157, 158, 224, 332, 542
Current codes are 159, 159, 115, 715, 822, 432, 733, 254, 215, 715, 823, 432, 733, 254
Im not understanding how im getting numbers that dont exist. I even recorded it so i could properly get the codes.

Yes, some oddball codes for sure

Pull out the PCM(computer) and remove top cover, its out of warranty, lol
Also check its connector for corrosion

Should look like this inside: Ford EEC-IV

You can see the 3 Blue capacitors in the picture, these can leak after 20+ years and cause all sorts of problems

Pictures here of that and the repair for it: Capacitor Repair: Ford A9L ECM « Moates Support

Cost less than $5 to repair if you have a soldering iron and some patience

I believe the ICM was the culprit. It solved my miss fires when i put a new one on and my check engine light went off.
I took it for a test drive to get it to operating temp and it did well. No type of problem while driving or at lights.
But when i pulled back into my parking spot and it idled down it was acting like it wanted to shut off.
Im not getting anymore codes. Ill just have to see how it does on my drive to work tomorrow.
It drove fine to work. Still have an issue at idle when i take off. It feels luke it has no power when i first launch then it picks up after a second.
I found my power steering leak and its the psps swicth. Its a steady drip coming out of it
Thank you for the help finding that problem.