CaffeineTripp

Not that I'm so much worried about spraying TB cleaner on anything inside the engine bay, just that it's a bit hard to find any leaks on vacuum hoses and lines with it, along with carb cleaner and soapy water. So I'm under the assumption that no matter the year or engine, all Comanches had the C101 connector that was just plain ol' junk?

Seems the going assessment. Eventually I'll end up taking off the intake manifold and the exhaust manifold and rebuilding the throttle body with all new gaskets and seals, cleaning up everything on that side and getting rid of useless vacuum hoses and lines to keep it simple and straight forward. Only the things that are necessary for the engine to run and run well will I keep hooked up. Be nice to get rid of all the rats nest of vac lines/hoses. In any case, to a question that I had above, this C101 connector, is this also a problem on the '86s, or did Jeep for some reason get it right for the first two years of production and then get lazy thereafter? As to checking for vacuum leaks, besides using carb cleaner, soapy water, propane, or something else like that, I've heard that if you use a fog machine that can work as well, but then there's the risk of harming an internal sensors; MAP, O2, IAT. It's something that I've looked into purchasing so I can have the capability to find every single leak that the 2.5 has rather than going through all the hoses with carb cleaner in hopes that I can hear/see anything going on with the truck as the engine's loud as hell.

Checked out the sensors today before work. The MAP sensor is reading at A-C: 5.02, B-C: 5.0. A-C: 1.479 Ohms constant. The TPS, which I believe to be on the backside of the TB closest to the firewall: A-C: 4.97, B-C: 5.02. All of the voltage readings were taken at KOEO. The front sensor, which I thought housed the IAC valve, apparently isn't much of a valve whatsoever, more or less filled with gears, a stator much like that of the , and not nearly as much of a pain to disassemble as the TPS is on the back of the throttle body. There is also a sensor, what I believe to be a sensor, at the back of the head on the driver's side. Can't for the life of me remember what color wire that was leading to it was, was unplugged. Coolant temperature of some sort? Driver's side left, at the very rear. Also, possibly fixed a massive vacuum leak near the throttle body itself; an L shaped vacuum hose which connected directly to the intake manifold and a small, black vacuum line. Needed to be removed to access the TPS. As of now, she runs brilliantly, though it's still a bit of a trouble since I didn't really do anything.

I've done that part alway when I was going through cleaning many of the grounds I could find. Got the main battery ground cleaned on the block, head to firewall ground, and a few others. The ground strap is still in quite goos condition with no fraying.

I'll start off with the problem; the Jeep won't idle at all. Stalls. Takes a bit to start and will only start when throttle is held down. Throttle must be held down to keep the Jeep idling. Seems to have a miss until you hit ~1800 RPM. Smooth from 1800 RPM +. Cap, rotor, plugs, wires are within a year old, checked gap on plugs and it's fine. Checked for some vacuum leaks at obvious points, but a bit hard to do without a fogger machine. I've searched and came across a few options; clean the IAC, check TPS voltage on positive and sending, test MAP voltage, solder C101 connector (if it is a problem for the 1986 as well as the 1987 2.5s). Problem is, most of everything I've found is for a 1987 and above engine, not sure how much readings and connection points differ between the '86 and '87+ model years. What I've found for the sensor readings is this: MAP: 4.5-5.0 volts with KOEO TPS: ~4.82 V Positive, 17% for Output to ECU Fuel Pressure: 9-13 lbs (though I've also seen 6-9 for TBI equipped)

Manual trans. So, no very worried about any of them of course, just wondering what they all went to considering I don't have the correct manual for the vehicle. Got the '88 wiring manual in PDF. Thanks for the info!

Passenger's side connector Passenger's side connectors Driver's side connector

Besides the poor Jeep idling horribly, missing at low RPMs, and having some vacuum leak somewhere, I've got some questions about some random connectors and what they should have connected to. Also, I assume that the wiring harness for the 2.5 would be for the 4.0. I've got a random connector on the driver's side of Purple/White White/Black And on the passenger's side Connector 1 Red Yellow Black Connector 2 Red Connector 3 Orange As for the idle issue, I believe it to be ignition/sensor related as it only misses, and has a hard time starting and idling. From 1,500+ RPM she runs just fine, below that not so great. I believe that I'm going to take the TB off, give everything a good cleaning, especially the Idle Speed Control sensor as it appears that's a big problem. The vacuum leak will require replacing all of the vacuum hoses. Is there a kit? or do I have to measure the diameter of each hose along with its length to figure out all the vacuum lines. The brake booster is rusted below the master cylinder, however, I've sprayed soapy water and carb cleaner on it and there are no bubbles forming or idle changing (when the engine does idle properly). As a side note, there might be a fuel leak, though where I'm not certain. Near/on the gas tank. The engine will probably need a rebuild soon, as she's sucking down some coolant, which in all probability could affect the idle.

Way too expensive for a $100 truck. Was thinking more along the lines of my old A'Pexi SAFC knobby-style that I've already got if I'm going fuel management. I'll goof around with it and see if it's possible.

I think for the major part of it would be rebuilding the engine/swapping out for a later model longblock. Not that it needs it, but once it's done, it'll last another 150,000 easy...and have it's power back, if it had it at all. Secondly, put in a 5 speed transmission instead of the 4 speed. Minor stuff. New windshield as it's all cracked to hell, door latch for the driver's side because it doesn't close fully, and tires. That'd about do it. Body's too far gone to worry about it anymore. :dunno:

Topic as it says. What are two major things, and three minor things you would change about your Comanche? I.E. Major: Engine, aspiration, transmission, body, etc. I.E. Minor: Headlights, interior, exterior (paint, bumpers, etc.), wheels. Ready and go!

There was a guy on a forum that I was avid at, DSM1Eights.org, who changed the 4G37 engine from a distributor setup, to a coil pack set up using the Ford EDIS system, running spark timing off of the crank wheel. Turned out to work darn well, surprisingly. I think I could possibly go that route, but maybe using the stock location of the distributor and weld on a ring gear to that, or something like it, and use that for the spark timing. Can't remember exactly how he had set his up, been quite a while since I've visited his build thread. More of just a curiosity. If that doesn't seem to be the case going that route, what would be a good coil upgrade? MSD/Accel/Other?

I've been toying around with the idea, just to see if it can be done. I've got an extra coil pack from a '90 Eagle Talon 2.0 Turbo, in good condition. I haven't done much checking on any of the service manuals for either the Comanche or the Talon in terms of wiring, voltage output, and all that sort. Just curious to see if anyone has converted a 2.5 to a DIS.

Have you given changing the thermostat a shot, flushing the heater core? What's the problem that you're having? Did not have to plug that vacuum line at all. Blows 'hot-ish' heat, probably needs a flush of the heater core. Works on all the settings; panel, heat, bi level, floor, etc.

Did a little digging around the positive battery wire's loom. Found this. :doh: Gotta love previous owners and their 'fixes'. Be a while before I can get a new battery wire to supply power, so for the time being I cleaned as much of the corrosion off as I could, loaded it with solder, put heat shrink around it, and some new wire loom. Should hold for quite some time at least. I still don't know if that was the exact problem, but it sure is a big red flag.