dkmcgowan

I thought it was the Jeep 1 adapter which is circled in red in the this photo?

Click on that link in the post above, then scroll down and it shows the original eBay auction with 4-5 pictures.

I won! I paid $217.50 for an MT2500 with a bunch of adapters and cartridges, sure hope it works and actually tells me something I can fix! http://www.ebay.com/itm/No-reserve-Snap-On-MT2500-diagnostic-scanner-with-LOTS-of-accessories-/161807894384?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2047675.l2557&nma=true&si=ipdGHiIK3RdOQyXyGmdMOR%252BUOdA%253D&orig_cvip=true&rt=nc

Today I added some Marvels Mystery oil, I'm a couple weeks from an oil change, figured it would not hurt and maybe somethings not seating all the way. It's a long shot. I also adjusted the throttle body stop again. I did it on the vehicle this time, but I loosened stop almost a full turn, making gap smaller, lesa air. I got my feeler gauge, my smallest one is like paper and it's .0015. I adjusted the stop looser until I could just barely push that feeler in between butterfly and body. I thought about going another 1/8 turn looser, but left it where it was. I still have the air bleed all the way tight. I checked two other 89 Comanches I know in the area and knocked off their caps and they were the same. Cruiser, you mentioned they should not be all the way tight, seems like some were or people are putting the plugs back in after adjusting them? When I mess with it, it will increase the idle, but it takes a lot of turning before it cannot control it anymore. With small adjustments, the computer seems to take over. Anyway, with idle stop adjusted better and air bleed all the way tight, TPS re-adjusted correctly, it's still running. No stalling or anything. In drive with the AC on, it is idling close to 700 RPM pretty steady, once you cut off the AC though it goes pretty low, I would say maybe 520 RPM, and it will settle to 550-580. So not bad haven taken so much air away. Curious where others air bleed screw landed and if I should keep messing around with that? My bidding ends in about 4 hours on a MT2500 with lots of accessories, fingers crossed I win it.

So I did some work this weekend. I replaced the CTS with a BWD one I picked up from OReilly's. It was reading spot on like my MAT sensor based on ohm chart in FSM. This seemed to help a little. I also learned the O2 sensor I had originally in there from my friend was not a Bosch or an NTK, but an OEM sensor, he had an OEM one laying around he knew was good. It wasn't brand knew, but he believes never used and just been sitting on a shelf in the shop. Things run the best with the OEM sensor. I have now put in 2 brand new NTK sensors and today I decided to purchase a brand new Bosch O2 sensor and it acts like the NTK but even worse, so I returned it. Side note, the Bosch and NTK appeared to be the exact same sensor, side by side they looked identical and had the same stamp markings on them and everything. My first NTK was from Amazon and my second from RockAuto, the Bosch was from OReilly's. I will say the flucation and idle wasn't as bad with after the CTS was changed with the NTK sensor, but still better with the OEM one, and still not perfect. So I went to my friends shop to hopefully borrow a scan tool, he didn't have the jeep1 adapter, so no good there. But... He did have another 89 Comanche in the shop that was running great, same everything as mine. So I knocked out the tamper proof plug on that one to look at the air bleed and it was just like mine was originally, pretty much all the way tight, or clockwise, that's two 89 Comanches, with the tamper proof thing still in place, having their default settings all the way tight. So I also did the vacuum tests. I made some videos. The first video has the air bleed screw turned out 2.5 turns counterclockwise. This increases the idle, but not by a ton. You will notice the difference between park and drive is not that substantial anymore, less than 100 RPM, I can only assume it was the new CTS sending some different signals.. I'm getting about 17-18 Hg warmed up (brand new calibrated vaccum gauge). I think it's pretty steady, but maybe not after others watch it, it is moving. https://photos.google.com/photo/AF1QipN1C9llQqRkisnucH0VlwW0Qi3VJRSLEGQUzakh I then made a second video. This video I tightened the air bleed screw all the way in like it was originally and like it was on the other 89 Comanche. The idle was a little smoother, but still rough. There is also hardly no change between park and drive with RPM's and it's a more steady 18 Hg on vacuum gauge. https://photos.google.com/photo/AF1QipNnH2EKAg6pvGRp-VssZxWf_AZWPfXlYZJX25ft So I think I'm going to go ahead and order an MT2500 I'm been watching on eBay to get additional data. This should give me even more information. So this is some new data, any new thoughts or ideas?

I appreciate it. I will do the CTS this weekend and check vacuum and then if that still leaves me with no new information, I will pay to have the ECU shipped to try it out. I am also thinking about getting an MT2500 from eBay, that should give me lots of hints. Thanks for the offer!

I'm going to go ahead and try to get the new CTS installed anyway, then hook up a new gauge and take a video and will post it, but I think the idle is acting correctly, steady, and strong. Should I try to seafoam it or marvels mystery oil? When I replaced injectors there was build up, I cleaned the injector holes, but could something be blocked up inside intake manifold? It only has 127k, but who knows. I know some people love those things and some people say they ruin engines. I already did a can of BG44k in the gas tank. I could add a new fuel pump as well? Try another renix ECU from eBay? I'm running out of ideas, any of these sound good?

I tested it with the car cranked, crawled under there and unplugged the connector, and I saw 12V on the red wire using the ground inside the same connector. I saw nothing with the car not cranked or running. I also replaced all the relays on that side as well, I forgot that from my list.

I will add, when I crank it in the morning it idles fine for a few seconds. The idle goes up really high, comes back down, and idles good for a few seconds, then it drops and starts the rough idle. I had read the computer is on a pre-configured setting mode for the first few seconds then it starts reading the sensors. That is what made me keep thinking it was a sensor somewhere, because I know engine is capable of idling good.

Will do...

I tested the MAT sensor again this morning completely cold, ohm readings are good. It seems to run worse with the NTK o2 sensor and I assume the knock sensor change did nothing. At idle it's like a rumble and just roughness... it seems to drive fine, it's just idle. I'm not sure what else to do. I hate driving this car now, I get frustrated every time I have to stop. It's my daily driver too. Thinking about tracking down an HO later model year one, but will lose probably 2k if I try to sell it now.

This is a summary of what I have done. Cruiser tips 1-8 Cruiser tips 11-14 Removed throttle body and soaked and cleaned until it looked brand new Tapped with 1/8 NPT the MAP sensor plug on throttle body, threaded vacuum nipple New OEM MAP sensor connected with new rubber vacuum line to new vacuum nipple New OEM IAC New OEM TPS, adjusted perfect to the .17 setting, ended up at .83 based on voltage New OEM CPS Drilled upper CPS hole for better reading New cleaned 746 injectors, all new o-rings Cleaned fuel rail New fuel regulator New vacuum harness, both sets New OEM EGR Checked vacuum on EGR solenoid, no vacuum at idle New master cylinder and brake booster (booster might have been leaking) New vacuum lines to brake booster New vacuum canister, relocated, new lines to intake manifold Tested ohms on MAT sensor, in range when cold and when hot Tested fuel pressure, 28 at idle and 34 or so unplugged, pretty cheap gauge, might have been off due to that Checked vacuum at idle, was reading steady vacuum, needle not moving, getting about 23 hg, but my gauge could be off a few on the high side, but it was steady Checked air bleed screw, was almost all the way tight, been adjusting it anywhere from 1/4 turn counter clockwise to 4 turns counterclockwise, it raises and lowers idle like it should, I've got it at 3 turns out now which has it idling 850 rpm in park give or take, idle still rough Compression test on all cylinders, all in range Tightened intake and exhaust manifold bolts, some were a little loose, all tightened to torque now New knock sensor, aftermarket New NTK O2 sensor, second NTK I've tried and a 3rd Bosch one, the Bosch one caused less pulsing it seemed, but still rough idle, with the NTK my idle is rough and pulsing some, but less of an RPM change from park to drive, no idea if this is related or even what's causing it Tested CTS, seems close to in range, maybe off my a couple hundred ohms, but not sure, no temperature gauge, it's working and setting higher number when cold and lower number when warm New distributor cap, new rotor, new plug wires New NTK spark plugs, all gapped perfect New fuel filter I think that's all I've done, it's becoming exhausting. I did use to have hard start issues, at least that has been solved along the way somewhere. I might have done a few other things too that I don't remember, but I think that's the majority of it.

So tonight I replaced the Knock sensor and put another new NTK O2 sensor in the vehicle. I tried to replace the CTS, but the existing one would just not come out. It's hard to get a 3/4 wrench in there behind that motor mount and I just stripped it pretty good on two sides. I then tried with vice grips and that was a bad idea, ended up with metal shards in my finger and a worse looking nut. I will try to get a line wrench in 3/4 if I can find one, if not I have no idea how to get it out without remove a bunch of stuff like the intake and exhaust manifold so I could get to it better. It tests close to the correct ohms, but not perfect. So I then turned the air bleed back to only 1/4 turn out so it's close to what it was originally. It runs, the idle was really low, and there is like a pulsing sensation in the idle. It's similar to when I had the other NTK o2 sensor in the vehicle. It ran, the idle would go almost to the lowest line, I believe 500 rpm, and it's just a rough idle. I turned the screw all the way to 3 turns out and the idle goes up, but it's still rough. Something just isn't right. I plan to try and get the new CTS in there, but otherwise I'm out of ideas. This car is killing me, frustrated, right now I just want to sell it and start over.

So it ran a little rough this morning, cold and warm. It's better, but I know this thing is supposed to run better. I ordered a new NTK O2 sensor from RockAuto, I also went ahead and ordered a CTS and a Knock Sensor. That will be all the sensors replaced and almost all the Renix tips done. The CTS is not outputting the exact right Ohms. It is close, but when it should be around 200 ohms it's closer to 400 ohms. It is changing with temperature, but not exact. The MAT sensor appears to be right on, and you cannot get those anyway. I decided to get an aftermarket knock sensor also, only one I could find. I will replace all these 3 things and see how she does. Maybe adjust the air bleed again after all this if something changes. I sure hope I'm getting close, it's starting to wear me down.

So put on a new Accel cap with some premium napa wires. I also drilled out the CPS upper mount hole on a new oem mopar CPS and put it back on. I then spent more time adjusting the idle air bleed. I ended up this time around 2.4 turns out. I let the vehicle warm all the way up and then kept adjusting it until I felt I found a good balance. It is idling in drive now at 600 rpm and in park around 720 - 730 rpm, so I got to around 120 difference RPM drop from park to drive, not too bad. I'm hoping going from 3.5 to 2.4 turns will make it run better when cold. When cold it seemed to not run as well, my theory was too much air when cold means it cannot run as rich as it needs too and might it idle worse. I already tested CTS, it was fine. I still have something that drops the idle maybe 80 rpm when you first crank it. Doesn't matter if it's cold or warm, park or drive, when you first crank it, it idles high, then it will have something that puts a load or drops the idle 80 rpm, then it goes back up, and it does this a few times over the first 1-2 minutes it's running then it stops and runs fine. I'm not sure if that's the renix learning or something. I'm also still thinking about getting another NTK or maybe Denso O2 sensor since the NTK I got just happened to be bad, so I'm not running a bosch that everyone says doesn't work well or doesn't last.

I went to do the distributor indexing today. I set my engine at TDC and cut out the distributor cap and put it back on. It looks like mine has either already been fixed or was one of the ones that didn't have an issue with indexing.

Still running pretty well. I have it set at 3.5 turns out on idle bleed screw. When it's cold it's still a little rough. It feels like sometimes there is a small strain on the motor and idle goes down, but then goes right back up. This is only for a minute maybe, then while it's still warming up the idle is holding, but you can feel a slight stumble, but it drives fine, only at idle. Then once warm it's idling pretty awesome now, you might feel the stumble once if sitting for a few minutes. Any thoughts on what that would be? Plans for this weekend are to reindex the distributor, drill out the top whole on my new OEM CPS, and replace the fuel lines going to the tank and the one rubber piece inside the tank because I was about 3 psi low on fuel pressure, not sure if it's real or the gauge. I also still want to try another O2 sensor, I don't trust the bosch unit, might not be working smoothly, but it is working. The NTK one I got didn't work at all, so it's being returned to Amazon today, might try to pick another NTK one up locally, but searching eBay for an OEM right now with no luck. Getting close!

Just to add. I wanted to know for sure, so I put the ntk o2 sensor back, drove around block, fluctuating idle always and low idle. I pulled back to house, let cool a few minutes, put back in my other new Bosch o2 sensor, did same drive, steady idle. So the new ntk o2 sensor from amazon must be no good, that didn't help my diagnosing.

So went out tonight and just set that air bleed screw like I would set idle mixture screws on a carb. I figured knowing all the other parts were working this made sense. I hooked up vaccum gauge to manifold and tach to the coil. I played around and landed on 3.5 turns out. I was adjusting with quarter turns. If I went to 3 turns out, my vacuum and idle started to drop a little in park and drive, and the same at 3.75 turns out, so 3.5 seemed like a sweet spot. You can crank it to 4 or 4.5 turns out and get the idle to go up in park, but not much more in drive, and the vacuum doesn't go up anymore, so I stopped at 3.5. I ended up getting pretty steady vacuum. I was getting 23 hg in park and 20 hg in drive, hardly no flucuation. I was getting about 770 rpm in park and 630 rpm in drive. From my carb days more than 100 rpm difference from park to in gear meant you were not tuned perfect, so not sure how to make that better or if it applies on this type of car. So it's running pretty decent now. The only thing I noticed now was while idling, every minute or so when cold and less often it seems when warmer the idle drops by like 80 rpm and then goes back up. When this happened the vaccum didn't move much, maybe 1 hg. Engine sounds fine when it happens, just like a load is on the motor for a second or something like when you turn steeming wheel but without the steering pump whine.

When I pulled the cap off, it looked like it had never been removed before unless someone was much better at removing it than me. It was all the way to the right, clockwise. It might have been like 1/8 - 1/16 counter clockwise, I know when I put the ratchet on it, I was able to snug it some to the right, but not get much of a turn at all. So I'm 4 turns out from all the way tight. I assume this screw was originally set with air/fuel meters or something? Any idea where it normally landed to see if I'm in the right range or something? It idled much better on the way to work today.

I just went and tested o2 sensor connector. With key on, orange wire shows nothing, ground is good, 3rd wire shows 5v. I then fired it up, orange wire went to 14v. I decided to put back in the Bosch o2 sensor. I fired it up, ran great, drove around neighborhood, ran and idled great. I let it warm up to 210, still idled great. So it's idling like I want now. I will get a better test drive to work tomorrow, 5 minutes of driving is never a solid test. I feel the Bosch sensor is working better than ntk, maybe I got a bad one or damaged in shipping from amazon. I'm still 4 turns out on air bleed screw, which I know is wrong. I read 1989eliminator post again, his also started all the way screwed in clockwise, so that must be normal because that is what mine was. I think it's idling better now with other o2 sensor, might be able to go back in another turn and have it still run good, or more, we will see. I'm officially out of things to try now. Will try screwing back in the o2 sensor tomorrow and then I got nothing as to why it wants so much more air. I haven't done the distributor tip yet, about the only one, considering that for this weekend. Unless my iac was bad and I happened to get a bad nos oem one from eBay and was that unlucky, that could make it want more air. Otherwise it's dumping too much fuel and wants more air for that I would think. The cts wasn't perfect. It was about 360-380 ohms when I think it should have been closer to 200 ohms. It's working, but seems inaccurate slightly, should I try a new cts? The mat sensor was a lot closer to 200 ohms at the same time and vehicle gauge was showing like 215 degrees F

So I got in the new TPS. I installed it, adjusted it using the .17 method, and no change. I made sure to check the MAT and CTS when I got home and it was warm. The CTS showed about 360 OHMS and the MAT showed about 260 OHMS, which is pretty close to where it should be after driving home around 210 degrees with 5 minutes to sit and cool off. I tested it the other day when it was around 100 degrees give or take guessing and it showed around 1300 OHMS, so they both appear to be working. I then took off the cap to adjust the last resort idle air screw. Mine was turned all the way to the right, 100% tight, no extra air. Is that the default? I keep adjusting it and playing with it and settled on 4 turns to the left. This makes it idle much better. That seems like a HUGE adjustment unless all the way tight was wrong in the first place. So it wants more air at idle, that's for sure. This rules out a vacuum leak on the intake manifold right? What should I do next, I'm at a complete loss and feeling pretty defeated. Can I drive it with 4 turns out like that, it runs better? Thinking about putting the Bosch O2 sensor back in tonight when it cools off and seeing how that does during a drive to work, I feel like the NTK made it worse, but who knows at this point with all my changes.

I agree. I drove to work today. It's not just low idle, it's like it's surging as well. The engine is not completly smooth, there are vibrations from the surging or pulsing, not a miss, but feels rough. I feel my gas mileage is bad too, but don't have numbers on that yet and it's all in town driving. Will do tps after work today and see. I have not replaced the mat or cts, but they both seem to output correct numbers when engine was around 100 degrees give or take, seemed good or in range. I need to test cts and mat when fully warmed up, might do that after work also. I also just tightened the intake and exhaust bolts and did not replace gasket. I've gotten pretty frustrated. I sold my Wagoneer to get a more reliable fuel injected daily driver and it runs worse than my old carburetored AMC 360 did. When you adjust that last resort screw, how much do you adjust and which way do you turn it normally.

Should the idle change if I'm moving the tps while running and the voltage is changing? I fear since I can get tps to correct setting and when I move it the voltage moves, that the new tps tomorrow will make no difference.

I cleaned the last couple of electrical connectors today, no difference. I also drove it all day. I think it's pretty much running exactly the same as before. It might be idling a little better, but not really. I decided to unscrew the tps while it was idling. It should be set at output .83, I moved it, while running, all the way to .40 and up to almost 1.0, both extremes, and there was no real difference in idle at all. Does that mean tps isn't working or something else is wrong?