I_s2k Posted February 5 Author Share Posted February 5 13 minutes ago, eaglescout526 said: What do the spark plugs look like? Have you replaced them? Yes, replaced the cap, rotor, plugs and wires. Old ones were down to a nub. Link to comment Share on other sites More sharing options...
eaglescout526 Posted February 5 Share Posted February 5 Ok had to make sure. Have you checked the CPS to see if it is outputting the right voltage for the ECU? Link to comment Share on other sites More sharing options...
I_s2k Posted February 5 Author Share Posted February 5 49 minutes ago, eaglescout526 said: Ok had to make sure. Have you checked the CPS to see if it is outputting the right voltage for the ECU? I have not but that’s what’s up next, I have had numerous issues with that on the 4.0s but never had issues related to misfire and poor idle, but I do want to check it anyways. Link to comment Share on other sites More sharing options...
eaglescout526 Posted February 5 Share Posted February 5 I’d check it just to be sure. After that I’d test compression. I’ve had issues where I would be driving and coolant from a bad head gasket would get into the combustion chambers and cause sputtering and for it to die a bit before catching back up. Link to comment Share on other sites More sharing options...
cruiser54 Posted February 5 Share Posted February 5 cleaned the c101 yet? Refreshed the firewall ground? Link to comment Share on other sites More sharing options...
I_s2k Posted February 5 Author Share Posted February 5 10 hours ago, eaglescout526 said: I’d check it just to be sure. After that I’d test compression. I’ve had issues where I would be driving and coolant from a bad head gasket would get into the combustion chambers and cause sputtering and for it to die a bit before catching back up. Word. 3 hours ago, cruiser54 said: cleaned the c101 yet? Refreshed the firewall ground? Yes to the firewall ground at both the firewall end and the block end. Where is c101 on these? I saw your tip for it and I can’t find a connector that looks like the c101. Unless I’m completely overlooking it which is very possible. I haven’t seen any harness’ that look to be joined so I doubt it’s been bypassed. Link to comment Share on other sites More sharing options...
eaglescout526 Posted February 5 Share Posted February 5 21 minutes ago, I_s2k said: Word. Yes to the firewall ground at both the firewall end and the block end. Where is c101 on these? I saw your tip for it and I can’t find a connector that looks like the c101. Unless I’m completely overlooking it which is very possible. I haven’t seen any harness’ that look to be joined so I doubt it’s been bypassed. You have an 86. It doesn’t have a C101 at all. 87 and 88 had this though. Link to comment Share on other sites More sharing options...
I_s2k Posted February 5 Author Share Posted February 5 9 minutes ago, eaglescout526 said: You have an 86. It doesn’t have a C101 at all. 87 and 88 had this though. Ah okay, so hat clears up a few things thanks. Link to comment Share on other sites More sharing options...
I_s2k Posted February 8 Author Share Posted February 8 Alrighty party people, so today I had the chance to once over the other side of sensors ie the cps, tps, etc and come to find out, the MAP sensor was missing the rubber hose as a whole. Can’t believe it took me this long to figure that out and I’ve looked at the MAP sensor several times😂 anyways…..went to the parts store and picked up a hose and reconnected it and now won’t stay running. I’m thinking the MAP sensor is either shot or clogged, any recommendations to brands of new ones? I know the “mopar is the best” speech but I’m not paying for an OE sensor for a motor I plan to rip out. I’d just like to get it running! On 2/5/2024 at 8:41 AM, eaglescout526 said: Link to comment Share on other sites More sharing options...
eaglescout526 Posted February 8 Share Posted February 8 There isnt any Mopar ones left. Its a GM MAP sensor so just go GM on it. That being said, if it wont stay running with the MAP now plugged back in, there is issues elsewhere. Link to comment Share on other sites More sharing options...
gogmorgo Posted February 8 Share Posted February 8 You likely need to readjust the idle after putting that line back on. That would’ve been a pretty big vacuum leak getting around the throttle. Link to comment Share on other sites More sharing options...
cruiser54 Posted February 8 Share Posted February 8 I'd pick up a new MAP sensor. Make sure there is vacuum at the fitting you're plugging the MAP's hose source on the manifold. Link to comment Share on other sites More sharing options...
I_s2k Posted February 8 Author Share Posted February 8 Thanks all for the input. 7 hours ago, gogmorgo said: You likely need to readjust the idle after putting that line back on. That would’ve been a pretty big vacuum leak getting around the throttle. You are referencing the IAC? I did notice that when it would stall last night after trying to get it to run, I’m assuming the IAC was making the throttle “tap tap tap” after it would die. Link to comment Share on other sites More sharing options...
gogmorgo Posted February 8 Share Posted February 8 3 hours ago, I_s2k said: Thanks all for the input. You are referencing the IAC? I did notice that when it would stall last night after trying to get it to run, I’m assuming the IAC was making the throttle “tap tap tap” after it would die. If you did this with the map sensor line off and a major vacuum leak you’re going to need to do it again after fixing the vacuum leak, no? On 1/29/2024 at 8:11 PM, eaglescout526 said: Idle Speed Actuator. Its at the front of the throttle body close to the valve cover when looking at the intake from the front of the MJ. Link to comment Share on other sites More sharing options...
I_s2k Posted February 8 Author Share Posted February 8 1 hour ago, gogmorgo said: If you did this with the map sensor line off and a major vacuum leak you’re going to need to do it again after fixing the vacuum leak, no? I would imagine if you adjusted the IAC at all when something happened like with mine where I was missing the MAP hose, yea you’d probably have to adjust it again but I didn’t touch mine at all. I just thought it was funny that whenever the Jeep would stall, the throttle would physically move and create 3 taps. Link to comment Share on other sites More sharing options...
Ωhm Posted February 8 Share Posted February 8 1 hour ago, gogmorgo said: I’m assuming the IAC was making the throttle “tap tap tap” after it would die. True. This is a good thing on ENGINE OFF. ISA is resetting (full extension) for next START UP (≈3500rpms). Link to comment Share on other sites More sharing options...
eaglescout526 Posted February 8 Share Posted February 8 ISA. Link to comment Share on other sites More sharing options...
Ωhm Posted February 8 Share Posted February 8 1 minute ago, eaglescout526 said: ISA. True Link to comment Share on other sites More sharing options...
eaglescout526 Posted February 8 Share Posted February 8 13 minutes ago, Ωhm said: True Lol. I just don’t want the 4.0L guys to get in here and confusing things. Link to comment Share on other sites More sharing options...
I_s2k Posted February 8 Author Share Posted February 8 1 hour ago, eaglescout526 said: Lol. I just don’t want the 4.0L guys to get in here and confusing things. hahaha my bad, I'm to all this 2.5 nonsense. I was pointed in the right direction at least! 2 hours ago, Ωhm said: True. This is a good thing on ENGINE OFF. ISA is resetting (full extension) for next START UP (≈3500rpms). Good to hear! 7 hours ago, cruiser54 said: I'd pick up a new MAP sensor. Make sure there is vacuum at the fitting you're plugging the MAP's hose source on the manifold. New MAP sensor is ordered and should be ready for pickup by the time I get off, I'll update if it makes a change at all. On a side note I did order a TBI "rebuild" and new TPS just in case. After looking at sensor yesterday, its a strong possibility that theyre all OEM or at least very, very old. The TPS is just a safety incase the MAP doesnt change anything and I figured the TBI rebuild wouldnt hurt. Those should be in next week! Link to comment Share on other sites More sharing options...
I_s2k Posted February 9 Author Share Posted February 9 Alrighty so last night I went ahead and unplugged the old MAP to verify that it still would start and run and that it did, still not very good but it stayed running. I replaced the MAP with a new one and unfortunately no dice. I can verify that the old one is the original and I havent thrown it away in case its not the problem but what do you guys think? I did notice the 4 short pieces of rubber that connect to the throttle body, does anybody know how likely those are to leak and if so, do you know the sizes so I can replace them? I also need to verify that the hard line that goes to the MAP isn't clogged. I will say that on the first start up with the new MAP, the Jeep wanted to run, it idled up and held an idle for a few seconds than eventually sputtered and died and now its back to running only when I hold the idle with the throttle. Even when I do that it surges, like a constant up down up down RPM wise. Unfortunately I have the dummy cluster so I couldnt tell you what RPM's it goes to. Link to comment Share on other sites More sharing options...
cruiser54 Posted February 9 Share Posted February 9 Those hoses are super prone to leaking!!! Replace them. Link to comment Share on other sites More sharing options...
I_s2k Posted February 9 Author Share Posted February 9 3 minutes ago, cruiser54 said: Those hoses are super prone to leaking!!! Replace them. Would you happen to know off the top of your head what size they are? Link to comment Share on other sites More sharing options...
cruiser54 Posted February 9 Share Posted February 9 No. Perhaps someone else does. Link to comment Share on other sites More sharing options...
eaglescout526 Posted February 9 Share Posted February 9 When’s the last time this MJ ran and was on the road? What color is the coolant? Link to comment Share on other sites More sharing options...
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