Engine stalling while idling. Rough idle

Hey guys, I have a 1992 MM 2.4L 5speed 2wd. I've been having an issue where I can start my truck right up and it will idle pretty rough and has a cough. it will idle for around 15-20 mins and then it will stall out. It will also stall if i rev the engine and let it drop to idle or if i turn my steering wheel sometimes. I do not have a CEL. I was having an electrical issue and replaced the alternator and reground the engine so I believe power is not the issue. I did a tune up, replaced the fuel filter, cleaned the air cleaner assembly and throttle body. After it stalls sometimes it will fire up again but eventually it will crank but not start. I can come back out the next day and start it and it will fire right up. Has anyone had any issues similar or have an idea of what to check next? Thank you

check the ecm for burn components. next thing would be to make sure the MAF is good. only way to check it is by having a known good one available. you can get the clone/copy ones on ebay for cheap. id bet you its an ecm problem tho. post up a pick of the insides.

you can use this MAF on your 1992.

https://www.ebay.com/itm/Mass-Air-Fl...fyd1f&LH_BIN=1

just be sure and change the plastic plate on the front. if you dont it wont run right.

I will try to take a picture after work. I was fearing it would be ECM but I did flash codes and it is saying nothing is wrong. Can the ecm be shot and flash codes still say everything is okay?

I was thinking map sensor and bought cleaner only to realize you can not clean it without damaging it. I was thinking it would show on the flash codes or a CEL if the map sensor was bad but maybe not.

I meant MAF in previous post

Check the timing when cold and then as it’s having a problem. My bet it coil.
as the coil changes so will the timing.

The ignition coil? That might make sense because the cough and rough idle it has is not random. Its running smooth then rough idle/cough then smoothen rough etc. Then after a while it will stall out. Then sometimes not start back up until a bit later. I might have a few things going wrong to be honest.

http://www.mightyram50.net/vbulletin...id=26379&stc=1http://www.mightyram50.net/vbulletin...id=26380&stc=1http://www.mightyram50.net/vbulletin...id=26381&stc=1http://www.mightyram50.net/vbulletin...id=26382&stc=1http://www.mightyram50.net/vbulletin...id=26383&stc=1

So looks like the ecm is already replaced remanufactured. How does it look? I also ordered an MAF. The truck has 79k miles i cant see it needing a 3rd ecm but who knows...

Thank you it ended up being the coil!

Hello, so i am still having an issue with the truck stalling at low speed or idle. I replaced the coil, distributor, alternator, fuel filter, starter and i also tried a reman ecu. My issue is that the engine runs rough at idle and will stall either at idle or at a low speed. I can start it right back up usually but sometimes it may take 2-3 key full turns to start. Sometimes the key turn sounds like its about to turn and then will not and thern i can try again and it will fire up. Nothing so far has solved the issue. Im thinking either the reman ecu i got was defective, the fuel pump is bad or something electrical. Im really going crazy trying to figure this out. Any thoughts?

Humour me and spray some carb cleaner around all the gaskets and vac lines.

sounds like it could be a vaccuum leak. so either a gasket in the intake side, or a vac line is split.

You are listening to the engine speed, if it climbs up then that area is leaking

oh and the hard starting sounds like the timing is out a bit. possibly been altered to make up for the potential vac leak.

So its not a rough start it just sometimes wants to start and then wont turn over. Next key turn it will fire right up no problem and then sometimes idle for 10-15 mins sometimes shut right off. Im really leaning towards a bad IAC valve. When im at speed it never stalls and runs smooths until i come to an idle or low speed. The tac will jump a bit and then low rpm and then stall. I also noticed when the battery is disconnected for a while and then truck is started again it runs prefect until the ecu runs into whatever the issue is. I will try the carb spray for vac leaks but it doesnt seem like that kind of rough idle or stall. Its a more consistent rough idle/ low rpm and exact shutoff.

Replace the ignition switch !!
You're Welcome :thumbup:

Oh yup. so when you crank it the starter will try turn the engine over but stops.
Thats timing.

can you confirm what you set the timing to?
and did you do the method to put the ecu into the mode to change the timing? (you use a jumper to set it, theres some other info on the site)
you can test the air idle control valve with a mualtimeter, you measure the ohms of it, info in the manual. easy to test that rather than chase a problem with new parts


Do you have a timing light? ou could confirm the timing when it starts up and then if it changes when it dies

So tonight i cleaned the throttle body again and started it up and took it for a ride and drove about 2 miles. Engine must have gotten up to temperature. While driving it bogged out and the tach dropped and then shot back up. Kept going and then it bogged again and stalled. I pulled it off and tried to start it up multiple times and it will not start up. I bet tomorrow when I go back it will fire right up as this has been the case before. I’ll let you know. I am going to take it to a shop and check the compression just to make sure it’s not a shot engine. I will also check timing and whatever else I can think of. I’m thinking maybe the reman ecu I got and installed may have been a dud. Maybe need to send out my current ecu and see if someone reputable can repair it. I’ve fallen in love with this truck but it honestly is only giving me issues since I’ve had it.

Maybe. Sounds a bit like the coil is a dud too. Cutting off like that when warm but fine when cold.

That bit about the tach just dropping and coming back does seem coil related, since the tach is driven off the same signal that fires the coil. Maybe the ICM, if that's still separate from the ECU on FI models?

So the truck had a newer coil in it that I just replaced with a brand new ngk coil that was in a sealed bag. I did order a icm a day ago because I was reading they are a part that fails when at temp and it was cheap. I’m thinking I could have multiple issues. Possibly incorrect timing and then something that is killing spark or possible fuel.

I am too ignorant to try testing all the parts you have Rehashed but YouTube Scotty Kilmer is sometimes helpful for me & although your truck is not 40 years old yet, I still suggest [that if all else fails]
replace the ignition switch & does your truck have fusible links circuit breakers between the battery & main wiring harness (?) If so, maybe they have loose connections or need replacing..?

Most Respectfully & Good Luck
George

When installing the new ICM, make sure to apply thermal paste between it and the plate it mounts to. Should come with a little packet of it, but if not, you can get some from auto parts or computer/electronic parts stores. Autozone stocks it, part #SL203, or Home Depot offers Super-Lube #98003.

Awesome thanks for the tips. Since I’ve been having these issues I have binge watched Scotty Kilmer. He is great I even was thinking about contacting him if I can eliminate a few more cheap fixes. I’ll let you know how the icm goes and any other updates.

when it dies pull the plugs and smell for fuel, if its losing spark they will probably be a little wet

Okay so i didnt get a chance to go to the shop today to work on it because it stalled about 2-3 miles from my house and i was thinking i would give it time to cool off and come back later. I got back to the truck a few hours later and tried to get it started. Turned the key a bunch of times and could not get it to turn over. I was facing uphill at this time and managed to turn it around so it was facing down hill. A few more unsuccessful turns and then on the 4th it started and i drove it home no stall. While in neutral and parked I let it idle for a few minutes and it did not shut off. I turned it off and then tried to turn it back on and same 3-4 key turns until it fired. Did this 3 times and every time it hesitated to start and then finally did. Every time I was not giving gas I was just turning the key. See video below.

https://www.youtube.com/watch?v=A2kBDwzeDlA

LAZY ME not having read through all the posting on this thread is wondering if your truck uses mech or elec fuel pump..? What causes an engine to die (besides all those complicated electronics icm fuel injectors maf TPS etc???)
1) Loss of spark
2) No fuel or fuel problems
3) Failed alternator

SERVICE ORDER
1) Load test battery
2) Test fuel pump pressure
3) Test alternator

Test drive & report any further problems to customer esp if reported problems cannot be duplicated ~ probable replacement of ICM is required if unable to diagnose causes of customer complaints...
Parts: $577.00
Labor: $1,349.00
FACTORY ICM: $721.00
TAX: $98.00

TOTAL $2,745.00

:cloud9: <---- you'll fix it soon

This post about a failing alternator may be relevant to your interests:
http://www.mightyram50.net/vbulletin...ll=1#post78545

I have a new ignition switch coming. I have been able to get my self out of a stall by jiggling the key and trying to start it. Sometimes it will run for the entire time i drive it sometimes it runs rough and stalls until i jiggle just right and start it. I will report back after i replace the ignition switch. I replaced the alternator and was having the same issues. Im really hoping all the issues are stemming from the ignition switch.

Replaced the ignition switch and no luck same issues. Do you think my starter is bad and that is causing the inconsistent start and the stalling? I attached 2 more videos. First is it starting and the second is it stalling. I also adjusted my tps and it seemed to ran better but still stalling and having starting issues.
https://www.youtube.com/watch?v=0EwA-IQ1SY4
https://www.youtube.com/watch?v=oaM6r-UIdn4

Does your truck have wire type fusible links coming off the + battery terminal that supply 12V to the wiring harnesses; maybe a bad wire or loose connection..? I posted plenty photos of "fusible links" check those photos

Only recently have I learned that the big red cable on the + pos battery terminal is ONLY powering the starter motor ~ smaller wires off the battery power all the other stuff ~ themz is what needs checking to be sure 12V power is being constantly supplied ~ some guys hate Scotty Kilmer auto mechanic on YouTube ~ maybe google search him diagnosing a similar problem as yours
Good Luck & Enjoy the Fixing
Aloha ~ George

That starter sounds like the pinion isnt retracting properly and the solenoid is ticking
you might pull it out and inspect the flywheel ring gear teeth (engines tend to stop at the same spot, so it might be that the teeth in 1/4 of it are damaged, sometimes it gets past that section and starts)
and also check that you have the correct gear on the starter, and that it is moving in and out.


but i dont think that that is the issue, it still sounds to me like the timing is wrong when starting. do you have a timing light?
too advanced timing will give that kind of starting and run "ok"


you should check the pully to see if its wandering, and maybe inspect the timing belt and tensioner, a bad tensioner will let the timing wander about by a few teeth
a bad harmonic damper will also wander around abit

i say that because the engine seems to run fine (belt is tensioned by the engine spinning) and then it sounds like its kicking back when you try start it (slack belt has altered the timing) if its then wandering when the idle speed drops, it loses its timing and stalls out

hard to diagnose over the internet of course

another thing iv been suggested is an internally corroded positive battery cable, giving intermittent high resistance


but consensus is that the timing is out

Rehashed ~ your truck is fuel injected, right ? What have you done to ensure its not a fuel problem ? 4G64 is that 2.0 or 2 4L engine ?

yes fuel injected 2.4L. I changed the fuel filter. I bought a fuel pressure sensor that I will be replacing this weekend. I also changed the icm did not fix. I am also going to put the original starter back In. I had switched I thinking it was bad but it ended up being the neutral safety switch on the clutch pedal broken

its kicking back on the starter, Its textbook trying to crank against an ignition stroke.
Check your timing, either retard the distributor a little, or soemthings up with the reluctorwheel (these engines had both but i think you would have the distributor for that year)

Quote:

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Originally Posted by Rehashed

yes fuel injected 2.4L. I changed the fuel filter. I bought a fuel pressure sensor that I will be replacing this weekend. I also changed the icm did not fix. I am also going to put the original starter back In. I had switched I thinking it was bad but it ended up being the neutral safety switch on the clutch pedal broken

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THANKS FOR THE FEEDBACK ~ YOUR TRUCK IS DRIVING ME NUTS :smileyinthebox: TORTRON :eek1: ACTUALLY, SEEMS YOU'RE LEARNING A LOT MORE ABOUT THESE THINGS ~ CAN'T WAIT TILL YOU FIND THE MAIN PROBLEM ~ SERIOUSLY, CHECK OUT SOME YOUTUBE VIDS ABOUT THIS ISSUE, MIGHT GET LUCKY ~ WISH I COULD HELP MORE BUT MY TRUCK IS CARBURATED ~ I THINK SOMETHING IS CAUSING THE ENGINE TO RECIEVE EITHER TOO MUCH FUEL OR NOT ENUFF FUEL (SIGNALS TO THE FUEL INJECTORS FROM A BAD SENSOR?) OR, SOMETHING IS CAUSING AN INTERMITTENT LOSS OF ELECTRICAL POWER SOMEWHERE ~ A TIMING LIGHT & TACHOMETER IS HELPFUL TO FINE TUNE THE ENGINE & MAYBE USE THE TIMING LIGHT TO SEE IF TIMING IS ADVERSLEY AFFECTED WHILE REVVING THE ENGINE OR IF IT CHANGES AS THE ENGINE DIES (?) AM WONDERING WHAT YOU CAN DO TO CAUSE THE ENGINE TO DIE (LIKE DOING A DEMONSTRATION TO THE REPAIR SHOP TO PROVE THE PROBLEM EXISTS) IF YOU CAN DO THAT THEN THE PROBLEM IS NEARBY ~ AM BEGGING FOR YOU TO GIVE UP & SELL YOUR TRUCK TO BUY ME A PAIR OF YAMAHA PWC 'n TRAILER <----- JOKING BADLY ~ HAVE A GREAT WEEKEND PLAYING 'n FIXING
http://www.mightyram50.net/vbulletin...id=26509&stc=1

@xboxrox i make good money buying cars and motorcycles that "dont run" and getting them going within a few hours. You just have to go through methodically,throwing new parts at something without finding the root cause is probably the most stressful way to do it

Yea I am definitely doing this the most stressful way. It’s just difficult because my problems are intermittent and I think I have fixed and tuned up the truck it runs better and then it always comes back and has this stall. Do you think all these symptoms could be from the timing being off. I’m going to do the timing tomorrow. I do not have any codes which hopefully is another good indicator of it being timing and not a sensor of some sort.

The rough starting sounds like every time i have had a car with the timing out, the way it runs and dies would also make sense. Its something thats easy enough and free to check

(but you know, diagnosing over the internet is hard, i actually walked my brother through getting his new barnfind (23 years sitting) running last night over the phone, so sometimes it works)

My truck had a carburetor float that leaked & sunk in the fuel bowl causing flooding & no start ~ one year later & a ton of parts thrown at the problem could have been avoided had I known the float was the only problem a $15.00 part 'n 2 or 3 hours labor ~ live & learn

Update. I found my issue and it ended up being something that I had addressed early on but missed. The female end on the connector from the main harness to the coil. One side of the inside of the female connector was bent and wasn't making good enough contact at all times causing the intermittent issues. I used a little pin and pushed the contacts closer and she fires right up no issues no stalling. So good news is i made sure timing is perfect its running incredible now. I likely cleared up issues with the full tune up as well so im not unhappy with how it all worked out. Thanks for all the help and ill update the post with anything new!

:thumbup: X10