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the cold start shuffle got me

Posted By: keetz

the cold start shuffle got me - 04/12/22 01:32 AM

So i've looked back through this forum and the mitsubishi forum and I've read about the bad startup condition on the 89, but many people say that is different from what occurs on the 90 and 91 given we have injection and some other do dads.

I've had the valve click since I got my 91 monty 3 months ago and I've been debating over getting a whole new engine or just new heads, but I've been busy buying all the very needed suspension parts and hoped I wouldn't have any major engine issues until I get to it. I never had any issues on cold startup - even in 5d F weather - it smells real bad and I know that I've got a couple of cracks in the exhaust but it's started just fine for 3 months.

Today when I started it up, it lugged and wanted to die - did the classic choke and shake and I saw my "check engine" light illuminated for the first time outside of ignition sequence - it lugged for about 2 minutes and I gave it gas every few seconds to keep it going - once it warmed up, the idle evened out and the check engine light went off - It gave me a little bit of trouble in the first quarter mile driving it but no issues once the temp got up to 1/4 (where it has always lived in my ownership)

What would you place your money on? My MAF is clean and good - that was one of the first things I checked when I got the vehicle. I've had a sneaking suspicion that the oil pump might be going out but I really have absolutely nothing to base that on other than the previous owner didn't take care of it at all. I read the IAV can be an issue as well as the ECM but I would think with ECM it would be more of a bugger than simply going away once it warmed up. I don't have the tools to check cylinder compression or vacuum but would one of these go away after warm up? Is it possible there's a timing chain issue? Outside of feeling like low compression and sounding like a misfire - it sounded almost like something was ....."flapping around"..... in there and that went away when everything clicked into place.

Like I said - I'm still debating whether to get new heads on it but I don't wanna drop money for heads to only find out the bottom end needs rebuilt when I could have just gotten an entire new engine. Either way, I'll try to get a definitive answer on what's going on but it might be fun to see who's correct in the end and maybe it'll turn out to be some dumb sensor and I can procrastinate another month or two on the engine replacement (crossing fingers bc I really wasn't budgeting for that until November-ish)
Posted By: Mudraider

Re: the cold start shuffle got me - 04/12/22 10:34 AM

So, what was the code? D>d you check it with an analog ohmmeter? Procedure is outlined in the FSM available for free download at mitsubishilinks.com.
Posted By: keetz

Re: the cold start shuffle got me - 04/12/22 04:30 PM

Ignition coil was bad - I'm still going to check the stored codes when I have more time tonight, because i"m still not certain this is the only problem. The ignition coil that went bad wasn't factory and I see that the previous owner already replaced the distributor and the key ignition at some point leading me to believe this has been a problem in the past. What would constantly burn out ignition coils? seems to me there's probably a short happening somewhere, which isn't surprising because I've found and replaced two bad wires already - but what would be enough to burn out the ignition system?

The plastic shielding around the ignition at the steering wheel had a bad gap in it that I closed up right before this problem occurred - would there be anything in there that they might have purposefully been giving more breathing room for some reason? Maybe I crimped some wire that they meant to replace and hadn't gotten around to it? Also, i don't know if it's coincidence that I happened to do it right when the engine was getting warm enough to run okay, but when I was experiencing the problem yesterday I thought to flip my cabin fan on high and things smoothed out quickly afterward - the engine is not overheating though (at least the thermostat doesn't tell me that it's overheating and I ran it for 30 minutes without anything steaming or smoking).

i'll keep diving - will update with any stored codes I can pull later on
Posted By: Mudraider

Re: the cold start shuffle got me - 04/13/22 12:53 AM

Originally Posted by keetz
seems to me there's probably a short happening somewhere, yes
- but what would be enough to burn out the ignition system? 30+ year old wiring, thousands of heat cycles

would there be anything in there that they might have purposefully been giving more breathing room for some reason? No.
Posted By: keetz

Re: the cold start shuffle got me - 04/16/22 08:37 PM

The code that I pulled back was 23 - which would be No1 Cylinder Top dead Center sensor -

It's possible I misread the code and it was actually 22 - my volt meter gave me two long 12v. spikes then two short 12v spikes then a short pause and another short 12v spike before going through the cycle again. Is it possible this is actually 22? which would be crank angle position sensor? I'm pretty sure I read it correctly as code 23 but i'm curious as to why the three short spikes weren't evenly spaced apart before going back to the long spikes for the first digit of the code, but in any case not sure what to do next. I'm not familiar with the TDC sensor or where it is and the issue is still occurring.

ohh - also I read the code by putting my positive on what I believe to be the #1 pin (as I'm looking straight at the diagnostic harness, the pin farthest to the driver side on the bottom) and instead of putting my negative on the opposite ground pin on the harness, i put it on a known good ground on the car chassis (i used a ground spot under the glove box that's used for the one of the ECM wires) - when I tried my positive to the 1 terminal and the ground terminal on the top row far right, it didn't give me any readable voltage pattern.

Posted By: keetz

Re: the cold start shuffle got me - 05/02/22 12:06 AM

I've been tinkering around a little more with this - got a really dumb question and a couple of reasonable ones: - the CEL went away for a few days and then came back on - I got a slightly better multi-meter but this one auto reads between MV and V so it's harder to tell the actual digits, but I think I may be getting a code 25 instead of 23 now....whats a good way to link a video here so i can get someone else's take?

Also, What exactly is the top dead center sensor and where is it located? I can't find this illustrated in the service manual anywhere nor can I find a part name or number for "top dead center sensor" for this vehicle. Is it called something else now? Please help.

Third - I replaced the ignition coil and the water temperature sensor and I noticed that the water temp sensor doesn't screw all the way in - my old one looked super corroded on the top three threads that stick out the top and the new one only screwed in the same amount - seems like this is how it's supposed to be but wondering if there's any kind of sealant I should be adding to the threads to ensure it works correctly and doesn't leak.

Posted By: Mudraider

Re: the cold start shuffle got me - 05/03/22 07:20 PM

What manual are you using? A Haynes manual? Try here; mitsubishilinks.com
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