Howdy. Happy Thanksgiving!

So I have this 2001 Montero XLS 3.5L that occasionally won't completely start when it's cold usually, sometimes when it's warm weather too. I put the key in and it cranks strong but won't start. Sometimes, actually most of the time when it does this, I can remove the key fully, put it back in and turn and it'll fully start up on the 2nd or 3rd attempt. However, sometimes I have to rev the motor for a few seconds to 1500 - 2000 RPM to keep it running, else it will stall very quickly without notice after it does it's initial rev to 1200 or so RPM. After it's warm and been run for a few minutes it seems fine and doesn't do it for the rest of the day unless several hours (like 7-8 pass) between starts.

This is what's weird...
When it doesn't start on the first try, if I don't entirely remove the key and reinsert, it NEVER starts up on subsequent attempts. I have to at FULLY remove the key and reinsert it. If I only turn the key to the rear of the car part way, like where it rests in accessory mode...IT NEVER fully starts.

Sometimes, when it's damp and cold, it won't start for several days, and then after it dries up, one or several days later, it will start again just fine. I think the dampness and cold adds something else into the mix, but I'm not entirely sure. It's only given me problems with starting for several days twice since I've had it for 3 years. And I'm pretty sure on each occasion it was damp and cold, not just dry Colorado cold. The 2nd episode was just the other day. It will sometimes give starting problems in the warmth, like in Summer, but it always starts on the 2nd or 3rd or 4th try (at most) when dry and warm.

This could be a number of things i imagine from fuel problems to spark/electronic. I'm wondering if anyone has really solved this issue and know what it can be, and what it shouldn't be with my exact symptoms.

I've checked my air clear and air flow and it's getting intake air, best I can tell.

I haven't changed the gas cap either. But i'd think it would work fine or wouldn't, not work fine 90% and not 10% not, and randomly at that.

I don't think the in-tank (what a dumb design!!!) fuel filter has been changed (185,000 miles) either but it doesn't make sense to be a filter if it will start after several days. Filters usually get clogged and stay that way. But maybe something else could be contributing the the filter's performance like moisture, fuel pressure, or outside ambient temp or air pressure?

There aren't any motor codes.

Anyone solve something like this before?

Thanks!

 

This is a tough situation to troubleshoot. The fact that the condition is exaggerated during damp or cold events, I suspect it is in some way related to wiring/electrical issue. To eliminate the other possibilities, try the following:

when vehicle works, check the live data feed on fuel trims (you may need to borrow a scanner that is able to do this). Check fuel trim data (both short and long term) at idle and see how/if they change when you rev the engine. Post data back here.

Since it cranks during no start, you can eliminate the Neutral Safety switch (if it was bad, it would not turn the engine over).

When you have a no start condition, leave the key in (do not remove it completely as you do now), open hood and wiggle the connectors on the various sensors - MAF, MAP, camshaft position, etc. Try to start again and see if it made any difference.

Since removing the key is helpful to "fix" no start, you may have an issue with the ignition switch. Try to wiggle they key up and down, in and out while cranking when experiencing a no start condition.

As far as the in-tank fuel filter. it is pretty easy to replace it. There is an access hatch under the passenger side of the second row of seats. This way you don't need to drop the tank to get to it.

 

OK awesome. Will do that live feed check. I need to buy a system reader that does this for Mitsubishi and Dodge Ram too, if possible. Any recommendations?

I had no idea there was an access hatch for the fuel fuel filter and pump. Glad you mentioned that! I thought the tank had to be dropped!

 

Today it started and ran fine at first after sitting for 3 days. Moved it to trickle charge battery for a few hours. Got a full charge after 4 hours. Went to start and move it and it did its no-start thing. Did it twice, and on third time I got it to rev up but then it immediately died again. Fourth time I took key entirely out flipped it over, reinserted and it started like it should. Previous 3 times I hadn't done this...i just took it out and straight back in, wiggled it in ignition.

My vehicle battery is 6 years old, just noticed today. I think it's maybe weak and not putting out a consistent enough voltage for the fuel relay to stay energized or pump to stay on (or both). I have a spare good one I'm gonna toss into tomorrow and see if this fixes problem random no - start.

Between 2nd and 3rd tries I noticed the OEM dash alarm light would blink fast for about 5-10 seconds and go off, after the failed start, with the key out of the ignition. So I got out of the car, locked it with the key and the light stayed steady on for a few seconds and then blinked very slowly after that (when it's armed it does this I read in manual). So I unlocked the car, got in and then it started with a manual throttle rev but died. Then I removed key and turned it over and reinserted and it started fine.

I removed the key's button cell battery and it tested fine.

I assume if the battery is putting out degraded power that it can cause many things to act funny even if it's good enough to activate the starter (which it clearly is). I'll test the battery voltage tomorrow and see how it's reading at face value. Strange that after I charged the battery for 4 hours it didn't start...so kind of doesn't make sense it's the car battery in that way.

Annoying! Lol

 

I have a software for PC that allows to see/graph various parameters for the engine. It works for all sorts of OBDII vehicles. It is AutoEnginuity ( www.autoenginuity.com ) The initial hardware and the software package is about $250. This will do all basic PCM diagnoastics on all vehicle models. You can get expansion packs to have more in-depth coverage of ABS, Emmisions and some Transmission codes. Those go by manufacturer and will be extra cost.

On the other hand I recently got an inexpensive ($40+) code reader that is capable of reading live data from most OBDII vehicles. Here is a forum thread on those: https://mitsubishiforum.com/forum/mi...s-3-0-a-51296/
It is not as useful as the "big" software I have, but it is fairly cost effective and will do the job.

 

I have a 97 3.0l as a second car w/ 265k miles that was doing the exact thing. No dtc set and unfortunately never anyone home when it happened so I could check wile cranking. I threw a hand full of parts at it but I think the winner was a new ignition switch. Mine was a no start or sometimes a stall no start always shortly after start up. other things I changed just for the fact that they hadn't been changed was the fuel pump and ignition module. I seem to remember that when the failure happened that the radio also went dead. That and the no dtc thing made me think ignition switch. this was a daily driver for the better part of 20 years.

 

I am thinking mine may also be a low-fuel-tank-level-on-forward-facing-hill problem, haha.

This one has done this before when left facing downhill of 20 degree slope for a few days. I just remembered that. The tank was about 1/3 full then.

So it was in the last 1/8th of fuel tank level (per gauge) and was facing downward maybe 10 degrees this time.

So don't park your SUV facing down or uphill for more than a few hours, lol.

But I'm not sure. Watching it now for a couple of days. Put gas in it and charged battery. Will change battery if does it again if after tapping on the fuel tank's bottom doesn't work.
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So ignition switch and alarm defect will be added to watch also.

I hate throwing parts at stuff! I end up breaking more stuff like that usually while doing it, lol

 

My reasoning for the switch was no dtc set and figure 18 years of daily driving is a lot of off/on cycles, and I'm almost positive that my radio went dead when it happened (but I can't confirm that). mine also stalled a couple times about a block from home while driving. It didn't sputter, just dead off like you turned the switch. It also cranked fine, but wouldn't hit a lick. My Mitsubishi MUT2 scan tool data looked normal so at some point it just came down to throwing suspect parts at it, and with 265k on the odometer I just looked at the fuel pump as regular maintenance. FWIW, the inside of the tank was crystal clean.

 

Wilde, It is possible that you have more than one issue there and that is why behavior may seem more random or less predictable. I agree with 6500rpm, that the ignition switch is #1 suspect. However, low fuel level may also contribute to the issue. However, I don't think that would be influenced by the changes in weather.
Change ignition switch and see how it goes from there.

 

Will do after swap battery on next occurrence, and if that doesn't fix then relay that may be weak also if persists.

i'll look for replacement tips here because I've never messed with steering and ignition stuff before.

Thanks!
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