Hi, I was driving along at around 65mph when the engine suddenly died. It made no other noises and it acted as if the ignition just quit. Plenty of gas in the tank.
I tried pumping the pedal a few times while it was in gear and still moving fast with no results. I tried pushing in the clutch and using the key to try to start it and no firing at all. A friend towed me to a parking lot and I again tried several times to start it with no firing at all (engine cranked over normally).

The next day, the temp was around 20F and I again attempted to start it and this time it fired up as if it was flooded. As soon as I would change the ignition key position back from Start to On, it would die.

Can smell gas, so I believe that the injectors are probably working.
There is a nice blue spark, about a 1/2 in long.

Any ideas?
Could it be the ecu?
Is there a way to have the ecu checked out?
Will try new plugs in case the old ones got too wet when I pumped the pedal while still moving along.

Thanks again.
BuffVail

It is a 4-dr with AC and a manual tranny

PS: Just pulled the plugs and cranked it over to clear out any gas. It appears the injectors are running all the time and just pouring gas into the cylinders.
Is this most likely a ecu problem?
How do you check such a thing?
Thanks

 

I know nothing about ECU issues but the thing that is curious to me is that you say it fires up while you have the key in the start position. I also assume the sparks you saw were while cranking. Does this always happen - that it fires up in start and stalls when you go back to "ON"? If so it could be a problem with your ignition switch or wiring.

I don't know whether the '90 model has a coil and distributor or a coil pack and crank sensor set-up but either way, if you can find the +12 wire that feeds the coil(s) and put a test lamp on it you would see if you're only getting ignition voltage while cranking. If so then you should be able to trace it back to the fault. Or somehow supply +12 from another source (with a fuse) so you can drive it somewhere to get it checked out.

Let me know if this helps.

Ron

 

Actually it only fired up with the switch in the Start position when it was cold outside and it sat overnight.
Now it appears that the injectors are spraying continuously and the plugs are so wet, they will not fire at all.
In fact, with the plugs removed and the engine being cranked over, the gas start flying out of the spark plug holes so much that the floor gets wet.
Thanks for the reply.

 

ecu,ecu, go to a pick a part,pull one and try, appx $20.00 at junkyard,the same thing happend to me

 

Thanks a lot. Do you know what different years and models use the same ecu?
Or, do you know how I can find out?
Thanks again

 

Check the number on the ecu unit,i think from 89-92 it was the same,i have a 4 door auto and it died on the freeway just as yours did,it sat a year ,i went and changed all kinds of the componets,only to replace a used ecu,and it fired right up,let me know if it works,your ecu controls all stages of ignition,also get a warrenty from the junkyard {$5. 00} xtra so if it dosent work switch it out with another one,i got two at the junkyard just in case,im in so. cal and theres lots of places to get um cheep.
Hope this helps
Greg

 

Hey Greg,
Thanks a lot. I live in Colorado in the mountains and I will try to find a auto salvage yard somewhere that offers a pick and pull type deal.
Probably will have to go to Grand Junction or Denver.
Thanks again.

 

90 model montero's were very consistant on a no start issue. 90% of the time it was the ecu. the factory ecu was junk. factory replacements will never fail again. they were much improved. the other 10% were timing issues. sometimes the timing belt would break due to lack of replacement, or sometimes a few teeth on the belt would come off, again due to lack of replacement, and jump time. some times it wasnt enough to make it not start but to just run really bad and have no power on acceleration. if your ecu swap doesnt work take off the top timing cover and taske a peek at the condition of the belt and roll the engine around to see if the marks line up. good luck, and keep us posted. greg...

 

DONT get a junkyard ECM. they all suffer the same issue, which is leaking capacitors.

do a google search and youll find many places capable of repairing yours.

 

It used to be things were made with dipped tantalum capacitors but they became expensive ... so they started making them with cheap electrolytic caps that leak and fail. PC motherboards have gone the same route.