87 mighty max 2.0 intermittent timing issue?

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11-13-2018, 07:01 AM
Milyko84

87 mighty max 2.0 intermittent timing issue?

Hey all first post here and stoked. Love a mighty max. Was my first vehicle 20 yrs ago. Anyways just bought one for 400. Dude didn't know what was wrong with it. Loss of power and ran rough. When I checked it out it took a bit of pumping gas pedal to fire but she did. Ran rough at idle but when idle up it smoothed and and engine sounded fine. No knocks or pings. Took it around block and yes loss of power. I was willing to gamble and bought it. Drove it on the tow dolly fine and got it home... a week later tried to fire it up again with ether and fired right up and sounded smoother at idle then before. I didn't drive it because didn't have time. I work away 2 weeks at a time so fast forward 2 weeks. Tried to fire again to get it to mechanic and it just turned over forever and ether didn't help. So called for a tow... tried one more time before tow and it fired right up no ether but was running SUPER rough. Sounded absolutely terrible. In first gear couldn't get it to move cause no power at all and it would die.... timing must be off no? But to be intermittent like that? Distributor? I appreciate all your time you all pour into this site and I'm super grateful I found it. G63B engine. Thanks!
11-13-2018, 07:22 AM
Giovanni89

Intermittent could be mechanical too. A sticking valve... I would do a compression check first just to make sure all cylinders are good. Doing it after a failed attempt to start would be best as it is an intermittent problem. Take a good look at the spark plugs when you remove them as well. Black and it's running rich. Heavy black buildup is usually oil. Very light would mean that a cylinder is probably running lean.
11-13-2018, 07:28 AM
Milyko84

Roger on the compression test first and check the plugs .... I'm not a mechanic so will let my man know. Thanks dude
11-13-2018, 12:42 PM
geezer101

OK the distributor too could be on it's knees. The vac advance solenoids on them can and do split which nerfs advance on throttle plus the counter weight springs in the mechanical advance can break as well, creating an erratic ignition curve (lots of fun to drive...) Might be a big ask but maybe hit the JY's for another distributor. You can substitute a lot of different distributors onto the G63B engine from older Mitsubishis or Hyundais that used Mitsu engines. The G6XB engines were used in a lot of cars and mini vans like the Colt Vista but try to make it easy on yourself by finding one that needs minimal modification and cosmetically looks similar if you have no luck in finding one from another 2.0 MM.
11-13-2018, 01:38 PM
Milyko84

Quote:

Originally Posted by geezer101

OK the distributor too could be on it's knees. The vac advance solenoids on them can and do split which nerfs advance on throttle plus the counter weight springs in the mechanical advance can break as well, creating an erratic ignition curve (lots of fun to drive...) Might be a big ask but maybe hit the JY's for another distributor. You can substitute a lot of different distributors onto the G63B engine from older Mitsubishis or Hyundais that used Mitsu engines. The G6XB engines were used in a lot of cars and mini vans like the Colt Vista but try to make it easy on yourself by finding one that needs minimal modification and cosmetically looks similar if you have no luck in finding one from another 2.0 MM.

I see the dude Bought it from put a new distributor cap on put the original distributor is in there. What about having them sent in to be rebuilt for $180? Or that spring you speak of ... can that just be replaced? Thanks!
11-13-2018, 03:44 PM
Milyko84

Also is there a way to trouble shoot to see if the it is indeed the distributor?
11-13-2018, 07:26 PM
Giovanni89

A timing light should help you diagnose a wonky distributor. I'm going to assume you have little to no mechanical experience based on your earlier post, but you'll learn at least the basics owning a 30 year old truck!
A timing light is a strobe light that flashes with the spark on the #1 cylinder. There is a mark on the crank pulley, and a scale on the timing cover. The strobe light will light up that mark every time the cylinder fires so that you can read where the timing is. Your base timing is probably between 5-10 degrees Before Top Dead Center. If your distributor is sticking, it may not come back down to that at idle, and you would see it with the timing light. My suggestion, if this isn't your only vehicle, is to invest the money you would spend at the mechanic on some tune up tools. There is a wealth of information available here, and I'm sure there are many people who could walk you through troubleshooting the basics and getting the truck running right
11-13-2018, 11:30 PM
geezer101

Quote:

Originally Posted by Milyko84

I see the dude Bought it from put a new distributor cap on put the original distributor is in there. What about having them sent in to be rebuilt for $180? Or that spring you speak of ... can that just be replaced? Thanks!

If you look in the right place you can get a bargain. As I mentioned there are a ton of cross compatible distributors around and sometimes it's way cheaper to buy a reman'd unit off the shelf. This should be a good place to start -
https://www.ebay.com/itm/Trak-Cardon...YAAOSwv6Fbu29~