What year is my motor????????///88 or 91

Hello. New to this forum. I have an 88 MM. Atleast thats what the door says and the title. The motor is fuel injected, Vacuum diagram on hood says 2.4l motor, If someone did a full motor swap they did a very good job because it all looks factory absolutely no hack job here. I was also thinking someone may have put all the fuel injection equipment on a 2.0 motor. I will try and post up some pictures right now of the engine bay. If you got any ideas what exactly is frankenstein on my truck please let me know.

The truck should have came with a carbed motor. Either someone put a 2.4 in your truck, or swapped fuel injection stuff and wiring/ecu and put it on the 2.0. To see which one it is, look on the pass side of block behind water pump. Should be a flat plate on side with engine code written on it. G63b is carbed 2.0 and 4g64 is f.I. 2.4

It says4g64....thank you. Any advice on noisy valvetrain. My truck was sounding like it had a stuck lifter or it was way out of adjustment. I put in some oil detergent (additive) yesterday and it seemed to help.Any input or advice would be greatly appreciated. Is there any way it could have come factory it just looks completely factory under the hood.

No, no way an 88 would have a 4g64. Its not hard to make it look like it came factory, look at my turbo eclipse swap build thread, looks like it came in the truck lol. On the valvetrain, you probably just need to replace the hydraulic lash adjusters

^
Your '87 is fi factory?...
I was gonna try and help with a 'vin decode'
thought, however I just ran the vins on My '88
& '93---
Hahahaha, both show automatic equipped.
(both are 5 speeds. lol)

On to the 'lifter' noise...
Interestingly enough I just did a full synth change
on the '93 and now have the dreaded 'tick' where
none before.

lash adjusters (if needed).
here
for about $60 shipped.

Mitsubishi pickup truck, or are you talking other vehicle? In the US, No MM came with Fuel injection until 90, possible late 89 if you got a 1990 early. Even the factory sales brochures state so.

That's odd, haven't heard or seen that, even all the parts stores/sites and Mitsubishi dealer sites don't list a 2.4 until 90