318 running poorly -

[Dave_1972]

The 318 in my M880 is around 95,000 miles (if the OD is accurate) and has picked up a few bad habits this year.

Smoking (blue-gray smoke) on start.
Rough idle.
Pinging under heavy load.

I have my yearly off-roading trip coming up in October and need my tow rig in good working order. I am trying to decide if I should go down the road of troubleshooting the issues in this motor - or just pull this 318 and swap in the 318 from the parts truck I just broke down.

That 318 purred like a kitten before it was pulled. I have a new fuel pump and aftermarket water pump on my engine that would need to be swapped over also.

I also have an option to pick up a 1990 Dodge with a fuel injected 360 for $500. Engine supposedly runs great in that rig but the P/O will be keeping the transmission. So at a minimum I think I will need to buy a torque converter. If I were to go that route - what else would I need besides a torque converter? Would there be some wiring changes I need to make?

Money is a bit tight as I am trying to get a new set of 35's for the trail rig also. (96 Cherokee)

 

[M543A2]

Pinging under load and rough idle might be related to timing having gone too quick. Blue smoke at start-up is usually evidence of valve guide wear/valve stem seal problems. Try timing it with a light. If you cannot get it set right without missing, then timing chain might have slipped. Check distributor cap for cross-firing, carbon tracks.
Regards Marti

 

[tbone1004]

agreed on timing. Sounds like you're too far advanced. Your distributor may have slipped or skipped a tooth in the timing chain and caused some detonation problems which can wreak havoc on the valves. I'd put a timing light on it and check the advance. Should be in the 14*btdc range, +- 2*. If it is at that point and doing those problems a rebuild is in order and I would just put the 360 in there.

If the 360 had an automatic, it will bolt right in. The 318 was balanced internally and the 360 externally so if you can get the torque converter from the 360 you'll be in good shape, maybe offer to swap transmissions since the torqueflight transmissions are otherwise identical.

As far as wiring goes you'll have to look at the wiring diagram for the dodge and see what computers the 360 needs, mainly if the tranny in there was computer controlled. I'm not familiar with that vehicle, so am not sure off hand. If the EFI is purely engine based, then you'll just need to make sure you put all of the sensors in there, so take the whole exhaust system from the truck if you can to get the O2 sensors and what not.

 

[Dave_1972]

The 1990 had an automatic but it was 2-wheel drive rather than 4-wheel drive. I'll see if I can check the timing this evening. This will be the first time I've done that - I assume the Haynes/Chiltons manual procedures are pretty straight-forward for that?

I have the military manuals also - not sure if that procedure is in those.

 

[tbone1004]

timing is pretty simple. Just youtube a couple of videos. If you have an induction timing gun it makes it a bit easier since it just clips over the #1 wire, then just aim at the harmonic balancer/crank pulley. You should see a welded tab that comes off the block and you'll see a mark on the pulley. Any of the manuals should have it in there. Just check the timing first, and if it is off, then unbolt the distributor to turn it. A lot of youtube videos on how to do it. Not necessarily on that particular engine, but timing is timing...

 

[WVCB]

The worst part of timing the 318 is getting to the hold down bolt on the distributor. Pretty much have to have a distributor wrench or fab one of your own. Not designed for accessibility.

 

[WVCB]

BTW, my 1977 W200 had the same symptoms and it was the timing too advanced. My manual calls for 10BTDC and that's what I set it at. Took care of everything but the smoke, which is a different issue.