Logan81Pickup

Took my truck for a drive today. It SEEMED to run fine, but it could barely get up to 70, and when I got home it was overheated. The oil light came on a few times too. Oil pressure was fine and it was full of oil when I checked it.

Not sure what to do.

Edit: I forgot to mention it's an '81 with the 22R, and I just changed the oil pan gasket the other day. Also there was water leaking through the bottom left corner of the windshield, and it was contacting the fuse box, so that might be why the oil light was coming on.

It was also cranking harder than usual. Part of me thinks it could possibly be a timing issue. The engine is lacking in top end power mostly.

Logan81Pickup

Took disty off and she was all melty D: I think (THINK mind you I have almost no experience with distys) that the central point wore to the point that it was arcing and ended up melting all the plastic. I'm going to pickup a new distributor cap and that spinny thing and see if I can't get her to run properly.

MudHippy

I'll second that. Nice job with the diagnosis. Keep up the good work!

85TurboRunner

That spinny thing is the rotor. Don't say spinny thing at the parts store.

Logan81Pickup

And now after replacing the distributor cap I'm getting a loud knocking sound when I get on the gas from 3-4.5k rpm. It's coming from the engine. (durr). I'm going to check all the spark plugs tomorrow I guess to see if it's missing then I don't really know what to check after that. I still think it's a timing issue since it ONLY shows up at 3-4.5k rpm while applying throttle. The motor still feels weak though.
I also hit the rotor with a wire wheel so hopefully it'll get a little better connection now.

But here's a picture of the distributor cap compared to the new one to keep this thread substance filled:

MercuryMan

Yea the old was toast. Before you drive any more do a compression test. If you don't have a gauge you can go to Autozone or O'reilly and use their 'loan a tool' program, deposit down and returned when you bring it back so its free :-) Do a dry test and if the numbers are low do a wet test-good starting point.

You need to do a basic analysis before you keep churning away and potentially doing damage. Your timing chain might have jumped, you might have a fried ignition (could be a number of things you haven't replaced yet), you might have ring issues and your compression is dropping, could be valves needing adjusting too, possible oil pump issue also. Have you checked static timing when you replaced the rotor and cap? What about dynamic timing with a light?

nightstalker

I always replace the rotor with the dist cap, their cheap, and its cheap ins. Although, I expect you have bigger problems. Good luck

Logan81Pickup

Did some more testing today and went for a test drive. Went to turn around and my engine siezed up on me D:

If I had to guess I'd say it had something to do with the oil pump, since I just had the oil pan off.

MudHippy

Ouch! I'm sorry to hear that.

Logan81Pickup

So since I'm going to be pulling the engine anyways... I've been thinking about doing a 20r/22r hybrid, and removing all the emissions stuff I can from my engine bay. It is my understanding that I need an 81-84 22r block (in my truck) and a later 20r head. I haven't even started on pulling my engine yet, since I've got to find a place to put all the stuff anyways.