I got a running, driving, good mechanical condition '79 244 a couple of months ago as (essentially) a wedding gift and it has refused to start for me as of two weeks ago. Hopefully someone can back up my assumptions and/or point me in the right direction.

Symptom:
-Turn the key and the engine turns over but does not start.

Troubleshooting/testing:
-There is fuel in the tank
-Both fuel pumps work when the fuse panel is jumped
-All door pillar fuses replaced and fuse holders cleaned with wire brush
-Fuel pump relay was burnt internally and replaced with a known good unit
-Cracked Vac lines have been replaced, others visually inspected
-Removed fuel filter and cranked engine, no fuel. Jumped fuel pump, fuel gushes.
-Opened fuel-pump relay and watched for operation on ignition, no fuel/no switch. Operate relay switch manually (pressed closed with screwdriver), fuel gushes.
-When cranking engine with fuel pump relay manually engaged, the engine still will not start. Assuming engine is not sparking.

Since this seems to be an electrical problem of some sort and I've already verified the relay is good, I'm leaning toward the electrical portion of the ignition switch as a next step. I'm planning to pull the known-good switch from my '89 240 in the next day or so to test it, but any other thoughts or suggestions would be very helpful. A new fuel filter is going in as well since I've already broken loose the god-only-knows-how-old current filter. I'd be happy to clarify if any of this doesn't make sense since it's 5am.

 

K-Jet In Detail | K-Jet.org

200 Series | K-Jet.org

BTW your engine is B21F. "Pretty much" same system from 1978-1982

 

Don't assume the engine is not getting spark. Verify the coil resistance and voltage and then check for spark.

-are the plugs wet with fuel?
-is your camshaft turning? (timing belt still there?)
-does the needle on the rpm gauge jiggle when you engage the starter?

 

Why the burnt fuel relay?

Burnt fuel pump relay - Turbobricks Forums

Second fuel pump relay - Turbobricks Forums

 

I'll try and respond to as much as I can right now. It's raining and I don't feel like heading outside today.

-I've saved all of the Greenbooks, but thanks for the reminder. They're always helpful.

-The plugs are not wet, but that makes sense because the pumps aren't running unless I'm running them manually. It doesn't appear that the injection is kicking in.

-I'll check the resistance, but how do I check for voltage? Unfortunately I don't have an assistant, so hopefully I don't need to turn the key and test something.

-The camshaft is turning, no problem with the belt.

-No RPM gauge.

-I don't understand what you mean by "Why the burnt relay?" It wasn't a burnt prong, but a burnt spot on the board inside. Also, the relay was 25 years old and it looks like the burn was no recent. I don't see any damaged wiring. I'd be more skeptical of the relay and wiring if there weren't other electrical systems no kicking in.

Thanks for all of the help so far!