W115 1976 240D chugging for gas after purge.

[marco5]

I've done many diesel purges before, I'm not sure why its chugging and stalling for gas.

I've bleed it as required in the mercedes manual... I'm not sure what to do. Could I of possibly blown the injector pump? I doubt that but who knows. I wonder if there is possibly still air in the system?

Please help!!

Heres a videw of how it runs, the sound is messed up so turn your speakers a bit louder. YouTube - VID 20110503 00017

[Diesel911]

Air Leak?

This is where it would be nice if there was a Fuel Supply Pressure Gauge on these vehicles. It could be an issue with the Pressure Relief/Overflow Valve on the Rear of the IP or maybe something is holding one of the Fuel Supply/Lift Pump valves open.

You might try pumping on the Hand Primer while the Engine is running and see if while you are pumping things improve. If things improve you have some sort of Fuel Supply issue.

If the Purge is done by recirculating the Purge Fluid. Maybe the Secondary Spin-on Filter is plugged by the stuff that was purged out of the IP housing?

If you do the Injector Cut Out Test and see if it is a specific Cylinder having the issue.
Then swap the Injector from the bad Cylinder with one of the ones from a good Cylinder and see if the problem follows the Injector from the suspect Cylinder.
If it follows the Injector it may be something had gotten inside of the Injector.

[katja]

Did you get all the fittings tight when you put the lines back on? I would guess an air leak or newly-formed crack at the prefilter since you disconnect there to do the purge.
I once had a fuel leak there near the clamp and didn't notice any fuel leaking there, but it sure let air in, stopping the engine. Or as Diesel911 said, the main filter is clogged. You could let some fuel out at the nut near the bottom of the filter can to check what comes out (see if it's watery or dirty).

Couldn't hear much on the video except what sounds like a very bad exhaust leak (or do you even have the entire exhaust system on?)

[Kpmurphy]

If you have been pumping the hell out of the hand primer pump it may have an air leak.
all my cars i have the newer style primer pump. This may not be your problem i thought i would say something because i had a similer problem.

it defentley sems like you are only runing on a couple cilenders.

crack each injector line if the idel changes move on intill nothing changed there you should start looking for the issue.

[Diesel911]

Originally Posted by katja

Did you get all the fittings tight when you put the lines back on? I would guess an air leak or newly-formed crack at the prefilter since you disconnect there to do the purge.
I once had a fuel leak there near the clamp and didn't notice any fuel leaking there, but it sure let air in, stopping the engine. Or as Diesel911 said, the main filter is clogged. You could let some fuel out at the nut near the bottom of the filter can to check what comes out (see if it's watery or dirty).

Couldn't hear much on the video except what sounds like a very bad exhaust leak (or do you even have the entire exhaust system on?)

I did not notice his Year. If he has the Cartridge type Fuel Filter he could pull the Cartridge out and take a look at it. But, still better to change it to be sure that at least that part of the system is OK.

[79Mercy]

I don't think it would make a difference but i think you have the clear filter installed backwards. How did it run before you did the purge?

[marco5]

Ok I got her fixed. These are the steps I followed:

1) I filled in the main fuel canaster with diesel to the top
2) I syphoned the fuel line going to this canaster
3) I retightened this canster and then focused on the small clear filter
4) I syphoned the fuel line going to the small clear filter and attached it very tightly
5) I quickly manual primed the Injector Pump until I saw fuel coming into the clear filter
6) I untightened the injector pump bleed screw and primed until I saw fuel and tigtened it back up
7) I started the car and it ran like crap, while it was running I hand primed the injector pump a few more times and it ran like NEW.

I think these steps to insure that there is NO air stuck in the IP or the fuel system. Since I've done this I've had NO issues...

I also just found a AC system in my 76.. I'm not even gonna try messing with that LOL

[Kpmurphy]

good job