no start
 

seems like we got fuel coming in to injector pump, but no fuel going into the injectors, as seen by loosining the injector nuts no fuel coming out when we turn key . cleaned it up and does run on carb cleaner. any ideas 1989 260e 4 door auto.

If you have a check valve in your return line Id sure be pinching off your return line and trying to see if it runs then.

I bought a Volvo yrs ago that the owner had put $600/700 of OEM parts under the hood to get it to start. The fault was a bad check valve that a quarter at a local junk yard solved.

The check valve was releasing pressure almost immediately and the system would never rise to the required starting pressure

My 1988 560 did this same thing on Sunday.
No start, dry plugs, jumped the fuel pump, pumps were running and depressed the airflow plate- Nothin. No singing injectors, no nothing.

I had to go get all my tools and fuel gauges, hooked up the fuel gauges, jumped the pumps again and found the fuel pressure was correct. At that point I deflected the airflow plate and Voila. Singing injectors.

Disconnected everything, put the air cleaner back on, closed the hood, jumped in and it started right up. (was this some kind of automotive test of will??).

Why the injectors didn't flow with the pumps on and airflow plate depressed is a good question.

Can an EHA "stick" closed and bypass all the fuel pressure causing our no-starts?