turbokinetic
Registered User
Hey folks. I am working on a 1985 Oldsmobile diesel engine. It has the DB2 pump which is so well supported here on the forum.
I'm working on a friend's car which has been stored at my location for about 2 years. I have been driving the car every couple of months, about 20 - 30 miles each startup; and until now it has run very well.
The car was sent here nonrunning. The previous owner damaged the engine by overheating, and then changed the IP as a troubleshooting step. Therefore, the IP appears relatively new.
The car has been starting up instantly and running like new until the last 2 times I ran it. The first indication of any problem was the "stall upon returning to idle" issue which is commonly the metering valve getting sticky. Initially, this only occurred when the engine was fully warmed up and the A/C was off.
It rapidly progressed to doing it no matter what, so that I had to be ready to two-foot drive it to keep the engine running.
Last drive of the car, it was a little slow to ignite when started. Maybe 5 seconds of cranking before it ignited. After the 20 minute drive, it was running OK but still had the return-to-idle stall. I planned to use transmission oil in the filter, but work called me out.
I went overseas for work and returned after about 2 months. The engine would not fire. I verified the ETR coil was good, and receiving power. The coil clicks audibly when powered on.
Next, I took the top cover of the IP off, and found that the metering valve was, indeed, stuck. The housing was full of clean fuel, but the valve took considerable effort by hand to move it. There was no roughness, merely a gummed or stiff sensation.
I removed the spin-on fuel filter and poured out the fuel. It was clean and free of water. I then refilled the filter with new Dexron transmission oil, and refitted it. Cranked the engine over until I could see the red color at the fuel return fitting of the pump. There is a solid stream of fuel from the return while cranking the engine over. Still no fuel delivery to the injectors.
I then removed the pump cover a second time, and moved the metering valve by hand again. It became perfectly free after about 2 manual cycles.
Again, I reassembled the pump and tried to start the engine. There was no ignition. I have loosened the injector lines on the front 3 cylinders, and there's no fuel coming out when the starter turns the engine. This is with the throttle at maximum, and while visually verifying a stream of fuel from the return.
I don't believe the pump has seized because the transfer pump passes fuel when the engine turns over. The electric lift pump is working. There is a constant dribble of fuel while the key is ON, from the return line; which increases to a stream when the engine is cranking over.
Any suggestions? I wonder if there is something else stuck inside the injection pump. I work on modern engines for my job, so diesels are not new to me. Just this early style pump is unfamiliar. Thanks again for any ideas.
Sincerely,
David
I'm working on a friend's car which has been stored at my location for about 2 years. I have been driving the car every couple of months, about 20 - 30 miles each startup; and until now it has run very well.
The car was sent here nonrunning. The previous owner damaged the engine by overheating, and then changed the IP as a troubleshooting step. Therefore, the IP appears relatively new.
The car has been starting up instantly and running like new until the last 2 times I ran it. The first indication of any problem was the "stall upon returning to idle" issue which is commonly the metering valve getting sticky. Initially, this only occurred when the engine was fully warmed up and the A/C was off.
It rapidly progressed to doing it no matter what, so that I had to be ready to two-foot drive it to keep the engine running.
Last drive of the car, it was a little slow to ignite when started. Maybe 5 seconds of cranking before it ignited. After the 20 minute drive, it was running OK but still had the return-to-idle stall. I planned to use transmission oil in the filter, but work called me out.
I went overseas for work and returned after about 2 months. The engine would not fire. I verified the ETR coil was good, and receiving power. The coil clicks audibly when powered on.
Next, I took the top cover of the IP off, and found that the metering valve was, indeed, stuck. The housing was full of clean fuel, but the valve took considerable effort by hand to move it. There was no roughness, merely a gummed or stiff sensation.
I removed the spin-on fuel filter and poured out the fuel. It was clean and free of water. I then refilled the filter with new Dexron transmission oil, and refitted it. Cranked the engine over until I could see the red color at the fuel return fitting of the pump. There is a solid stream of fuel from the return while cranking the engine over. Still no fuel delivery to the injectors.
I then removed the pump cover a second time, and moved the metering valve by hand again. It became perfectly free after about 2 manual cycles.
Again, I reassembled the pump and tried to start the engine. There was no ignition. I have loosened the injector lines on the front 3 cylinders, and there's no fuel coming out when the starter turns the engine. This is with the throttle at maximum, and while visually verifying a stream of fuel from the return.
I don't believe the pump has seized because the transfer pump passes fuel when the engine turns over. The electric lift pump is working. There is a constant dribble of fuel while the key is ON, from the return line; which increases to a stream when the engine is cranking over.
Any suggestions? I wonder if there is something else stuck inside the injection pump. I work on modern engines for my job, so diesels are not new to me. Just this early style pump is unfamiliar. Thanks again for any ideas.
Sincerely,
David
