Little or NO power after bottoming out suspension- 1981 300SD
 

My friend was driving his SD on a dirt road and hit a dip, bottoming out the suspension and denting the oil pan.
About a mile later, the car died.

He tried putting on new filters, but still could not get the car to start.
He got it towed home and called me.

I replaced the dented oil pan.
I also replaced the old style (leaking) primer pump thinking that is the reason it would not start.

After about an hour trying to start it, I suspected something was wrong with the injection pump.
I decided to pull the IP and replace it with a known good one.

After trying to get the start of delivery set (removing/replacing the IP three times), I figured something was wrong with the timing device, or something else.
I decided to just put the original pump back on.
After successfully getting SOD set, the engine finally started, however, it barely had any power, and it would only rev up to maybe 1,500 RPM.

I don't want to pull the IP again.
I thought that maybe the muffler was clogged, so I pulled the downpipe off the turbo, and still no power.
It seems to idle perfectly, but barely has enough power to move the car in gear (I can walk faster).

I also found out that the turbo was worn out, and thought that it might be bad enough to keep the engine from getting any air.
I removed both manifolds and the turbo, and started the engine to see if the turbo was restricting the air (had it bolted to the oil feed tube and drain tube to prevent an oil spill), but still no power.

Having ruled out he entire exhaust system, the only thing left is the fuel system.
The filters are both new, and the primer pump is new (new style).
I even tried pumping the primer while it was running to help pump fuel, but still no change.
I also tried clamping the return hose, but that did not change anything either.

Anyone have any ideas?
Like I said, I really don't want to pull the IP again.

There is the possibility that something broke inside the IP from the suspension bottoming out, but I would like to rule everything else out before trying another IP (for the second time).
I already have over 8 hours invested in trying to repair my friends car (his only transportation), and don't want to needlessly invest any more.

Thanks in advance for any ideas or help...Rich

did the timing chain maybe jump a tooth? would the engine self destruct if that happened though? if it idles, but no rev, it makes me think timing, but i'm sure someone with way more knowledge will chime in.

Try running it off a small canister: just pull the feed and return lines, and stick them in there; make sure the canister is secured properly and no diesel can spill out, and take it for a very short test drive.

When the steel fuel lines are 30 years old, they might be clogged from rust knocked loose during the impact. When I started my 200D after 12 years of sitting it barely started; when I ran it off a canister, it started much easier and seemed to rev better, so that could be your problem too.

Are the throttle linkages moving normally (when you put the pedal down, is the movement reaching the IP)?

Did the dip hit the underside of the middle of the car? The metal fuel lines (and brake line) run along under the body and may have been flattened like the oil pan, preventing any fuel flow.

My first thought when I read he bottomed out and dented the pan, was oil pump damage, and oil starvation.

Charlie

+1

I agree with this as a first step. The symptoms sound like fuel. Running off of a bottle (like doing a diesel purge) would take the tank, strainer, fuel lines etc out of the eqution very simply.

Thank you all for the quick replies. I will definitely try running it on a can of Diesel Purge first (I have one in stock). I had not thought of the fuel lines, but I will check them. I also thought of oil starvation to the pump as well. However, I would think the engine would have made some noise from oil starvation long before the IP could get damaged from same. One of the first things I checked was the timing. I pulled the cover to verify the mark on the cam tower and the crank. They both align perfectly. The car was needing a new vac pump anyway, so I checked the IP timer while the pump was out. It seemed to work as intended (turning it against the spring pressure). I also pulled the line to the shutoff, thinking I might have a small amount of vac leaking past the valve on the ign sw. That did not make it run any better. Even though I crimped the return line, could the pressure relief valve cause this condition? I might bring along a known good one and replace it just for grins anyway. Keep the suggestions coming. Thanks, Rich

You said the filters are new, but I wonder if it would be worth putting on fresh ones, just to be sure. I'm a firm believer in taking the simplest things out of the equation before getting into the more complex and costly ones.

The new filters were put on after the car died, and before towing it home. With removing and replacing the IP more than once and using the new primer pump, I am sure the filters are full. However, that is with the tank and fuel lines feeding the system. Diesel Purge as the fuel supply should rule out the filters as well (return flow should be visible).

+2 either pushed up the intake against the bottom of the pan and starved it that way or cracked the oil pump housing killing all pump action.:eek:

(siezed bearings)

The oil pump is fine, the dent just crushed the rubber piece on the bottom. It definitely still has oil pressure.

UPDATE:
 

We ran the engine on a separate can of fuel to rule out the tank and fuel lines. It runs the same- only can get about 1,500 to 1,800 RPM out of it. I figured that the only thing that is left is the IP. The other day we went to a wreckin' yard and got a used IP from an SD. Yesterday I replaced the IP with the used one. The engine runs exactly the same. It was a lot of work, but at least the IP is ruled out. Again, the main fuel filter was replaced with a new one right after the problem started. It has a new style primer pump. I am at a loss as to what the problem might be. The turbo was rebuilt while all this was going on for the last 2 weeks, so it is ruled out as well. Anyone with any ideas?

When the engine was ran on the can of fuel (actually a clear bottle), the fuel flow was evident (pulsing of lift pump). Also, the flow from the drip tube while adjusting the start of delivery showed that it was getting plenty of fuel. The engine idles perfectly, and does not miss at all. When the throttle is wide open, it is very smooth, but only revs up to about a steady 1,800 RPM.