Loss of power 87 300td wagon
 

Hey, I filled my tank the other day and when I hit the highway I was not getting any power out of the car. I am going to check the fuel filters but would like to know if it is an easy task to check the screen in the fuel tank. I replaced the fuel filters not too long ago and I ran two "Diesel purge" cans about a month ago(the purge turned black for both cans, like really black). Car has 360km. If it is cold out, well below freezing, it loves to smoke when I start it as well.

Any advice for after I check the fuel filters would be great!

Is there a clear signal line from the intake manifold through the overboost switchover valve to the ALDA?

Updating to an afterglow relay or cutting the purple wire to the glow relay should help cold starts.

Sixto
83 300SD
98 E320 wagon

+1 on the alda sense line. It's always the first thing I check with a turbo car. Look on the left side of the intake manifold...find the big sensor (that's the overload sensor) and directly beneath the sensor, there will be a hose going into a fitting. Remove the hose, then undo the fitting. I'll be it's clogged.

I may be wrong, but I think this car already has an afterglow relay.

This might be a long shot but I noticed that you stated it happened after you filled up...... I've had that exact experience and found that the gas station (which I never used before) had leaking fuel storage tanks under the ground and algae had grown in the stored diesel and ultimately contaminated and clogged mt system.

I replaced the fuel filter and replaced the inline (see through) filter 3 times, at which point the power restored.

I was taught to never purchase diesel fuel from older gas stations and to look for cracks in the concrete where the tanks are located...... I live by this rule!

Hope this helps.

X 2 on bad fuel.

I was running low on fuel years ago, only put in two gallons from an old urban station in Hayward just to make it home.
The car ran rough and could barely make it over the San Mateo-Hayward bridge.
A fillup from the local Valero station cured it's ills.

There may be an excessive amount of water, sediment and bio-contaminants in the fuel if it came from the bottom of the station's tank.
To test for water, drain about a pint of fuel from the line coming off the fuel tank into a clear container, and see if there is visible water in the fuel.
Use straight jawed visegrips and a rag as your fuel clamp if you don't have one.

If there is a lot of water , you may need to drain the tank.
If not, to remediate the fuel, add StarTron fuel tank cleaner (availble from your marine supply house).
Change or rinse out the primary fuel filter as needed until you burn up the bad fuel.

I always carry a spare primary and seconday fuel filter, tools to change the filters, a mini-tank (a Gatorade quart bottle with two holes in the cap and two short lengths of fuel hose), and ATF to use as emergency fuel.

x3 on bad fuel.

I've quickly learned that diesel fuel around my area is HIGHLY variable, even from the same station! I knew gasoline quality sucked out loud, but it has nothing on diesel!

I luckily haven't had fuel bad enough to clog my filters or contaminate the tank with bio crap, but I've gotten fuel with very poor cetane numbers. Car starts rough, idles fairly rough, is LOUD (sounds like a Cummins), and is noticeably down on power. I currently have a crap tank of fuel in it right now, some white-bottle Power Services helps a bit, but isn't a full cure.

The Idle is not that bad it is only when I get up to speed and then stomp on the gas. The engine reves up but there is no get up and go in the car. I am going to talk to the gas station owner and when it warms up a bit I will check the line for the ALDA.

Thanks for the help.

If the engine is revving when you step on the gas, but there's no change in speed in the car, I'd be inclined to think there's a problem with your transmission...

I know this is a little late but I finally got around to testing the ALDA lines. They are clear from the Y30 for sure. I also removed the ALDA and found that the o-ring inside was worn out, I hope to have a new one soon(not 100% sure where to get it or the size).

I also replaced all the fuel filters and as well as the fuel tank screen(it was surprisingly clean). This didn't change anything.

I blocked the EGR vacuum line. The inside of the intake manifold is extremely dirty. I am going to try to clean it in the next two weeks. How would I clean the openings in the head once the manifold is removed? I can't really spray oven cleaner in there or light it on fire...

Any other tests I should try?

Thanks for the help

A popsicle stick works well to scoop the crap out of the intake runners in the head. It isn't very deep, so you can get in there and get a lot out pretty easily. My SDL's intake manifold was a nightmare. It was so choked down that it had maybe 1.5cm holes it was breathing through. It was a mess to clean up, I soaked mine in a big tub with some "Oil Eater" brand degreaser for about a week and it all just washed out. EGR is now blocked off permanently...

This is in general.

Loss of Power causes and trouble shooting
Starting with the most frequent cause/s remember there can be more then one cause.
Fuel Filters restricted- Change Fuel Filters.

Fuel Tank Screen- Remove and clean Screen or replace it.

One way to trouble shoot. Swap the positions of the Fuel Return hose with the fuel inlet hose and be sure you have 1/2 Tank of Fuel. That reverses the flow in the hoses and does not pull fuel through the tank screen but from a higher position in the Tank (which also means you would run out of fuel before the gauge shows that). If you power is restored when you do that your Tank Screen is restricted.

Plugged or restricted Fuel Tank Vent. Mud and road gunk can plug the outlet. On a WQ123 it is in front of the left rear fender.
One way to troubleshoot- Have about 1/2 tank of fuel (you don't want a full tank) and drive without the Fuel Fill Cap. Having no cap acts as the tank vent. If it drives normally with the Cap off your vent is likely plugged up.

Fuel Pressure Relief/Overflow Valve- If it is the type that can be dissembled the spring in it can be stretched back to 27mm of free length. Otherwise it needs to be replaced

Fuel Supply/Lift Pump- The Valves inside can get gunked up and the Piston can stick. There is rebuild kits for it or you can take it apart and clean it out.

Throttle linkages from the Pedal to the Fuel Injection Pump out of adjustment or parts worn or broken.

Plugged Air Filter or air inlet system.

Startron for diesels as has an enzyme that eats up stuff that grows in diesel fuel and breaks them up into small enough pieces they pass thorugh the Fuel Filters.

Another update.

Ok it was the ALDA, I do not have it installed right now and the power is back and it feels great! I am going to install it again in the next couple of days because one of the members sent me a replacement o-ring. I have one left if anyone needs one.

Thanks for the help.

Maybe this is for a new thread but, I was wondering if there is a way to install a K&N air filter. The current air filter is hard to find so I was thinking of modifying the air intake... Any thoughts or photos

I generally don't like K&N's. Not just on diesels, they're generally ineffective and overhyped. Mail order places have a choice of brands for your filter.