Fixing the Lethargy
 

Hey guys,

My 300 turbo diesel has been lethargic for awhile now. About six months ago I did a lot of things at once: converted to waste veg, installed a boost guage, replaced the head gasket, and adjusted the tranny and bowden cable.

The car has the follow syptoms:

- Can barely move when cold
- Will ocassionally lug out and die when just started cold, requiring pedal to the floor for a minute or two for the revs to creep up and the pedal to become responsive.
- Cannot pull past 75 on the freeway
- When kicking down on the freeway to get into the power range (~4000RPM), the car has NO MORE POWER. It seems to make just as much or more power at 3000RPM than anywhere else. It is bizzare to hit the kickdown switch and LOSE speed going up a hill.
- Slow starts even when hot
- 0-60 in about 16-17 seconds

Here are the tests I have done:

Boost guage indicated 8 psi at WOT 4300RPM. I adjusted the turbo wastegate (AiReasearch) by 3.5 turns... hoping to gain 3.5PSI. Unfortunantly, it only kicked up to 10.

I have removed the EGR and fashioned two mighty fine block off plates. I don't think either the intake or exhaust block off could possibly be leaking.

I unscrewed the ALDA by two turns, which brought it all the way out (PO must have adjusted it at some point).

New air filter.

All the turbo boost lines are clean and straight. I haven't removed the banjo bolt to make sure the fittings are clean though.

I think I have pretty much determined this is a fuel problem. The fact that I pull 10PSI of boost means I have plenty of air, even if their might be a little leak somewhere.

I am guessing that the IP timing is off because my old crappy mechanic timed it wrong while putting the head back on. I guess I should put in new fuel filters though just to be sure. My other guess would be that the valve/regulator thing between the turbo and ALDA could be causing problems.

Thoughts? Where should I look next?


Cassidy

Cazzzidy, good to see you again.
I don't know squat about turbos, cause I have never had one.
But if that was my car, the first thing I would do is put the fuel system back to stock, change all filters -pull the tank strainer and clean, put fresh diesel in there, and see how she runs. Make sure it isn't the conversion. Then I would consider an injector swap, if you can get a loaner set.

Get rid of a crappy mechanic that sets the timing wrong! That might just be the problem as just being off 3 or 4 degrees on timing can make a big difference. Its easy to check with drip tube.
Bypass the valve thing for a test by running a rubber line directly to the ALDA from the intake manifold banjobolt. If you need one I can supply the right one with pipe nipples. cheap.

Injectors are next, if plugged by dirty WVO stuff then its obvious what you need in the way of fuel delivery and I hope the IP isn't involved.
Drive that thing over the hill to the Bay Area and find a decent shop. I know several. Please don't ask me to help I am up to my eyeballs with job and travel.

run some diesel purge, change your fuel filters and go back to dino diesel for a couple of tanks. Sounds like a fuel problem to me too. I had one instance this past winter on the way to work where when I accelerated onto the highway everything was fine, but when it reached 70-75 mph it would go no faster. When I got to work, I opened the hood and looked at the fuel prefilter. It was all cloudy, and you could see that the fuel was thick by the way it clumped around the bubbles. It was -2F, about as cold as it ever got here last winter and hasn't happened since.

The line from the intake manifold to the switchover valve tends to get clogged. Remove the line at the manifold and clean the hollow bolt and banjo fitting. (Do not emove the banjo fitting from the line.) Also check that line, and the line from the valve to the IP, for leaks.

This is consistent with injector/IP/Timing issues (Don't know Squat about ALDA - No Turbos in Australian delivered 300Ds.) poor idle fuel delivery? Typical of fuel starvation This is consistent with injector/IP/Timing issues. Should be plenty, but remember the boost doesn't cut in until you hit 1000+ RPM This is for Off-Road use only - Right? Shouldn't be the problem if you can get 10 psi boost. This would affect fuelling under boost, but not a idle or <1000 RPM. I agree Start with the fuel filters.How is your WVO system configured? 2 Tank? If so, are the issues the same on diesel and on WVO? Are any filters common between these fuels?

If replacing the fuel filters doesn't make a MAJOR improvement, pull and clean the injectors, set the injection timing, reinstall injectors and try it out.

Have Fun
Tony