Timing for high altitude

[MattRabbit]

Hi people,

My '81 NA Rabbit has absolutely no power.   It's hard to get it up to 65mph on a good day.  It'll do 75 downhill with a tailwind (literally), but I keep seeing others on the forums who have a lot more power than I do.

I'm wondering if I may have the timing set incorrectly.  I set it at 1.00mm when I had it rebuilt, and it starts/runs perfectly.  It's a little noisier than others I've heard, but nothing too bad.  The injectors could probably be replaced as well, but I'm a little short of cash at the moment, so that's probably not something I'll do for awhile.

Are you supposed to time these pumps differently if you live at high altitude?  I live at 5000 feet, so that might have a lot to do with things.  Short of adding a turbo, what else can I do?

Thanks!

[tylernt]

Do you get a lot of black smoke when you put the pedal to the metal? If not, you need to turn up the smoke screw. That should help a lot.  

Also, the ram-air intake mod is cheap and should give you a few highway HP. http://www.4crawler.com/Diesel/CheapTricks/index.shtml#ColdAirIntake

[greggearhead]

Altitude kills NA diesels.  I can't say what the best timing is for altitude, but I would look into doing a few other bolt ons to up the power a bit (header, exhaust, etc).

[MattRabbit]

was getting a lot of black smoke on WOT, so I turned the smoke screw down 1/8 of a turn.  This didn't affect power at all, but pretty much killed the smoking.

Hey Greg!  The Strut housings are still working fine.  They're on this car right now.  

I also have a 5-speed that I'm about to put in it.  It's an FN, but it should be a bit better than the wide ratio 4-speed that's in it now.  We'll see how it does.

[MattRabbit]

Valve lash? Air filter? Dragging brakes? Front end alignment? Tire pressure?

Valve Lash - nope, not yet.
Air Filter - check!
Dragging brakes - just changed all brakes and related parts
Front end alignment - check!
tire pressure - using 155/13's right now at around 34 psi

This car has really never had power.  I used to really have to use momentum when I lived in the mountains in order to be able to make it up the hills without dogging too bad.  My parents had an '82 diesel with a 5-speed that felt like it had twice the power of my '81.  I think the PO of the '82 had cranked up the fuel delivery, since it smoked a lot more.

I'll put in the 5-speed and my 14" wheels/tires (for stability. ) and see if that makes a difference.

[greggearhead]

The 5 spd will really make a difference, even the wide ratio box.  

Glad the housings are working for you.

[MattRabbit]

I think the compression is ok, as I did a ring job about 80K miles ago.  It still regularly gets 50mpg, and starts in any weather.

The injectors might be original.  They were next on the list of things to replace.  We've had the car since it was new, and I don't remember my father ever replacing them at any point.  I know that I didn't.

Is there any way to replace the nozzles without costing an arm/leg/firstborn child?  I noticed that rebuilding injectors costs about $40 apiece, and I'm not that rich currently.

[tylernt]

Is there any way to replace the nozzles without costing an arm/leg/firstborn child?  I noticed that rebuilding injectors costs about $40 apiece, and I'm not that rich currently.

Well you need a pop tester, but you can build one yourself out of a $20 hydraulic jack and a pressure gauge if you're handy (and if you've done a ring job you probably are). Nozzles by themselves are $20/ea.

I think you also need different thicknesses of shims to adjust breaking pressure? If so, no idea where you could get those.

[tylernt]

Autohausaz.com has n/a nozzles for less than $9 a piece.

Dang wish I'd have known that before I had mine rebuilt. Thanks for the tip, even if it is a bit late for me.