Monday, August 07, 2006

Pump Timing Values & Return Lines

It turns out that I mistakedly set my pump timing to 0.44mm instead of the 0.75mm specified by Volvo for engines with an EGR system. This caused a bit of hard starting/rough running cold. The also increased cranking time when warm. I used to be able to just blip the key and she'd start. At 0.44mm, it would take a bit longer. there have been lots of numbers thrown around as to what the pump should be set to, anywhere from 0.72m to 0.95mm. Which one should you use??? According to Volvo Supplement to Manual 30571/1, the pump should be set to 0.75mm for all cars equipped with an EGR system. Unfortunately my car might be missing some of the EGR system (??) so I'm not sure if I should still use this value... Manual 30571/1 gives the following values:

D24T Exc. USA/Canada 0.9mm
D24T USA/Canada '82-'83 0.8mm
D24T USA Federal/Canada '84- 0.85mm
D24T USA Calif. '84 0.75mm

If it wasn't such a pain to retime the pump, I would try a spread of values and post some feedback :/ BUT, I found this on a Dodge Ram website

Advancing the timing will...
  • Decrease exhaust temperature
  • Increase cylinder temperatures/pressures
  • Increase fuel economy
  • Increase your output of NOx
  • Decrease your output of Hydrocarbons
  • Increase the amount of black smoke at peak torque

FYI, the cold start device, when operating correctly, should increase the above measurements by 0.20-0.25mm. This gives you a quantitative test for you cold start mechanism.

I have started selling 1/8" I.D. X 1/4" O.D. biodiesel-compatible fuel line. It's more heat resistant than Tygon and has the perfect degree of flexibility. The plastic hose I put on after the pump rebuild cracked and dumped fuel down the side of the engine so polyethylene(translucent plastic) fuel line is definitely not a good idea for this application. At $3 a foot, it's 1/2 the cost of Viton and it comes in a cool translucent bright yellow color. You may send $$ for as many feet as you'd like + $4.05 USPS Priority shipping to via Paypal or email me for my home address to mail me a personal check.


Anonymous Anonymous said...

I just want to say that your blog is very informative and I'm checking in every week.


4:31 PM  
Blogger Unknown said...

I just found you via Dogpile search engine and can't stop reading. Especially since I just aquired my first D24T which happens to be in an '84 Volvo 240. My regular ride is an '03 Golf TDI. I just finished replacing the injector pump with a Volvo remanufactured I scored on Ebay and the car runs pretty well. After reading some of your experiences about timing, I should probably get a better dial indicator set-up on mine and possibly advance it a bit. The car wasn't running when I bought it a couple months ago. She's much happier now. Thanks. Bard

10:24 PM  
Blogger smokeybrick said...

bard, I'm in the process of putting a d24t in my 240 wagon. How is your turbo oil return line routed? The d24t oil pan will not fit in a 240 so I'm gonna use the d24 non turbo pan but I'm not sure where the best place is to drill for a return line on the pan

4:29 AM  
Blogger magi said...

Thank you for the info. It sounds pretty user friendly. I guess I’ll pick one up for fun. thank u Volvo Exhausts

8:37 PM  

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