Author Topic: mpg (Read 13089 times)

jtanguay · « **Reply #30 on:** July 17, 2005, 09:04:24 am »

Power when cold.. but less power when warm... sounds to me like my old car. I think it was either the injection pump, or the cold air filter I threw in (heatsoak)

btw yes the compression is 23:1 so that means if you're boosting 10 psi then magnify that by 23... so that is an added 230 psi once fully compressed. Obviously that is a heck of a lot of pressure and some of it is going to escape somehow. I'd say get a metal head gasket and that might help?

ejust · « **Reply #31 on:** July 17, 2005, 09:53:21 am »

ive got the stock snorkel and air filter on mine so heat shouldnt be problem as far is air intake.

jtanguay · « **Reply #32 on:** July 17, 2005, 05:49:53 pm »

I would definitely consider an injection pump rebuild then, or injector rebuild.

chrissev · « **Reply #33 on:** July 17, 2005, 10:59:07 pm »

Quote

Question..would a govenor mod kill milage??

I don't think so. The governor just kills the fuel supply above 4000rpm. Most likely you never run your car above that anyway. People just do that modification if they want to race their cars and they need to run the engine at max power output.

Adjustments to the fuel supply can kill mileage though. If you adjust it and get a lot of smoke, then that is your fuel going out the back of your car.

Temperature definately kills power output on those cars. Hot air has less density than cold air does, so less air molecules get into the cylinders when the air is hot. The turbo is right next to the exhaust so the air can get pretty hot. This is why intercooling the intake air is such an improvement on these cars.

ejust · « **Reply #34 on:** July 22, 2005, 11:45:06 am »

well, i did govenor mod. Actually had the guts to do it. Damn throttle springs are a pain to get back on, but i figured it out. Definitely zippier. i can see between the gov mod, more fuel, more boost, and intercooling why you racers have fast cars.

heres what ive come up with...

the mod increases fueling/pressure which increases the smoke out the tail pipe

I tried to back off fueling to not have a cloud. But my idle is low and the adjustment is all the way up. I can turn the fuel back up, be able to raise idle to normal, but then i mosquito fog and watch my mpg drop. I did the mod to have a tad more zip around town. Maybe a partial mod would be better. i dont know.
My milage is still low by Bentley standards. All city driving - 33mpg (14km/L), 50/50 - 37-38(16km/L), all hwy - 42mpg (18km/L)was the best ive ever had at 65mph (105kmh) steady.
I really hope to get an intercooler maybe that would help. Im sure my injectors need rebuilding. Who does that sort of work for a really good price? Im sure i can replace the nozzles myself, but the pressures will need adjusting.

ejust · « **Reply #35 on:** August 01, 2005, 04:39:09 pm »

cant get the idle to stablize now. if i dont had the residule adjustment up, i wont stay running, but now the idle is like 1200. The actual idle adjustment isnt enuf. I think im gonna go back to the normal stock setting (if i can find them again).

I think an injectior is going personally. Doesnt seems to have the power it used to at all. Fairly doggy. Plus the oil in the coolant scares me. MPG still averaging around 38mpg (US). Oil pressure at idle - 10-12psi (vavle lifters ticking hard) Sigh.........

After all the work last fall on the suspension, guess now i gotta stick a ton more money into this car for the enigne/fuel. Getting about ready to sell this darn thing! Engine rebuilds arent cheap!

insdtanoodles · « **Reply #36 on:** August 04, 2005, 07:39:57 pm »

I got a few questions about my car as well. I just got a 1996 vw jetta with a 1.9TD and I am wondering what would cause my poor mileage which is around 7-8L per 100km, the car has 196000km on it. I know right now that the alignment is off and that when my dad put on the timing belt that the injector pump was "close enough" which means it is out of timing by 1 tooth. I am thinking of getting back in there are timing it properly, would the pump being out of time effect mileage much? I am also wondering how much of a different getting new injectors would make. There is also sideways play in the turbo spool and I know that if the turbo isnt working properly that your fuel mileage would go down, can you get rebuild kits for the turbo or do I have to get a new or remanufactured one?

Thanks

ejust · « **Reply #37 on:** August 10, 2005, 11:45:58 pm »

dieselweasel · « **Reply #38 on:** August 12, 2005, 06:18:23 pm »

Quote from: "insdtanoodles"

I would the pump being out of time effect mileage much?

There is also sideways play in the turbo spool
Thanks

Improper pump timing will definitely have negative effects on fuel economy. You want the pump to be timed to the more advanced side of spec for best mpg. Check pump timing before going any deeper.

Sideways, or radial play in a turbo is ok as long as the compressor wheel isn't hitting the housing. If there's axial or end to end play, the turbo should be replaced.

Ejust - You should remove the injectors and get them tested at a fuel injection shop. I got mine tested for free.

ejust · « **Reply #39 on:** August 12, 2005, 07:25:39 pm »

where y'all get 'em tested for free?? There aint no one within at least 150mi (240km) that would test them for free. The nearest place that can even test them at all is 60mi away and it would cost around $40US just to test it. No other work done.

fatmobile · « **Reply #40 on:** August 13, 2005, 12:14:16 am »

I get mine tested locally, for free too ... well I bring them baked goods, donuts and cookies.
They are going to test a set I dropped off last week and set them to the right pressure.
What is the suggested breaking pressure?
The '84 Bentley says 1706 - 1849 for the NA diesel and 2030 to 2200 psi for used turbodiesel injectors.
Anyone think different?
What happens if I set them for turbo diesel and use them in a vegy burning NA diesel?

ejust · « **Reply #41 on:** August 13, 2005, 10:37:29 am »

maybe i could send them to you and you could get them test and reset for me LOL Then ill change my head gasket at the same time

jtanguay · « **Reply #42 on:** August 13, 2005, 11:32:48 pm »

well fatmobile I think the veggie burning NA with some turbo injectors would run pretty good since the veggie oil is thicker

fatmobile · « **Reply #43 on:** August 14, 2005, 12:43:04 am »

I've heard bumping the pressure up helps with the spray pattern when running on vegy, not sure if they were doing this with special injector inserts or what effect it had on fuel mileage.
If no one on here knows for sure, off the top of their head, what a good vegy injector breaking pressure is, I'll have to do some searching. Maybe something less than the turbo diesel injectors.

Quote

maybe i could send them to you and you could get them test and reset for me LOL Then ill change my head gasket at the same time

Better send some dounuts too, ha.
I'm expecting to be charged for adjusting the breaking pressure, that could take some time. He checks for breaking pressure, spray pattern and drips etc. in about 5 minutes.

Patrick · « **Reply #44 on:** August 14, 2005, 06:00:22 am »

At that time of day(night?) on a weekend, wouldn't beer be a better motivator? :lol: