internal injection pump pressure
Moderator: Fatmobile
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- Cetane Booster
- Posts: 36
- Joined: Fri Nov 09, 2007 11:52 pm
I am talking about the replacing the internal transfer pump, not adding a lift pump. The inlet pressure is pretty much constant without a lift pump isn't it? The only ways I can see to increase the internal IP pressure would be 1) increase fuel viscosity 2) decrease the size of the outlet orifice 3) increase the efficiency of the internal transfer pump (by getting new vanes/stator/etc.) 4) adjust the internal pressure regulator thingamabob.
I guess my question is: what is the main cause of low internal IP pressure?
I guess my question is: what is the main cause of low internal IP pressure?
I think if it's pressure you want, then adjusting the thingamabob with a punch and hammer while a pressure gauge and tachometer are attached is the way to go; it's quick and simple. I've seen several old pumps that could easily be adjusted to specs for pressure so long as the vanes aren't stuck. You should probably also check flow rate while you're at it; specs given previously in this thread.
81 Pickup 1.6NA; '86 Cabriolet with 1.6 TD
After setting to 43.5 at 500 pump rpm, per spec, my initial results are 47mpg highway/city mix (90%/10% respectively) A huge improvement over the 38 I was getting. Anyone have any other ideas to increase economy some? I have the dreaded AWY so this has some play, and I do have 35psi in all four tires, free rolling wheels, no brakes sticking on.
Just for anybody else with an interest in fuel economy who might be following this topic, I thought I would confirm that my results were similar to Coke's. I got about a 19% improvement in mileage simply by adjusting the internal pump pressure.
The equipment to check it only costs about $50; it will pay for itself many times over if the little diesel is your daily driver.
The equipment to check it only costs about $50; it will pay for itself many times over if the little diesel is your daily driver.
81 Pickup 1.6NA; '86 Cabriolet with 1.6 TD
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- Cetane Booster
- Posts: 36
- Joined: Fri Nov 09, 2007 11:52 pm
I know tawney had a pile of scrap pumps he was spinning with a drill. We dont use a pop tester, we use a pressure gauge hooked somehow to the return fitting on the pump to get a pressure reading from inside the pump. This way, we can adjust the pressure while watching it on a gauge, and then verify that at 1000 pump RPM, we have the desired reading as well.
It can be installed as a permanent fixture if desired.
It can be installed as a permanent fixture if desired.