Author Topic: IP pressure Dynamic / static timing help please  (Read 3562 times)

October 19, 2009, 01:29:29 pm

MizpahPAH

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IP pressure Dynamic / static timing help please
« on: October 19, 2009, 01:29:29 pm »
When I bought this 86 N/A jetta the IP pressure was around 12 psi at Idle the timing was set at 1.06mm,

the injectors are poping at 1800 psi.

I have been running it with about 6oz of 2cyc oil and 6oz of cetane boost each tank.

I have not put it back to that since I started fiddleing with it, trying to get more performance and mileage.
When I set it to 30psi at 500rpm and timing at .90mm I get bad marbles at idle and midrange 43mpg us and white smoke / fog

I dropped the pressure to around 20 still has marbles not as bad still smokes and mpg is still around 43mpg,
and if I step into it it falls on its face.

I now have it set to 25psi and .85mm fair performance barely any marbles will fill up tommorow milage is looking a bit better but top of rpm has suffered
the advance cable doesnt change Idle anymore and can barely hear marbles

am I close in thinking the dynamic timing spring is weak

I bought a pezeo timing adapter and was thinking I would lower the pressure then slowly raise it while keeping an eye on timing to see when pressue
starts to overcome the spring.

does the pressue advance the timing at Idle?

I am going to get some readings and see how it runs at diffrent settings before pulling the spring cap and shims

any Ideas thoughts.

Thanks



Reply #1October 21, 2009, 12:22:45 am

MizpahPAH

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Re: IP pressure Dynamic / static timing help please
« Reply #1 on: October 21, 2009, 12:22:45 am »
Thank you Andrew!

Running at 85mm is a lot quieter I am going to try to lower it a bit more and bump the pressure up while watching the timing advance.

I guess its time to get a new good set of Injectors that pop within spec  ;D

Reply #2October 22, 2009, 10:16:57 pm

MizpahPAH

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Re: IP pressure Dynamic / static timing help please
« Reply #2 on: October 22, 2009, 10:16:57 pm »
I got a little time today to hook up the injection detector and timing light.

I cleaned off the injector line but its still a little eratic.

For a bit while it was stable I to 8 degrees before TDC at 950 rpm 25psi internal pressure.
Static timing at 85.

I still have mid range marbles or what sounds like marbles.

The oil pressure is still too high even with straight 30 weight oil
at Idle head and oil filter hot 20psi 5th gear 55mph pressure 60psi
I think I am going to put the old pump back in anything I should check before I do
I replaced it when I was in it replacing the IM shaft bearings I had pretty good pressure with the old one even though
the bearings were trashed.

Reply #3October 23, 2009, 02:31:05 pm

smutts

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Re: IP pressure Dynamic / static timing help please
« Reply #3 on: October 23, 2009, 02:31:05 pm »
Quote
IP pressure was around 12 psi at Idle

Wow, I thought mine was bad at 18, :P.

Just a thought to those who have the Bosch ESItronic discs, can anyone look up the pump pressures, please, pretty please with sugar on the top. ;D

Final thought, sometimes continental engineering gives the pressures as absolute, which is measured against a vaccuum. In other words, atmospheric pressure (14.7psi) is added on to the values. So 25psi absolute would be near enough 10.3psi for normal people, just a thought to add to the confusion. 8)

Reply #4October 23, 2009, 02:44:30 pm

smutts

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Re: IP pressure Dynamic / static timing help please
« Reply #4 on: October 23, 2009, 02:44:30 pm »
http://www.vwdieselparts.com/forum/viewtopic.php?t=5936

Here is a link to another forum that has plenty of suggestions on pump pressures. 8)

Reply #5October 25, 2009, 12:04:05 pm

MizpahPAH

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Re: IP pressure Dynamic / static timing help please
« Reply #5 on: October 25, 2009, 12:04:05 pm »
I installed the original oil pump with rotella 15w40 oil and a mann oil filter

Pressure is still SCARY high cold when cold... When it does warm up the pressue is about 20 psi lower than the
other new pump.

Before I installed the old pump I checked the action between it and the new after market pump.
Completely diffrent action.

The aftermarket pump sucked oil with just a few hand turns of the drive and it ratched really bad.
The original pump would not prime by hand so I filled it from the top with oil and turned it by hand it sucked really good
pumped oil about a quarter the oil and did not ratchet half as bad.

It does run a lot smoother with the original pump and it might be me but doesnt seem to work as hard?