internal injection pump pressure

[Quantum TD]

Gonna try to pull this one up again. What all are people using as photo tachometers? Any brands you all prefer?

[Fatmobile]

I'm using a Ferret 765; pulse detector,..
running a snap-on inductive timing light,... with digital tach and timing advance.

[Quantum-man]

I'm using a Ferret 765; pulse detector,..
running a snap-on inductive timing light,... with digital tach and timing advance.

I've got a ferret, but he's no help with the car; he tends to steal all the rubber

Coincidentally, his name is 'V' named after Vee Twin (His former owner was a Harley fanatic, and had two ferrets ,but alas 'Twin' died)

[libbybapa]

I have a snap-on pulse adapter and an actron strobe with the tach function.

Andrew

[Typrus]

I know this is the IDI section, but is this as vital on the 1Z IP? And would the adjustment be the same? If so.. I have some playing to do. Not to mention when I get the 1.5 IDI running.

So would putting a feed pump of 4-6PSI (say, a Carter rotary?) badly effect things? I read that the effect on the pressure differential could potentially retard timing a bit, but how much of an effect will 4-6PSI have on 100 PSI?

[libbybapa]

Is the 1Z a stock fully electronic install? If so, then this is not nearly as necessary as the timing is somewhat electronically controlled. It would only be necessary if it got out of spec to the point that the computer could not compensate.

A low pressure lift pump will not significantly affect the timing.

Andrew

[molgrips]

Brilliant thread!

My 1.9 AAZ runs rough over 2krpm, so I am wondering if there's too much dynamic advance. I'm going to try cleaning the out banjo, see if that helps. Maybe it's blocked with crud or something.. it's been running on a variety of fuels in its lifetime, that much I know - so it'll be interesting to see what it looks like in there.

[Quantum TD]

I have a snap-on pulse adapter and an actron strobe with the tach function.

Andrew

Hey Andrew and Fatmobile,
What do you set the timing to when you do it this way? I'd assume the flywheel marks. Do you use the 8 degrees BTC mark on the flywheel, or is there anohter manner to this?

Thanks

[libbybapa]

I got a baseline reading (wrote it down somewhere, but would have to dig to find it) from a fresh pump and calibrated injectors. It didn't correspond to any timing mark.

Andrew

[Quantum TD]

I got a baseline reading (wrote it down somewhere, but would have to dig to find it) from a fresh pump and calibrated injectors. It didn't correspond to any timing mark.

Andrew

So do you use the pulse adapter for timing, or just reading RPMs? I read one of your threads on a Benz forum regarding the used of the timing light and pulse adapter for timing. I guess it doesn't really work on the Vw then huh?

The reason I ask is, my Caddy is getting a wretched 33-38 MPG. I know the injectors are wasted, and I'm working on them right now. But, the pump hasn't been calibrated either since the last two EPA mandated fuel changes.

The pump really sounded lousy at 1.00mm setting. So, I backed it down to .90mm and it runs a bit smoother, but I haven't filled up to see if it's improved on MPG. Even so, it sounds like marbles in a can at about 1800-2000 RPMs. Once its warm, it goes away. I know the worn injectors are causing the noise, and (presumably) advanced timing. I could back it off a bit more, but I'm afraid cold-starting might be a bit worse.

Since I'll be selling the thing eventually, I really don't want to rebuild the pump; I just want some decent MPG figures as a selling feature. I figured I'd spend the money I would have spent on a rebuild on rebuilt injectors, and the tools to set the internal pressure. I can reuse the tools, and (in theory) I could hopefully get some decent MPG figures. Or, I could be a total cheap-a$$ and just try to back the timing down for optimal MPG buy using the pulse adapter and timing light.

Anyway, just wanted to know if it was feasible to time the car that way for optimum efficiency.

[libbybapa]

Yes certainly it can be used for timing on the VW (once you have a baseline reading) and does so more quickly and more accurately than a dial indicator as it measures the actual start of injection and so compensates for injector opening pressures and pump wear. The tools are, however, are a fairly expensive investment and certainly don't guarantee a vast improvement in economy.

Andrew

[rabbit_man]

This is kinda technical so I hope it makes sense......
I have a question,
Last week I changed my pump bushing and I was very careful not to mess any settings up. I did swap all the guts from one pump body into a different body I had. I used ALL of my old internal parts hoping the calibrations wouldn't change, right away I could tell they had....

The first thing was even though I set the timing right for idle, by ear like before, I could easily tell that it wasn't advancing enough at highway RPMs. It was so bad I could hardly hold 55mph on a flat road with no noticeable wind, EGTs were at 650F, normal is 450F for those conditions, if I tried to accelerate the EGTs shot up and it started smoking with very little gain in speed.
I used the same timing spring and shims and didn't adjust the pressure regulator.
So I checked the pressure, my gauge vibrated pretty badly but here's the numbers: 40-45psi@1000rpm engine, 72-76psi@2000rpm engine. Same as before the pump redo. First I removed some shims from the behind the timing spring and that caused very loud clatters at idle and also the timing piston was no longer affected by the advance knob. So I retarded the timing by turning the whole pump towards the cars front, that fixed most of the clatter. Now I'm trying to fix all of the clatter.
Heres what I've done:
I put some shims back in the timing cover to keep the piston back all the way, it still clatters but it also misses slighty for about a minute, with the engine warm to the touch.
I can't see any way to make it stop advancing so much at idle and still advance enough for high rpm without bumping the internal pressure down a bit. Does this make any sense?

[Josh8Loop]

Fellas,

Just though I woud share a little bit about my injection pump pressure deaings:

I went to the junk yard and obtained a stainless steel fuel rail fuel pressure test port from a chevy or chrysler vehicle(for free). These are the pressure test ports that are on gas vehicles, and they have a schraeder valve in them, and a black plastic cap that keeps dirt from the test port internals. I cut the test port out of the vehicle with tubing cutters, and left about 2 inches on either side of the test port. After some injection pump research, I located a direct path to the inside of the IP that I could hook my pressure test port to in a pretty straightforward fashion. I took out the bolt/vent plug on the back of the injection pump(the side facing the engine), and drilled a .080 hole straight through it. Once the hole was drilled, I cleaned the bolt/vent plug and got it ready for brazing. I also prepared the pressure test port by first removing the schreader valve(so it wouldn't burn while brazing), and cutting it down a bit so it would fit directly on top of the bolt/vent plug. I went ahead and brazed things up, cleaned the assembly, and checked for braze continuity.

Everything looked good, so I placed the schraeder valve back in and torqued it back onto the injection pump. By the way, without the black cap the new pressure test port doesn't interfere with tightening the bolt/test port if you use a socket. This gave me a nice handy test port, and I could use my current fuel pressure test guage that I use on my wifes gasser. The best part about this mod is that I can place the black cap on the test port, and since it is on the back of the IP, you would never know it was there!


Some photos:

http://s877.photobucket.com/albums/ab334/jamsue4him/

[TonyB]

There are some very good digital optical tachs available to measure diesel RPM. Amazon sells one for less than $25. They work great!

http://www.amazon.com/Digital-Laser-Pho ... B000EUT9ZS

TonyB
Jacksonville, FL
81 Dasher 1.6na

[wolf_walker]

Fellas,

Just though I woud share a little bit about my injection pump pressure deaings:

Some photos:

http://s877.photobucket.com/albums/ab334/jamsue4him/

That's a pretty neat idea, what motor is that on, I swear I see cooling fin
in one shot. I'm not sure there is enough room on the back side on the vw car apps, maybe with a 90 degree adapter. Or maybe there is more room than I think there is.