Bruch

Hello,
Working on a '97 2.8 12v with manual transmission.
I want to test the fuel pressure to the injectors, and make sure the regulator is doing its job. Bentley say 'connect guage between supply and return lines, and I can't see from the picture how they want you to do it.
I have an OTC guage and a variety of fittings that I haven't used in years, since I had the Scirocco (CIS). I'm thinking if I put it in line on the feed side of the regulator, I won't be able to tell if the regulator is working. Maybe someone can tell me how they did it.

I'm trying to fix a rich condition, that's causing hard starts and some rare stalling. I have to pull the fuel pump fuse to get it started, then plug it back in. I think the root cause here is my Coolant temp Sensor, but I can't get it out of its hole, and I don't want to force it until I have a new one in hand. I got the clip off, I can twist it with pliers, but it wouldn't come out.
My spark plugs are black and the tailpipe is sooty.

I just bought this car as a project and drove it for 2 weeks before this problem surfaced. I found last night that the vacuum hose routing was Fubar, so I got that straightened out today. Basicall, there was no vacuum ever to the regulator, EGR or manifold change-over systems.
I tested the injectors for drips, and they passed. I originally thought that was going to be my problem.

Sorry for the long post, but I thought it important to provide some background.

Thanks in advance
Bruch

Lago Blue

Hello,

Firstly, I have not done this procedure, but I think that if you want to see what the FPR does to the fuel pressure, you must put the gauge between the pump; and the FPR.

The pump delivers the fuel; and the FPR controls the fuel's exit from the rail. One knowledgeable contributor mounted his gauge permanently mid-rail. See photo here (I can't seem to post the bleeping album photo!):

https://www.audiworld.com/forums/alb...ctureid=220546

Other FPR tests might include (while you're there:

- varying the vacuum to the FPR and noting FP changes;
- do a leak-down test on vacuum side of FPR;
- check for fuel leaking through to vacuum side;
- check for fuel leaking by the two internal O-rings due to age or damage (dealer carries these as replacement parts)

I have only ever done the last three above.

Do you have any stored DT codes?

I think your proceeding logically. Is the rich condition perhaps simply a symptom of something else (other than FP, such as the CTS) preventing the engine from getting to closed loop?

You may be able to test your CTS in situ, warm and cold, for electrical resistance IIRC; and compare those numbers against the numbers in the Bentley (I can't recall the ranges).

Might you have some air leaks that are contributing to the hard starts and stalling?

What does your engine pull for vacuum when fully warm?

Bruch

Thanks for the response, sometimes I think my questions don't make sense to anyone but me ;>)

I felt the CTS was the problem all along, because I was getting erratic readings at the gauge end. But I also thought that doing a leak test on the injectors, along with FPR function would be "due diligence." I hate just throwing parts at a car without at least having some data to back it up.

The photo link you included is appreciated. I read the thread concerning how he brazed the fitting onto the SS fuel rail. Way above my welding skills, I have been trying to find a spare fuel rail that I can have modified like that to at least put a test port on the rail.

So the injectors passed the leak test, and I changed all 12 o-rings as a matter of good practice. I was very happy to find no leaking injectors, they are very expensive!

It also turned out the previous owner had the vacuum line routing all buggered up, so that the FPR wasn't getting any vacuum, ever. No wonder I was getting codes left and right for Oxygen sensors, EGR insufficient, etc.

Car runs great now, thanks for responding

Bruch