Thank you for chiming in ORCoaster. Diagnosing problems with these pumps is NOT my forte'. In the end, I can usually correct what needs to be corrected, but figuring just what that is, is the conundrum.
Before I decided to do this Giles pump swap, the aaz with pump I had was working great. I had no issues except for one hiccup....a gentle surge at 2000-2500 rpm at no-load driving. It was annoying, but still drivable. I decided that now was a good time to swap pumps, since I had acquired the Giles pump 2 years ago, and had intended to swap it in eventually. I thot.....bolt the Giles one on a go! How hard is that?? The rebuilt aaz has maybe 1500 kms on it, and everything, filters, fuel lines, etc, is all brand new. I know there are no problems with any of that.
Today, I re-installed the injectors and hard lines that I had on previously. I also removed the delivery valves, sprayed BP blaster in the pump head holes to flush, disassembled the valves, cleaned with PB Blaster, reassembled them. Each valve keept it's unique parts, and valve went back into the hole it came out of.
Then I primed the hardlines, and started it up. It sounded much better upon starting...no clouds of smoke, etc. BUT, it wanted to rev from zero rpm to ?? 3000?? in the 1st second of running. WTF now?
I shut it off immediately, backed the "idle speed screw" out further, and tried again. Upon starting, it went to ?? 3000? rpm in one second again, so I shut it off asap, as soon as heard it was not a tolerable idle rpm.
Why is this happening?
Could it be residual fuel in the engine from trying to run on 2.5 cylinders last night?
As far as I know, the PO did not mess with pump screws after his engine packed it in. In theory, the pump should run [ an aaz engine ] as good today as it did 3 years ago, the way it's set.
But it ain't
The PO told me, he was driving along, and he heard / felt a "bang". It was night. He thot he ran over a stick or some other object on the road. Other than the bang, the engine and everything else ran well...
..until the low oil alarm came on......he pulled over right away, saw the trail of oil on the road, and knew he had a problem. Had his vw towed home.
Upon inspection, he saw a hole in the engine block, and knew that was the problem. He said he was surprised that the engine ran so well with a hole in the block, and if it weren't for the oil alarm going off, he would have had no idea of the damage.
At that point, he pulled the engine and it sat unmolested until I showed up and bought it. So, in theory, the pump should be working just fine as is.
About the pumps idle speed screw......I have read that up until 1985, the pumps did not have that long idle speed screw and linkage, or even the cold start mechanism. They had a screw with lock nut, on the LDA base, that served as the idle speed screw. To me, this looks to be the same screw as what is called "the residual fuel screw" on the newer pumps today. Is this correct?
Did Giles send these pumps out like this? missing the long idle speed screw and linkage? Mine does have the cold start mechanism tho.
I did install a long idle speed screw and linkage, since I had a spre on hand, and since I thot it easier to do it with the pump off the engine, than find out later on that I do infact need it, and then have to re and re the pump again, just to add it.
Ok......so how do I get this pumps rpm down on start up? and get it to idle?
I'm not removing the throttle lever and repositioning on the shaft......because I'm sure it has not been dicked with.
Thanks for your help