1982 Westy with 1.9, Holset turbo. Early morning last Tuesday my wife and I took off on a 1700 mile round trip from San Diego to Eureka, California to visit my daughter and two grandsons. We slipped into the millions of others heading out for the holidays and by the time I had made it to LA, I began to have some serious issues.
Typically I can boost to 10-12 psi if I floor it which will get me up most grades at 60 mph. In the stop and go holiday traffic going through LA on the 5 North, I didn't realize just how bad things were getting. By the time I reached the long 6% grade leaving San Fernando and heading up towards the Summit, my boost was only going to 7-8 psi which kept my top speed at 50. Once I hit 7 psi, any more pedal just made it stumble and rapidly loose speed. Needless to say, I made it all the way to Eureka with this issue - going into severe headwinds to boot!
I stopped several times, cranked the fuel screw in, look apart the LDA - even removed the star-wheel to lessen the load on the diaphragm spring - no improvement whatsoever.
Once we arrived at my daughters place and after having many many stressful hours to think about it, I decided that the 12 volt pump I had installed several years ago had something caught inside it and was blocking my fuel delivery. I know an electric pump is not needed as the IP can pull plenty of fuel without it. I just installed it for the odd time I may run out of fuel (never have), it would be nice to help get the air out.
Anyhoo, I replaced the pump and the entire line from the new fuel tank I recently installed. I did find a few tiny bits of rubber or sealant in the pump and sure enough, it now boosts to 10-11 psi and climbs most any hill at 60, even 65 if there's no headwind.
My apologies for the long winded post but I am looking for advise on what it will take to get this thing to fuel more than it does. My long trip and subsequent fix proved clearly how boost and fuel are directly proportional. I have turned the fuel screw all I care to as the idle screw is backed out to it's max. Any more fuel and it will simply raise the RPMs and I'd like to keep my idle at 850.
For a bit of history, the pump is from a 1.6 (was like that when I bought it). I had the pump tweaked by a pump guru in Canada named Giles (highly recommended by the folks on this forum) and at that time I had told Giles I was running a KK-14 turbo which generally maxes out at 12 psi. However, the Holset turbo I finally ended up installing can do 20 all day and I built the engine to take it. My thoughts are that Giles tuned the pump for the 14 and no matter what I do, it simply can't deliver the required fuel to boost past 10. I recall that when Giles informed me that I had a 1.6 pump, I asked him why the PO may have done that. His response was that the 1.6 was a bit smaller but not to worry as he could make the pump fuel plenty - again, he was tuning for the KK 14.
Also, as I mentioned earlier, I recently installed a new fuel tank - stock tank probably for gasoline. As I was swapping out the old hose/fuel pump affair, I noticed that the fuel came out of the fitting on the nearly full tank quite slowly. It's not a dribble but it is certainly less than I was expecting. I did straighten out a coat hanger and jam it quite a ways in to the tank output tube just to make sure it was clear. The hanger wire did stop against something quite a ways into the tank but I have no idea if it was a screen or just a sharp bend in the output tube. Regardless, it didn't change the flow at all. I still wonder of there is a very fine mesh screen in there that would allow gas to flow easily but is somewhat restrictive when diesel fuel tries to get through.
I should mention that I have posted this on the SAMBA as well and those folks will possibly know more about the fuel tank than most of the folks here.
If anyone has any thoughts on a possible tank screen and how to clear it, or if the 1.6 pump is too small, or a way I can get this pump to move more fuel, I'd really appreciate it.
The van runs great now but If I could get at least 15-16 lbs of boost, It would be wonderful!
Thanks for reading my novel and please share any ideas you have as to what the problem may be. I have checked for boost leaks and only found a few tiny ones which I have fixed. Stopping these really didn't change anything either.
Jim