I bought an 80 Vanagon camper with 78,000 miles on. After many months of work it is on the road and off the jack stands. It has taken a longish trip from PA to New Hampshire and back. During the trip the van could keep up speed on the level but not much of an incline would slow it down. I have tinkered around with it and it still seems to lack power. The power loss seems most noticeable at low and mid RPM. When starting from a stop if the engine RPM must be keep up or the engine will have no power or stall (manifold leak?).
Compression
#1-115 #2-137 #3-118 #4-133
Compression test with oil
#1-132 #2-142 #3-132 #4-150
It appears that sometime in its past the rear cylinders over heated.
Timing
850 rpm, 6 degrees ATDC with OR without vacuum hose attached (is this right?)3000 rpm, 30-28 degrees BTC vacuum hose attached, 20-18 degrees vacuum hose off.
Engine has new fuel filter, plugs, points, rotor, cap, condenser, air filter. The plug wires seem new.
Engine starts right up and idles smooth.
After 750 miles the plugs are white.
Fuel pressure close to limits.
There is a fair amount of air coming out of the crankcase breather port when the PVC valve is removed.
With hose attached to the fuel pressure port I'm pretty sure I got close to the liter per minute the manual specifies.
I am not so sure that the manifold is not leaking. Should that be more of a problem at low speeds? Is there any easy way to test for manifold leaks?
The plastic cap on the intake air sensor was loose when i got the van. I have "fooled" the running engine by making the engine think there was more or less air flowing thereby changing the mixture.
With the engine at idle I have simulated increased air flow. At first the engine speeds up a bit and then the speed rapidly decreases.
With the engine at higher RPM the same thing seems to occur. With throttle fixed, simulating increased air flow causes the engine to at first increase in speed and then to rapidly slow down when the mixture gets too rich. Do you richen the mixture a little past max RPM?
Any help on what I should try, I'm feeling pretty stumped right now and I'm pretty sure there is more power to be had.
Thank you for any thoughts.