HELP 99 SAN limp mode and surges at idle

[AirTool]

if the light is on and it's in limp mode why wouldn't one of the two sensors cause this? The rough idle i can deal with but the limp home I have to look into, friend has a dd gt40 and I spoke to him today and he said his has a irratic idle and has been riding for 2 seasons, just worried about the limp home mode

Limp mode (or S.L.O.W. for this engine) only restricts engine speed to 2700 rpm. Performance below 2700 is NOT affected by limp mode.

If you have problems below 2700 rpm, (like rough idle) you have a problem not related to the two limp mode switches.

Several of the EEC sensors cause a fast idle when they fail. (fast being controlled by the EEC to keep the engine running.)

The MAP sensor will cause a hunting idle or the engine to stall.

There are other problems that cause rough idle.

[DanielC]

50 PSI is too high. It should be 39 plus or minus 3 psi, at WOT, or checking with the key on, engine off. The engine does not need to be running to check the fuel pressure, however, it is good to know what the fuel pressure is AT THE TIME YOU ARE EXPERIENCING PROBLEMS.
This is how I check my fuel pressure.
http://www.planetnautique.com/vb3/sh...=fuel+pressure