'95 LHS 3.5L Problem

A friend has a 1995LHS 3.5L with 150K miles. Symptoms are high idle (about
1200 RPM) and intermittent engine problems. He also gets a 41 diagnostic
code. I'm not sure if they are all related or not as I have not actually
seen the vehicle and am trying to help him via the phone. He says he has
been trying to find the source of the problem for about 9 months now but has
not been successful. When the engine acts up, he says there is no pattern.
It can be at low speed or on the highway cruising at high end. He says that
it has never left him stranded and always seems to get better after a few
minutes, sometimes by pumping the accelerator and just driving through the
poor performance period.

What he has told me he has replaced thus far over the last few months are
the gas filter, fuel injectors, fuel regulator and fuel pump. He tells me
that he has also fixed an intake manifold leak as well and replaced several
dry/cracked vacuum hoses. He says all the hoses are on and none are leaking
since I thought this might have explained the high idle.

Does anyone have any ideas on what could make the engine intermittently run
like cr**? He says it reminds him of a fuel delivery problem, but this is
not likely given that almost everything has been replaced. He has asked for
ideas and I suggested looking at his EGR since he was not sure if it had
ever been replaced. I told him I would post the symptoms here to see if
anyone else had encountered this previously and had a thought. Thanks in
advance for your ideas and comments.

Bob

 

Were fuel rails replaced under recall? They should have been.

Did he clean throttle body?

Visit www.google.com the groups page and you can search this group for other
possibilities.

 

Art,

The fuel rails were replaced long ago under the original recall and per my
friend do not appear to be leaking. He said he put new O-rings in with a
new rail when he did the injectors. (This was because he said his son broke
one of the rails while doing that job.)

I didn't ask about the throttle bodies (actually there are two on this car)
since I thought it would only cause a rough idle and did not affect
operation beyond idle.

Another thought that has come to mind since posting the note last night is
possibly the Intake Air Servo/Controller. If this wasn't working correctly
it might cause the high idle speed, but would it set the code "41"?

Thanks again for the input.

Bob