Mechanics

MAP SENSOR

1989 Cadillac Hearse

Engine Performance problem
1989 Cadillac Hearse V8 All Wheel Drive Automatic 72,000 miles

we did a tune up on my caddy and immediately check engine came on. We had it tested. Said map sensor went out. After 3 weeks to find RIGHT ONE and had to redo map sensor AND redo new harness. The light STILL comes on. We undid the battery for a half hour and put it back together and lite STILL comes on and runs worse than ever. Idol off or timming. Any suggestions? I need help
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Carolrae
August 19, 2010.



Do you have a good vacuum supply connected to it?

Wrenchtech
Aug 19, 2010.
Do you mean from the little hose that gets connected to the mapsensor itself underneath? I havent tried it. Do I try it with car running? Im a female and ive been workin right along the man workin on my tuneup. So I do know the hose you might be talkin about. How can I tell? Put paper to it and see if it sucks to it>?

Tiny
Carolrae
Aug 19, 2010.
That's what a MAP sensor does. It measures he engine vacuum so it has to have a good sealed line to the vacuum supply. You should be using a vacuum gauge to measure it. If that's not the problem, then your going to need a scan tool to read the sensor data in the ECM. You could have a wiring problem.

Wrenchtech
Aug 19, 2010.
Thanx for advice. Immediatly after a tune up the map sensor gave problems. We replaced original one with a whole new senor type and harness cus the 1989 piece was obsolete. So they say cuis it took 3 weeks of searching for part. We will heck the vacume and wires to night. THANK YOU! So much for helpin us out here. Hugs

Tiny
Carolrae
Aug 19, 2010.
Dear carolrae -

It is possible that my 1990 Cadillac is similar to your 1990 Cadillac Hearst. I am sure these vehicles are becoming somewhat obsolete. I would be interested in talking with you about your vehicle. I may be contacted at email "ferrycha@hotmail. Com"

Thank You
cferry1

Tiny
Cferry1
Jan 20, 2012.