Join Date: Sep 2007
JohnN is offline
MAP sensor, runs better unplugged
(Different problem then FPR, so I thought I’d start a new thread.)
88 S-10 Pickup, 2.5L, 5-Speed, 130k miles.
Truck will only start if I put fuel down the carb. Then, it sputters, spits and coughs, and will only stay running if I pump the gas pedal. No codes on the SES light. When I unplug the MAP sensor, it smooths right out, and will even idle on its own for several minutes until it finally dies. With the MAP sensor unplugged, I get SES code 34 (bad MAP sensor of course).
So I put on a brand new MAP sensor. Same problem, sputters, spits, coughs. I then unplug the MAP and it runs okay again (until finally it dies after a few minutes)
Here’s a list of what I’ve checked and replaced:
Checked for vacuum leaks-none found
Removed Cat. Converter (in case it was clogged)
Checked for alternator loose connection (in case FP wasn’t getting enough power)
Fuel pump relay-replaced
Dist. Cap and rotor-replaced
Air box temp sensor-replaced
Air box manifold breather-replaced
What I have NOT replaced:
IAC (Idle Air Control) Valve
Also sprayed in some carborator cleaner, and put in some fuel stabilizer cause I thought the gas might be old. Also ran it down near empty then put it new gas.
I’m slowing running out of ideas and things to replace. This is driving me crazy! Anyone have any idea what could possibly be wrong?
Thanks in advance.
Last edited by JohnN; 10-23-2007 at 08:45 AM.
Reason: corrected info