1988 Dodge Lancer high idle

052361

MEMBER
1988 DODGE LANCER
150,000 MILES

I have a 88 dodge lancer with a 2.5L tbi sohc. I replaced the cylinder head and the two manifolds as a unit, with the same from a 93 Plymouth Sundance, from salvage.I also replaced the tbi flange gasket and cleaned the throttle body, After finishing the job the car started right up and sounded good except for the rattle at the front of the engine compartment( idler pulley I think) Warmed up the engine, found no leaks, set the timing and drove it around the block, power was good. Check engine light comes on. When I pulled the codes I got a 12 and13. I had a vacuum leak at the MAP sensor, so I repaired that and the light doesn't come on anymore but now the idle is way high. That is if you can believe the meter in the dash, but it sounds like it is running to fast. The meter says 1500 twice as fast as it should be. I really don't know what to do next. Would the vacuum leak at the MAP sensor cause the timing to be that far off. I'll reset the timing when the sun comes up. But. Until then can anyone out there can help me with this? What do I do next

1 Reply

HMAC300

MECHANIC
48,601 POSTS

Check for vacuum leaks in these areas. Throttle body (2 front, 2 rear).
Purge solenoid.
Charcoal canister.
PCV valve to intake manifold vacuum port.
EGR backpressure transducer.
MAP sensor.
See if purge solenoid is leaking on both sides it shouldn't at idle. Or block off the one inlet line and see if it goes down. Recheck all your connections then see if you can turn the idle down on tbi unit you may be able to clean tbi with choke cleaner as well. It may be partially stuck. Also check the idle speed motor, you may have to drive the car in order for it to go down drive at least 40 mph