cause my idle to sort of roll? when I take the MAP sensor away from the vacuum source, the engine stops rolling but dies down to a real low rpm..when I put the vacuum line back on it starts to roll again...should I look into getting a new MAP sensor?

 

I don't think it could affect your idle because the map is a load sensor, unless maybe there is a vacuum leak in the line going to the MAP sensor but even so that would give a higher idle.

Taking away the MAP sensor from the vaccum source would cause the engine to idle worse so I think it's good.

But what kind of voltage reading do you get from the map sensor at idle? I believe it should be like from 1 to 1.5 volts. How does your engine feel at load?

Have you checked your IACV? Did you get a CEL?

 

no CEL new IACV...no vac leaks either....could it be TPS?

 

Did you have this problem before you put the new IACV on? And when you did, did you use carb cleaner in those 2 holes in the manifold where the IAVC goes?

It could be a bad TPS. Did you clean your throttle body lately?

 

yes it did it before the new IACV....I just swapped manifolds so both the mani and throttle body were thoroughly cleaned with carb cleaner

 

It's probably the tps then...make sure it's the tps, you don't want to replace a part thats good.

How does the engine feel under load?

What you can do is a tps sweep test with a multimeter. Get a thin wire and remove the connector to the tps, find the reference wire and put the wire in between connector and tps. Turn your key onto the on position but don't start the car. Put the positive lead on the wire and ground the other at the enginem move the throttle plate from idle to WOT and look at your voltage readings. It should go from like 1 to 5 volts. Actually check your voltage at idle and find out the spec.

 

I have seen a bad MAP sensor cause a rolling idle (only once though and the CEL was on) It could be that possibly or its the IACV or a vaccum leak.

 

vaccum leak and IACV have been ruled out...ran all new lines and just put a new IACV on my p-30 intake mani...no leaks....I think I am just gonna replace the MAP and TPS....if that dont work....I am gonna keel somebody....

 

map sensor is on the throttle body. if you look at the back of the throttle body they have carved out a route for air to go uptowards the map sensor for reading. there are no vacuum lines connected to a map sensor. vacuum lines are all on the intake manifold.

if you unplug your map sensor while the car is running your car should turn off.

Am i even in the ballpark of this thread, I feel as if I'm talking about something completely different.


What's the problem?

 

actually...since I am running a gen1 throttle body there is no place for the map sensor on the throttle body..therefore you have to put a T fitting into where the fpr goes to the intake mani and then mount the map sensor somewhere on the firewall.......I am just going to get a b18c throttlebody with map and tps on the throttle....if that doesnt fix this shit...I am just gonna go crazy...