MAPed Blue Top Swap, NOT staying running! Please Help?!

[jondee86]

Try it with the MAP sensor hose just hanging free... not connected to
any vacuum port... and don't forget to block the spare port off

Cheers... jondee86

[Nanaki]

If its unhooked It does pretty much the same as if it was hooked up to the front of the throttle body.. If I take the plug of and then hook the map sensor up to one of the three in the back it will die.. Maybe the map sensor is bad??..

[Ivan141]

Have you checked the sensor connections @ the back of the cylinder head already? I once plugged them in incorrectly on an ae86 after swapping an entire wiring loom, and the car had very similar problems to yours.. would run poorly with map connected, and die very easily with it connected. The ECU was throwing some code about a faulty TPS sensor at the time, but there was nothing wrong with it.

[Nanaki]

Which sensors? The two at the back that look like injector connectors? How do I make sure they are connected right? I mean is there a way to tell which goes to which?

[Allexz]

now i have not red anything.. but a vacuum leak seems a good reason . My had it.. It was the vacuum splitter on the intake that was loose. i fixed it and it stayed on a good idle

[jondee86]

The main task for the MAP sensor is to input load information into the
ECU. In general, high vacuum corresponds to a closed throttle, requiring
less fuel, and low vacuum indicates an open throttle, requiring more fuel
from the injectors.

A disconnected hose means the same thing to the MAP as WOT. The ECU
will increase the injector duration, although I'm not sure how it handles
the fact that the TPS is indicating a closed throttle

If you have low pressure in the fuel rail, opening the injectors for longer
will let a bit more fuel into the engine. This probably helps your idle.

I'd still be looking to confirm what pressure/flow you have to the rail.

Cheers... jondee86

[Ivan141]

As far as the sensors at the back of the head are concerned: They are supposed to be colour coded.. one is brown, the other is green or blue or something like that. The plugs are exactly the same, so it's easy to get them crossed if your not paying attention.

[Nanaki]

I will try to check both of these things as soon as I can and report back.