"Sticky" MAP Sensor?

[BlkTy2186]

Okay, let me preface this by saying that frankly, Im a virtual beginer when it comes to cars and that I have no clue what MAP stands for, but heres my problem and what I was told:

Im stationed in northern Japan, managed to pick up a Ty over here. Needless to say, the winters are a bit longer and colder than what Im used to. When I start the truck up in the morning (typically colder even in April) the turbo gague sticks at just below zero and the check engine light comes on. During this time, the engine has no bite and the turbo will not spool up. After about 20 or so minutes, when the truck has had a chance to warm up, the needle will drop and the check engine light will go off.

I called a shop back in the States that specializes in Tys and Sys, described the problem I just detailed almost ver batim, and was told it was a "sticky" MAP sensor.

Just looking for second, third, fourth opinions, sound copacetic?... thanks!!

 

[dgoodhue]

One post is enough, this is a small community. I guess you could deduce it could be the Map sensor, but maybe the vacuum line are leaking when cold but sealling when warm or the Gauge clsuter is flaky.

MAP stands for something like Manifold Air Pressure. Normally at idle it would around -10 on the vacuum boost gauge in hte cluster and around +15 at WOT under full boost. However, The factory gauge is notoriously inaccurate, but not that inaccurate as you described..

 

[BlkTy2186]

Yeah, sorry for the double post, dont know why it did that

Thanks for the feedback though, and I did order a new MAP sensor... now just need to find it to replace it

 

[dgoodhue]

Looking at the engine on the driver side of the intake just inward of the vavle cover, whne you have a new one in hand it will be obvious.

 

[Divergent Lightning]

You do have an aftermarket boost gauge on it correct?

 

[BlkTy2186]

No sir, I sure dont. Bought the truck 99% stock (it was lowered) -- I'm in Japan, and dont exactly trust a Japanese mechanic to do much of anything to it. The base Im on has mechanics, but theyre not certified to work on American cars, and barely 1/4 of the people in the do-it-yourself garage even know what a Ty is. I asked them which hose Id tap into to install an aftermarket gague and the "mech by committee" couldnt make its mind up. (Again, I'm a newbie when it comes to cars) So I'm pretty much conceding that I'll have to wait until Im back in the States to do much of anything

 

[Divergent Lightning]

The stock bost gauge is not accurate in any respect of the word save for that it can tell you when you are boosting and when you aren't....

I would get a boost gauge installed on it ASAP. Just a good thing to do. It is on the list of things to do to you SyTy. Along with replacing the IC lines with rubber ones and the such...

As for installing it, board members can tell you what needs to go where. Don't trust a vague estimate of where it might hook up. Stuff breaks that way.

 

[AlaskaTy]

MAP = Manifold Absolute Pressure. It's how our trucks measure the air flow coming into the engine (fulfills the same duty as a mass air sensor on newer vehicles)

 

[Slow-Clone]

MAP = Manifold Absolute Pressure. It's how our trucks measure the air flow coming into the engine (fulfills the same duty as a mass air sensor on newer vehicles)

Yes, but not quite. MAP sensor's simply read and report if and how much boost/ vacuum the intake is seeing. They have no means of measuring the flow. A Mass Air Engine will still have a MAP sensor, just to tell the computer pressures, not volumes.

 

[dgoodhue]

Yes, but not quite. MAP sensor's simply read and report if and how much boost/ vacuum the intake is seeing. They have no means of measuring the flow. A Mass Air Engine will still have a MAP sensor, just to tell the computer pressures, not volumes.

Not all cars that have Mass Air Flow (MAF) have MAP sensors or inthe case of TTA and GN's aren't hooked to the ECM. My Corvette doesn't it just uses a MAF. The MAP use air pressure to measure the volume of air in the engine (this is also happens to be the load on a engine). The map tables are calibrate for the particular system, so in some way it is measuring air volume. However as as MAP car is modified and the air volume is increased (ie better flowing cylinder heads), the ECM doesn't compensate for it because it is cabrated for the stock system. MAF respond better to air flow changes because it measuring air flow. One might wonder why MAP are even used. MAP systems can tuned to a greater precision.