Why 95's do not need modification to MAP sensor for boost.

[DSMcrazy3]

Well I did some searching, and this is what I found.

Again, this goes with the OBD 1 OBD 2 argument that so many of us have.

I believe that all 2gs are OBD 2, just the parameters of 95s and early 96s are rather basic.(manufacturer was not completely finished with OBD2 system at time of production).
The 96-99 ECU will throw a CEL if the MAP sensor reads more than 4.63v for more than 2 seconds. Since that reading is at 0 PSI, any greater amount of pressure in the intake plennum will cause a higher voltage reading, sending a signal to the computer, telling it to cut fuel. In an attempt to keep the engine from blowing itself up, due to compression.

This is just one feature the 95 fell short of. I am not sure of what affect the higher voltage reading has on the 95/early 96, in terms of fuel supply, I will try alittle more searching and see what I come up with. If anyone else has the answer please post. For others to view and learn from.

Hope I helped,
Josh

 

[XMasta19]

I have a 95 as well with the non fully compliant OBD2, and I hit 12psi w/o fuel cut z
....no map devices, boxes, fcd, missing link, etc and what not

 

[Civib2]

Thats not entirley true, I have a 96, it has the later fuel system with the stock FPR in the rear by the tank, but it has the early ECU, I was boosting for 4 months with no codes, map sensor didnt flip out at all. So its really kind of weird my car was built in June of 96

 

[RicecarRST]

This is interesting. I have a 96 Eclipse and was told that the ECU is early OBDII. I have been running the Synapse Missing for over 2 years now and its worked great. Although I have been looking into just replacing the MAP sensor for a turbo MAP sensor. I mean why couldnt us 420A guys use the same MAP sensor as the SRT4 guys do? Or even the MAP upgrades they get? I havent found any info on this yet but if someone has the info it sure would be interesting to find out why or why not. All MAP sensors run off of the 5v parameter.

 

[DSMcrazy3]

The ECU is most likely different in the SRT-4 than our DSMs

 

[RicecarRST]

"Most likely" But you dont know. Well Iam going to do some research to see if they wil work and if they wont why?

 

[DSMcrazy3]

"Most likely" But you dont know.

and neither do you..Please do search, add anything to this as long as it is truthfull and informative, so people like you and I can learn

Goodluck

 

[RicecarRST]

Well of course. Have you found anymore info on the fuel delivery of an early OBDII and OBDI when above 4.63v or 0psi?

 

[Raph]

i dont know much about 420as.. but tell me one thing, do zou have a gm style 3 wire map sensor? if so, how about wireing in a gm 3bar map sensor? or better yet.. take a hand pump and simulate boost on a stock mapsensor..and use a voltmeter to read its voltage ( also simulate vacuum and noter the readings..) then try the same with a gm 3 bar mapsensor and compare the readings..

or use one of those SMC mapsensor controllers..

is anyone up to this? i dont have a 420 but i would still like to know


edit: just searched google..no usefull results for a map sensor controller..does anyone remember these things?i read about em somewhere,just cant remember where.

 

[DSMcrazy3]

What? 95's and some 96's don't need any modification to the map sensor to bypass the extra pressure boost creates. Later models use missing link of FCD(fuel cut defender) to compensate for the extra pressure by fooling the ECU.

Josh