Maf Diff Between Map

Trying to find out some info. on the MAF sensor for a 1991 z28. Somewhere I've read that this year might not have one but use MAP instead. Any help? If anyone knows where I can find any diagrams on this thing please let me know.

it's got a map sensor

so there are no screens that can be removed, etc.?

nope. 90 and up went back to speed density (map). i wouldn't recommend it even if you did have a maf sensor because the thermal wire in the housing is very small and by removing the screen your let crap get in there. just touching it with ur finger can break it.

well i got another question for ya. id like to take my throttle body off and do some polishing, theres a gasket behind it that will probably rip off when i take it off (im assuming its old and needs replacement anyways). do i need to replace that gasket?

i would. there not very expensive, probly under $5

is there anything im gonna throw outta wack by removing the TB? i wanna do my polishing work and also bypass the TB so it runs cooler, im just worried that I'm gonna screw somethin up on this tpi system.

Why port and polish your throttle body? IMO it is just a waste of time. The ammount of air you will pass through is extremely marginal at best. Little stuff like that helps when you have nice flowing heads, cam, headers. Not on a stock setup. My buddy has a 02 z and we ported and polished his MAF and his TB and it did not show a damn thing different on the dyno.

well i guess im an optimistic. ive also seen dyno figures showing an increase, who knows.

well when it comes to TPI mods on the TB get an airfoil, or all that. you wont throw anything *out of whack* you should replace the gasket, its cheap so its worth it. youll spill coolant, but i think you knew this cuz your doing the TB bypass. or if you have some cash, go ahead and buy a aftermarket TB with 58mm bores and airfoil designed into the body, rather than a afterthought, personally i think it would be worth it, hit up jegs, i think they are like 300 bucks. not that bad, and worth the money IMO. unless polishing and porting are second nature to you.

thanks for the info guys

Why port and polish your throttle body? IMO it is just a waste of time. The ammount of air you will pass through is extremely marginal at best. Little stuff like that helps when you have nice flowing heads, cam, headers. Not on a stock setup. My buddy has a 02 z and we ported and polished his MAF and his TB and it did not show a damn thing different on the dyno.
BAAAD idea. the air flow wont change. in order to get a better flow through a TB you ned to port the manfold too. thats why you didnt see any difference. unless you port the intake on the manifold their will only be a bottle neck for the air.
also
Isnt map (manifold absolute pressure) and maf (mass air flow)???? both are needed for a fuel injected right?:sly:

it's always one or the other. tbi uses map while early tpi used maf, then they switched over to map on tpi in 1990. i think it's a cost issue more than anything, the maf usually always goes bad sometime in it's life, i think it's due to the burn off period after the car is shut down, think it wears it out. a mass air flow sensor can be more than $200 from a parts store while the map sensor is about $40

ok but my lt1 has both so thats why i was confused

it's very possible. i dont know too much about LT1's

yeah i just did alittle research and found it is one or the other for tbi and such. and LT1's and LS1's have nboth a maf and map

i have an 86 berlinetta which also has both the MAP and MAF sensor but i dont know where the MAP sensor is

i have an 86 berlinetta which also has both the MAP and MAF sensor but i dont know where the MAP sensor is



??? are you sure, my car has both a MAP and a MAF but the MAP is just for the stock boost gauge

yeah im sure it has both the MAF sensor is right by the dual air filters and the i was told that the MAP sensor is in the intake if true i would have to take the top half of the intake off i found a cheap place for turbos when i find the link again i'll post it

the MAF sensor, if you have one is in-line with the ducting that goes to the air filter from the throttle body. the MAP sensor is usually mounted on on the firewall underneath the vent cowl with a vacuum line running to the intake. on tpi it may be located under the plenum, but it's not actually "inside" the intake

my MAP sensor isn't on the firewall i looked theres no brackets or anything like that so i dont know where th fuck it is

if you have a MAF sensor, then you dont have a MAP sensor and vise versa. GM didn's use both untill the late 90's