MAF unplugged=Torque-y ride..Plugged in...Slow..?

[chris kelvin]

I still cannot figure this one out. I have a 4.6l thunderbird, 1995.. About 8 months ago a check engine light came on, got her scanned..it was the maf sensor. I replaced the maf from a place i bought it off of online, an auto retailer site. After unhooking the battery, and installing the maf the light is gone..and the car ran like it used to.

Now here's the weird part, if i unhook the maf, it will ofcoarse throw an engine light. BUT, what's weird is that my car feels so much more torque-y. Like if i'm at a light, and punch it my head snaps back and i get out of the hole faster. With the maf in, normal etc, it's much less torque-y..so it seems, but i can swear it's like 15-20ft lbs stronger....it feels that dramatic.

Maybe i got a maf from a 3.8 v6 tbird and i don't even know it..? Is that possible, to put a maf from a smaller engine into a V8...and it would register the air thinking it was a v6 and not an 8..? The maf itself is clean, and functioning properly...my mechanic tested its voltage and he said his cpu/device said it is fine. He didn't have an answer really to why the engine runs stronger with the maf unplugged. Granted when the maf is unplugged the car runs alittle rough, but doesn't stall.

BTW my exhaust is louder and deeper without the maf plugged in (i have no mufflers). Why does the car run stronger..? I've read somewhere about fuel being pumped into the engine constant..wheras with the maf in, it doesn't constantly burn fuel. If i leave the maf unplugged, technically can this do harm to the engine..? Honestly i'd like to leave her unplugged...

 

[chris kelvin]

I've already read/posted on www.tccoa.com, most those guys just say LEAVE HER IN..end of story. But i just wanna know can i leave it unplugged...? Would anything really result from it unplugged like blown engine, fouled plugs, etc etc...thanks alot. I know gas mileage would suffer, but it's worth the extra boost in acceleration.

I love how the exhaust sounds, so much deeper under acceleration.

 

[triggz]

leave it on.

the car will be horribly out of tune and be filthy on the inside in a few months.

 

[chris kelvin]

Yeah but i think this is subjective. I've searched google, ask.com etc and it's a mixed bag of good and bad it seems.

For one the car goes into limp mode, or close loop (it may be open loop..forgot) and basically injects a set amount of fuel into the engine so the engine will not be starved of fuel....causing bad gas mileage, and a popping exhaust..... But i'm guessing more fuel=better, stronger spark...more power....? right..?

You'll read some cars stall, and wont even start...then you'll read some cars, like mine, have a power increase that's odd. I can't stress how much better my car accelerates from a stop with the maf unplugged..and an engine light on, if i jab the gas...i'm moving and my head snaps. With the maf plugged in, no engine light=normal, it will be sluggish.

Rather then torque, it feels like the car is 200lbs lighter with the maf unplugged, if you can get me on that. One other thing, the rpms drop MUCH more quickly under deceleration....which is good i believe..?

If anyone can give an explanationon what exactly will happen if the maf is left unplugged, please do. Lol..i'm sick of hearing just "it's bad..trust me"...lol..

 

[triggz]

Optimum performance/cleanness is 13:1 (12:1 for blower cars) at WOT and 14.7:1 at idle/cruise. By removing a vital part of the system to calculate the amount of fuel needed, you're screwing the whole tune of the car.

Be aware, the MAF is not what controls the amount of fuel your car gets alone. The O2 sensors are the other half. The MAF calculates the amount of air coming in, and the O2 sensors see what goes out.. The MAF plays its biggest role in determining spark advance.

Fuel does not equal power. OXYGEN equals power The more of it that is burned, the more pressure is made to force the piston back down. Fuel is just the catalyst to burn the oxygen.


I speculate why you feel more 'umph' is because without the MAF, the ECU is adding a lot more timing. It shouldnt be- I wouldnt think. But that sounds like the case. An increase in timing adds gobs of torque. Unfortunately, you're probably losing a lot more HP across the board and in the end actually slower.

 

[chris kelvin]

Thanks alot for that Triggz, i appreciate any help.

It's just that it is so tempting to just leave it unplugged. If you've ever driven a heavy car, like mine (just shy of 3850lbs without me) and you knew you can have alittle extra umph...it's hard to keep her "runnin right" when you know you could run her bad..and gain some torque....lol.

 

[chris kelvin]

Btw so more fuel..is rich..? or lean..? By doing that what happens, the engine gets dirty on the inside faster..like carbon deposits..?

 

[triggz]

Thanks alot for that Triggz, i appreciate any help.

It's just that it is so tempting to just leave it unplugged. If you've ever driven a heavy car, like mine (just shy of 3850lbs without me) and you knew you can have alittle extra umph...it's hard to keep her "runnin right" when you know you could run her bad..and gain some torque....lol.

Does this car have a distributor? If so, just crank up the timing!

 

[chris kelvin]

No it's got ignition coil packs to plugs etc..

 

[DBMSTNG]

you're car is probably running lean because it's not getting a signal from the MAF. the engine is getting more air than it thinks it is. also, the MAF is used to calculate engine load which determines the timing. the car is probably running way too much timing. driving the car without the maf is stupid. don't do it.