Hesitation after engine Warms up

[shields]

Well it turned out that the 1990 Mustang O2 sensor I had put on my BMW was not electrically compatible and was throwing everything off. What a waste of money!

Whatever you do, Do not use the Mustang sensor.

[DSchultz325e]

Where'd you get the recommendation to use that? I'd heard of the 5.0 injectors but not that.

[jtuner]

So all of this and could just be an O2 sensor?? I haven't changed it yet, but I didn't think that it would do this to the motor... Lemme know, cuz I don't know if this thing is fixed yet....
I looked in to the pulse sensor, is this the same thing as the reference sensor? The thing that connects to the transmission along with the speed reference sensor? Thanks..

[shields]

For me, the problem turned out to be the O2 sensor. disconnect the plug and drive around and see. It'll idle crappy, but the hesitation should go away.
and DON't use the Mustang O2 sensor!.
It fits, but it'll throw the computer off as it is not electrically compatible.

good luck.

[jtuner]

cool, i'm about to go change it out right now.. I swapped out that FPR thats near the secondary pump and it didn't do anything..
I'll keep you updated how it goes.. thanks for helpin!!

[shields]

Did you replace it?
and if so, any difference??

[jtuner]

yup replaced it.. I think it's the fuel filter tho, not an FPR.. anyhoo, I worked ALL day on it yesterday.. Unplugged the O2 sensor, changed the transfer pump, changed the main fuel pump.. I also changed the cold start valve... nothing helps... I'm thinking maybe it in the distributor, in which I don't have the tools to get the fan shroud off, or the open end 8mm to get the actual 'trib off.. SO, I'm having it plugged in to a machine today, and we'll see what happens..
The weird shit is, every once in a blue moon I'll start it up and drive it around, and there's not a sputter spit or anything,, it drives flawless.. I made an hour and half trip with it without a problem.. Soon as I turned it back on to drive back, as soon as I hit the gas, hesitation, sputter, pop, spit... God only knows what wrong with this damn thing, but I feel I've done everything in MY power to fix it.. Now I guess I'll put it in the hands of a professional Thanks for yer help tho.. how's your car running now with the new O2 sensor??

[nando]

Where'd you get the recommendation to use that? I'd heard of the 5.0 injectors but not that.

but like dood it's like $25 cheaper! that's like 2 weeks worth of allowance! ;)