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Discussion Starter · #1 · (Edited)
HELP, car wont run or start

so today, i put in my SS clutch line and put the car back togather, now it misses really bad(and thats if it even starts).. the car will sometimes start, idle really low and shake and miss????????? the only thing i can think is that i had unhooked the mas air flow sensor but now it is hooked back up? will this cause it to run bad for a little while? please help..

ps(all i did was remove CAI, battery and tray and old rubber clutch line) and the car ran perfect before this..
 

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Make sure you didn't open any vacuum leaks anywhere. Also, make sure you didn't overtighten the connection to the VAF, which can cause serious driveability/idle issues.
-Garrett
 

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Discussion Starter · #3 ·
vaf meaning the airflow sensor??
 

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Discussion Starter · #4 · (Edited)
yeah so i checked for vac leeks, nothing... checked and cleaned all connections, nothing................ checked plugs and wires, nothing..... i think this is a mass air problem. what do i need to do?????????

also, the car has acted up like this before when unhooking the mass air(but never this bad) but, when you unhhok the mass air and reset the computer, shouldent that put the car back to factory settings and make it run good???? why is my car running like **** when any sensor is unhooked???? is there some sort of problem causing the computer to compensate and make it run better...???(b.c at normal factory settings it runs like crap)
 

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darren said:
yeah so i checked for vac leeks, nothing... checked and cleaned all connections, nothing................ checked plugs and wires, nothing..... i think this is a mass air problem. what do i need to do?????????

also, the car has acted up like this before when unhooking the mass air(but never this bad) but, when you unhhok the mass air and reset the computer, shouldent that put the car back to factory settings and make it run good???? why is my car running like **** when any sensor is unhooked???? is there some sort of problem causing the computer to compensate and make it run better...???(b.c at normal factory settings it runs like crap)
Did you look at that sensor.....its not a mass airflow sensor. Its a VAF, a Vane Air Flow meter. Its significantly cheaper to implement than a MAF, and also a bit more restrictive.

Anyhow, did you disconnect the (-)battery connection and hold the brake pedal to reset the ECU? If not, give it a shot.

Also, you did not mention whether or not you properly torqued the connections to the VAF. It is very easy to distort the housing, which will cause all sorts of problems.

Review:
-Its a VAF, not a mass air system.
-Make sure you havent distorted/cracked/overtorqued it. Sometimes it will go back to normal after reducing the clamping pressure.

-Garrett
 

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did you install it vertically and is the plunger able to move freely?
 

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Discussion Starter · #7 ·
plunger moves freely, reset computer, checked plugs and wires.. looked over the engine for the last hour looking for anything out of order and everything seems normal..except the idle.. idles at like 450 rpm's bumps like it has a madd set of cams and is at a big loss of power. if i free revv it at any rpm range, it misses like crazy. also, i have 2 A/f guages (frnt/rear banks). under idle, both jump up and down lean rich lean rich...and free reving they put out normal readings. but when VAF was unhooked at 3k frnt bank was madd rich and rear was all the way lean??? i dunno. but help is needed..
 

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darren said:
but when VAF was unhooked at 3k frnt bank was madd rich and rear was all the way lean??? i dunno. but help is needed..
Because the VAF is absolutely key to fueling decisions. Why is that hard to understand? It isnt supposed to run well without the VAF, it barely limps. You wouldn't like making fuel metering decisions without any airflow data either, would you? You would have to make an educated guess based on RPM and throttle angle, like the PCM does. It does a good enough job to make it run, but not well.

Did you check for codes?
-Garrett
 

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i think the VAF is still putting out an in range signal. the PCM doesnt have the diagnostic capability to realize that its an implausible signal, so its not going into FMEM.


disconnect the vaf and tell us how it runs...
 

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Discussion Starter · #10 ·
like crap
 

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Discussion Starter · #11 ·
so this morning i started the car, and it ran normal except for a 1100 idle... then as soon as it got hot, it started again, missing and everything else.. could this be a distributor problem???
 

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could be a CTS, could be an IAC, could be a vacuum leak, probably something to do with the VAF...
 

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Discussion Starter · #13 ·
i work at a mazda dealer and today i took it in.. first off the plug wires, they were very damaed and frayed where they hook into the disty, so i got new factory mazda(ngk) wires.. still happend.. ran it on the code machine and first code was 10, then 16, then 4.. i think 16 was egr, 10 was air temp sensor and we could not find code 4?? but they checked the egr to see if it was open(stuck) and it was not.. they reset the codes and ran the car again.. same problem.. but they pretty much narrowed it down to be either the iac, tps or VAF.. so tommorow i am going to swap parts with a buddy and see if/ what part it is or if it fixes it?
 

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Discussion Starter · #14 ·
this pos is pissing me off.. swaped out 3 different VAF sensors today and no difference... what the hell is going on with this car?
 
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