MAF inquiry

[DrMaxwellEdison]

i have heard that the car should not run more than an idle and not for very long at that when the maf is not wired in circuit in a fuel injected car. i am having an issue with the car not firing when the maf in attached but running fine when disconnected. any suggestions? i am doing the brakes and such tomorrow, but would also like to address this issue tomorrow, also before I worry about the brakes, are the aspire axle splines any different from auto to manual? I have a manual festiva and a set of auto brake parts from an aspire, any ideas? I just put new Festiva axles in it, they haven't been more than twenty miles since new...

[nitrofarm]

Andrew Festy's dont have a MAF they have a VAF though. Maybe thats what you are talking about. But if its disconected it wont run. The fuel pump is in series with it. So I have know idea what you are refering to? You gotta be a little more clear ok. Maybe you are taling about the TPS your car could run at idle with that disconected I think.

[DrMaxwellEdison]

it's the VAF.... you're right, I have always been brought up to use them interchangeably, so I forgot the fact that it is indeed a VAF, which it is disconnected and the fuel pump is still pumping and the car will still run even with it disconnected

[econoaddict]

My VAF went bad, plugged in the car would not run, unplugged it would fire and idle but wouldn't run well if you tried to rev or drive it.
When it went bad my check engine light would not come on when you turned the car from off to run position if it was plugged in. Unplugged the light would work as it should.
Also no codes when it went bad.

[htchbck]

Not sure about the Vaf thingy I've never had one that would run with it unplugged at all but if that is the case then I'd say its a wiring problem somewhere else, not in the vaf itself if the engine will stay running longer than a few seconds with it unplugged. On the axles, the inboard (trans side) splines are different between auto and manual, but the outboard (hub) side is the same. If you have the auto Aspire brakes then you have the good upgrade (better than the manual aspire ones) and they will bolt up no problem to your brand new festiva axles

[DrMaxwellEdison]

Awesome Win for ME!!! YEAH!!!!
now to find some good 13inch wheels w/ the Aspire brake pattern, I'm thinking some Sears Dual patterns? possibly 14s

it runs rough without the VAF (obviously because the air isn't being metered) anyway I can make something to work?

[DrMaxwellEdison]

Before I rebuilt the engine it worked fine, but since I've put it back in at the begining of the week it has worked only when I unplug it and I believe I had to add a new ground to the Fuel pump before the rebuild because there was an issue getting it to work before

[Safety Guy]

Before I got Aqua on the road, I was swapping a B6 VAF back and forth between cars. Upon putting it back into Luxstiva, I started her up and tried to move: no go. She stalled out with any gas applied. I finally figured out that I hadn't connected the VAF plug. I was surprised that she started and ran at all without plugging in the VAF. As far as I know, Lux has never had any weird stuff done to her to allow this. She should be a stock auto other than her B6 and suspension swaps I did years ago.

Karl

[DrMaxwellEdison]

I'm still trying to figure out how to meter the air without trying to figure out why the VAF won't work when plugged in, the car runs without it, I replaced the fuel pump about 6 months ago in the car and had to add a ground since there was a problem with the pump not grounding (I'm not sure what it was/is) and I think when I did that that may have given the ability to run without the VAF, but this doesn't explain why it worked before I took the B3 out for the rebuild and it won't work now after putting the B3 back in after this rebuild.... nothing has changed as far as doing any new electrical, so this confuses me....

[nitrofarm]

I'm still trying to figure out how to meter the air without trying to figure out why the VAF won't work when plugged in, the car runs without it, I replaced the fuel pump about 6 months ago in the car and had to add a ground since there was a problem with the pump not grounding (I'm not sure what it was/is) and I think when I did that that may have given the ability to run without the VAF, but this doesn't explain why it worked before I took the B3 out for the rebuild and it won't work now after putting the B3 back in after this rebuild.... nothing has changed as far as doing any new electrical, so this confuses me....

Andrew you said your pump wasnt grounding. What I'm guessing happened is you replaced the pump & went to test it without the car running. ie turned the key on to look for power and got nothing? Then you said hey I have a bad ground? Anyway I'm not sure of the whys.... But I think you must have cut & spliced the GN/R wire at the FP relayto grd correct? If this is what happened then you must simply take this wire and connect back to where it was. NOW if the car still wont start.Check for continuity from this splice all the way back to to GN/R connection @ the VAF harness. If no power you have to find a cut in the wire. Basically the engineers didnt want the FP to run unless the VAF was "seeing" air flow. Now after fixing the splice you did before at the pump.And checking for continuity @ the VAF harness.If you DO have continuity @ the GN/R wire of the VAF harness. Plug it in & try to start the eng. If the FP wont come on. You found the problem. Its the FP switch in the VAF. Or possibly the whole VAF is full of green corrosion. With neg cable offthe batt. You can pull the cover off the VAF & take a peak. Or R&R VAF w/new. Hope all this rambling helps?

[kartracer46]

Thank you nitrofarm, I think he just needs a new VAF. That test will prove the issue wasn't with the pump. the wipers and connections in the VAF are most likely corroded and not making good contact anymore.

[nitrofarm]

Thank you nitrofarm, I think he just needs a new VAF. That test will prove the issue wasn't with the pump. the wipers and connections in the VAF are most likely corroded and not making good contact anymore.

But shouldnt he fix his splice. You dont want the pump to run with no VAF right?
Sounds like he made a Grd for the FP relay?

[nitrofarm]

Before I rebuilt the engine it worked fine, but since I've put it back in at the begining of the week it has worked only when I unplug it and I believe I had to add a new ground to the Fuel pump before the rebuild because there was an issue getting it to work before

After re-reading this maybe you bypassed the ground on the enertia switch? But you said you had issues before and it was FP Grd related. Thats all I was trying to figure out.

[kartracer46]

But shouldnt he fix his splice. You dont want the pump to run with no VAF right?
Sounds like he made a Grd for the FP relay?

I concour, the wiring should be returned to it's original state. It can be a dangerous situation if the fuel pump should continue to operate continuously.

[DrMaxwellEdison]

prior to my getting the car, it had not run for 8 years and I don't know about anything before that... I didn't disable the inertia switch, I know this because I popped the inertia switch in and out a couple of times to see if it had been bypassed... it had not...