Idk if this is the correct sub. Sorry mods if it isn't.
I have a 92 NA6 with a Voodoo turbo from FM.

Basically my problem is that when I'm in boost my air fuel ratio meter is saying 10-11 which is great. But then it rises to 14+ which is very lean during boost.

I have doused it in brake cleaner trying to find a vacuum leak. There is no misfire, but I changed plugs/wires/coilpack. I rechecked my tune on the Voodoobox. I changed the 02 sensor (not that it matters, Voodoo takes over once in boost), and I changed the airflow meter. I've also done fuel pressure tests and fuel pump is strong. Changed injectors (stock to stock).

I have a suspicion that the air flow meter doesn't like being upside down, but I haven't tried putting it right side up cause that's FM's way of configuring it for the turbo. But I haven't had those issues before. I've tried the AFM from my other car to compare and it does the same thing.

Again, I will have perfect air fuel until about 3 seconds into the pull and it'll lean out. Boost pressure where its suppose to be. No change in performance when it leans out either but it's obviously not a good thing to be leaning out during boost...

 

I'd contact FM on this. There were issues with some Voodoo boxes having the vacuum port leak, which would lead to the lean condition you are seeing... if the box isn't getting an accurate signal for vacuum/boost.

Not saying this IS the issue, but I'd reach out to them again if I were you.

 

Have you made sure youre not overboosting? That Voodoo box can only cope with very low boost, if its creeping beyond that you will quickly run out of fuel.

 

I've called them a couple of times but they have never mentioned this, does the board on the box itself have the vacuum leak or just the hose? I'll replace both now since I have it out anyways.

 

HEY, when I first put the turbo on it was making about 6PSI and now it's about 9PSI. My god. I will research on it, but is there a general reason a car would begin to overboost out of nowhere? I could very much see this as the culprit.

PS, if it is I'll buy you a beer!!!

 

Try disconnecting the wastegate actuator and see what kind of boost you can get (wrap it out to redline in 2nd or higher). You should be able to hit a coupe PSI, but that's about all.

 

Better idea: ditch the doo doo box and get a megasquirt.
sounds like youre just plum running out of fuel, get some big boy injectors while you're at it and stop playing with archaic technology.

 

Pretty sure the sensor has developed leaks in the past. It was either the Voodoo box or some other band-aid they sell that did this.

 

Thanks all! I totaled the car on the test drive. I'll be back on in a few months.