Well I did it and everything runs great. I put an aftermarket spring in it that allows you to tune to a higher range but my only problem is how do you tune your pressure...? I'm missing a step somewhere in the line of fuel pressure mods. Do I need to buy something or am I missing this "torque head screw" the spring instructions are talking about?

 

You don't......really unless your tuning your chip, there is NO reason to bother your fuel pressure. Your best bet is to get a fuel pressure guage for TBI, since the stock system doesn't have a pressure port, and set your new FPR to a stock 12 psi. Otherwise you're going to have problems. The old school way of thinking was to crank up the pressure and hope the ECM had enough self learning capablity to lean itself back out under part throttle. Since the ECM doesn't compensate during WOT your WOT would be richened up....the problem is most ECM's were rich from the factory. You really won't know what to do untill you data log and see what's really going on.

 

Alright. I didnt really plan on boosting it too much. I was only going to increase it a little because I am idling rough but I guess I should have asked if I should just up my idle a little. As far as when i do need to adjust where do I get a pressure port and what does it look like and cost

Curiosity killed the cat.

 

Your ruff idle is because of some other pre-existing problem. Shouldn't have to adjust your idle at all, the IAC and your ECM should have full control over your idle.

You can get a pressure port tap off of ebay and use a normal fuel pressure guage, or get a actron pressure guage that is designed for TBI, that comes with one of the adapters. Problem is that TBI specific guage won't work on normal FI engines.

 

I never had an idle problem before the VAPFR. Then again it only does it on cold start it jumps from 1000rpm down to 500rpm, then to 400rpm and sounds like it wants to stall. Then you can feel the computer kick in and bring it back up to 1000rpms

 

VAFPR on a stock engine will be a tremendous WASTE of fuel. at $3.10 ++ a gallon ? if you have mods that require a boatload of fuel on acceleration it might help but still wont run right without EBL and a proper tune. even with EBL i believe you need to know exactly FP idle and FP @ WOT.

i dont believe it has any affect at idle. you stated rich on idle B4 the vafpr on previous thread?