looking for adjustable fuel pressure regulator

Dynoed my red car the other day (1993 1.6 normally aspirated) and according to the air-fuel ratio meter, it seems pretty lean.

Guy at the dyno place tried to sell me an adjustable fuel pressure regulator, but it used barb type fittings for the hoses and would need to be engineered to mount, so I didn’t get it.

Anyone know of an adjustable fuel pressure regulator designed to actually fit a Miata?

I looked on Track Dog and Flyin Miata sites and didn’t see anything that looked like it wouldn’t require some figuring to mount and was in the price range I had in mind (less than $150).

First, are you sure it is really running lean? The tail pipe sniffers used at dyno shops will often read lean because they are after the CAT.

If your stock 1.6 really is running lean, then something is wrong... adding an AFPR will only mask the true problem. I would start by checking the actual fuel pressures to see if you have an issue with the fuel pump, filter or the stock fuel pressure regulator.

I'm not sure it is lean -- the wiring associated with all the dyno hookups was a mess, and I'm not confident it was right

my car does not have a cat on it presently, so the readings aren't confused by having a cat in the system

I'm going to take the car to another dyno in Austin where they specialize in working on Miatas, and if lean, will have them check the fuel pressure

but want to source an adjustable unit in case that is the recommended fix

I know lots of shops tune with those when lean is present

A second dyno sounds like a good plan. I would be very surprised to hear it really was lean, as most non-boosted Miatas tend to run too rich. Another option to the AFPR would be the PowerCard TC2. It allows you to add fuel by increasing the injector pulse width where you tell it to. Locally, Gary at TrackDog Racing sells it and has experience installing and tuning it. He even has access to a dyno in Garland.

I was surprised to see lean across the board, but have to find out if it was right or not before I run another track session

I've been talking to Gary about various control devices, but he hasn't responded to a couple of inquiries, I guess because I hear he's on vacation

I used the same dyno Gary uses in Garland

when I go to sell the car, if it isn't Spec Miata legal, it will limit who I sell to and/or require a buyer to undo stuff

so may just go the tweak the AFM route if it proves to be needed

I have an AFPR in my bin of Miata parts. It's for sale at the right price.

[QUOTE=nealb;120310]

I've been talking to Gary about various control devices, but he hasn't responded to a couple of inquiries, I guess because I hear he's on vacation

Yes, he's on vacation.

Quote:

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Originally Posted by nealb

I've been talking to Gary about various control devices, but he hasn't responded to a couple of inquiries, I guess because I hear he's on vacation

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Neal,
Gary has been having problems checking his email while on vacation. He'll be back next monday. ;)

If you have a stock A/F meter you want to adjust that, not fuel pressure. Pop off the lid and loosen the clockspring to richen. More sophisticated adjustment is possible, but you probably want to run WBO2 at all times to get trickier.