I know this sounds like a noob question, but I followed the fuel lines as far as I can, and I don't see anywhere to tap into them. Do they have a Schrader valve (like the valve stem on a tire) or do they use some other connector? This is for an '88 Trans Am.

 

TBI does not have a test port, you have to adapt into an existing line.

 

Unfortunately on our TBI setups we have no Schrader valve or something of the sort. The only way to see fuel pressure on TBI is to get an after market gauge & fitting for the tbi. Theres numerous setups search and you'll find alot about it!

 

Just remember the larger 3/8" line is the feed line- that's the one you want to take pressure readings off of. The smaller 5/16" is the return and it will show very little pressure (it just dumps the bypassed fuel back into the tank).

I've thought about drilling and tapping a small 1/8 NPT fitting into the inlet fitting where the feed line goes into the TB, but I've never tried it. Looks a little tight there, but I think it might be possible. Then you could hook up a gague any time you like, but remove and plug the hole when you don't. Would seem to be a lot less destructive that the "ghetto" method of cutting out a section of hardline so you install a place to screw in the gague line.

 

On TBI cars you can buy an adapter from autozone that fits between the softline and hard line it has a schrader valve on it which you can then attach a fuel pressure gauge.

 

P/N # please

 

I am not sure, but know I got mine from autozone. Think it came from a fuel pressure kit that read from 0-40psi where the tpi kit is 0-like100psi.

but will see if I can find it.

 

this is it IIRC

http://www.ebay.com/itm/TBI-Throttle-Body-Injection-Fuel-Pressure-Gauge-Adapter-/260732758647?pt=Motors_Car_Truck_Parts_Accessories&hash=item3cb4e22a77&vxp=mtr

 

look up autozone CP7817 and you will see the pressure gauge and same adapter as that ebay auction.

http://www.autozone.com/autozone/acc...er=232719_0_0_

please note I have nothing to do with that auction buy at your own risk.

 

I realize this is a very old thread...but just what I needed to find this adapter.
More noob questions though...the adapter goes on the fuel line just before the fuel filter is that right?

I think my fuel pump has died, car won't start, cranks fine but doesn't sound like it is getting any fuel.
Should the fuel pressure be present when the key is turned to on but not running?
Does the fuel pump activate for just a few seconds or will pressure remain?

Thanks for any insight.

Edited to add 1992 Firebird Formula TBI 305

 

The adapter goes behind the TB where the fuel line goes into it. Can be a bit of a pain to install.

Yes the pump should run when the key is turned on and before starting. Should run for acoupla seconds and build up pressure, then not run again until either the engine starts, or the key is cycled again. Pressure should remain for several hours after it's been built up. Pressure in a TBI system should be somewhere around 10 -12 psi.

A no-start in a TBI car is SOOOOOOOOPER EEEEEEEZZZZZZZY to identify. If you can pour an ounce or 2 of gas into the motor, or shoot some starting fluid in it if you have some of that, and it starts & runs for a few seconds then dies, then you have a fuel delivery problem. If it still doesn't start you probably have a spark problem. How eeeeeeeezzzzzzzy can it get?

 

Thank you will do!