heres what i got.

1986 transam
350 with lopey cam
#19 injectors
custom chip
dual exhaust
hooker headers
super coil
other little mods.

What pressure should I be around?
Also, the car bogs and sometimes dies when i floor it. Is the pressure to high or low.

Thanks

 

GS,

The problem might be as much with your PROM and injectors as the fuel pressure. If the "custom chip" fuel and spark tables were not written for the cam, the fuel delivery might be incorrect. Additionally, 19lb/hr injectors are sized more appropriately for a 305 CID engine's power requirements at WOT. Increasing the fuel pressure might enrich your WOT mixture enough to be satisfactory, but will likely push the fuel tables to a very low count under "normal" driving conditions.

You could try running at about 48PSIG, but should really find a set of 22 or 24 lb/hr injectors for your 350, and lean toward the 24s if the cam and intake/exhaust are significantly better than the stock items.

------------------
Later,
Vader
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"I cannot take this any more... Saying everything I've said before..."
Adobe Acrobat Reader 4.0

[This message has been edited by Vader (edited January 10, 2001).]

 

the chip is custom from TPIS and they programmed it for the #19 injectors, cam, etc. I actually bought the injectors from TPIS too. So the chip is properly coded for everything, cam, etc.

 

GS,

It's not uncommon to be lean at WOT for even a 305 on stock injectors at 44PSI rails pressure (no vacuum).

You can try setting it to right around 50 PSIG, but any higher is unnecessarily hard on the fuel pump and might contribute to premature failure. If you have an aftermarket pump (like a Mallory or Walbro) that is capable of and designed for pressures up to 90 PSIG, you can try raising it to 55-60 or so.

It still seems to be a matching problem, even though TPIS sold you the injectors. There are a lot of 305s running on 24lb/hr injectors to avoid the lean operation at WOT. A 350 could only be straining more for fuel through the small orifaces.

------------------
Later,
Vader
------------------
"I cannot take this any more... Saying everything I've said before..."
Adobe Acrobat Reader 4.0

 

Thanks for the help..i'll try setting the pressure to 50psi. If that doesn't work i'll try seeing if i can get new injectors.