Today I was Scanning all the Data while driving like I've been doing the last few days and all at once the car started running rich and the BLM whent to 108.
When I stopped I smelt raw fuel, I removed the gas cap and lots of air keep coming out didn't whant to stop also I found that the fuel pressure regulator is makeing a hammerring noise.
Is my fuel pressure reg. failing or is there a problem with the canister purge system.
What do you guys think.
Thanks guys for any help

Note: my fuel pressure is set at 45psi
my mods are in my sig.

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Louis
Convertable
92 Z28 305tpi Auto
1/4 at 13.23 @ 106.1mph w/Paxton 10psi, Ram air mod,Water methanol inj.,52mm T/B,ASM Large tube runners, ported upper & lower intakes,AFPR,23# injectors,1.6 roller rockers,slp tri-y headers,3in. cat,3in. gale banks cat back system,3.42 gears,17x9 camaro SS wheels, 285x40x17 tires,and much more.
http://www.lbsz28blown.cz28.com

 

After further investigation and reviewing the data I recorded I found that the BLM was driving down to 108 when the canister purge solenoid was commanded open.
Apparently the fuel in north texas during the winter has a lower vapor pressure for winter operation and will be phased out in the comming month.
As this fuel is heated by high O.A.T. above 80deg F, return fuel and the exhaust there is lots of vapoer released which presserizes the tank and makes its way to the T/B via the canister purge system.
So to prove this theroy I removed the gas cap and drove the car and the BLM's where back to 128 / 126.
Has anybody else see this.

------------------
Louis
Convertable
92 Z28 305tpi Auto
1/4 at 13.23 @ 106.1mph w/Paxton 10psi, Ram air mod,Water methanol inj.,52mm T/B,ASM Large tube runners, ported upper & lower intakes,AFPR,23# injectors,1.6 roller rockers,slp tri-y headers,3in. cat,3in. gale banks cat back system,3.42 gears,17x9 camaro SS wheels, 285x40x17 tires,and much more.
http://www.lbsz28blown.cz28.com

 

I have seen something similar. I have seen the canister purge solenoid get plugged or malfunction and not allow the fuel tank to vent at all. This causes the fuel tank to have a vacuum created in it from the tank not getting any air into it to replace the space that is used up when the fuel is consumed and the pressure build up that you described, during hot days form the fuel vapor. They both usually cause a subtle, hollow, metallic 'bang' that can be heard after driving the car or when it is really hot out, and the car is parked with the engine off. The noise is the tank popping back into shape as the fuel vapors cool down after driving or as the vacuum dissapates inside the tank. I understand that a one-way vent is installed near the tank and that this valve is supposed to let air into the tank to prevent the vaccum condition but not allow venting into the atmosphere. I also understand that this valve is often INOP.

Both of the conditions can be remedied by installing the EVAP canister and its related components into the trash can and letting the fuel tank vent directly into the atmosphere. While this practice is not endorsed by the EPA or any other environmentalist-type associations, it is VERY FREE.


note: Gone untreated, these conditions WILL destroy the in-tank fuel pump due to the dramatic increase in the workload required by the pump to move the fuel out of a vacuumized(sp) or pressurized environment.

Those are my takes on what is going on. hope that is some help for ya.

Laterzzzzzzzzz