looking for input (chevy content)
squishware
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looking for input (chevy content)
- Thread starter squishware
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Dons78CJ5
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Do you have a nonvented gas tank?
In order for this system to work you have to set up the fuel system as a non vented system.
I ran into a fuel delivery issue on a V8 swap on a 84 S10.
In order for this system to work you have to set up the fuel system as a non vented system.
I ran into a fuel delivery issue on a V8 swap on a 84 S10.
Torxhead
Always Off-Roading Jeeper
You could refer to one of the diagrams from one of the t.b.i. conversions made for the Jeep CJ. For my '86 with a t.b.i. kit it has lines to the fuel tank, canister purge, and purge signal.
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- '85 CJ-7, 258/4.2L 6cyl. Bought new in 1985. Full cage, Warn 8274 winch, Ford 9" rear, front/rear Detroit Lockers w/4:88 R&P. T-5 tranny and 4:1 t'case. 33X12.50-15 BFG/AT, MSD ign, on board air---
I suggest you go to a CARB/DMV referee station, and find out just what you need to pass our damn SMOG tests.
LG
LG
squishware
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I was on the referee site this morning and it said RE: engine swaps that all the emissions components need to transfer with the new engine. I am thinking I should have failed with the Jeep canister. My plan is to try it and if it doesn't work out I can add the external vacuum solenoid that was on some models of S10.
How is the tank vented besides the cap? (and the canister purge)
How is the tank vented besides the cap? (and the canister purge)
Torxhead
Always Off-Roading Jeeper
If you look in a repair manual or at the factory service manual at a hose diagram for the CJ charcoal canister, you will notice that there is a vent line that runs from the gas tank to the canister. There is a replaceable filter at the bottom of that canister and two check valves in that line. The CJ vented gas cap I don't believe works all that well either, and gets tested by the smog man. If you use an external fuel pump, the tank venting system has to work properly.
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- Springfield, Missouri-U.S.A. Earth
- Vehicle(s)
- '85 CJ-7, 258/4.2L 6cyl. Bought new in 1985. Full cage, Warn 8274 winch, Ford 9" rear, front/rear Detroit Lockers w/4:88 R&P. T-5 tranny and 4:1 t'case. 33X12.50-15 BFG/AT, MSD ign, on board air---
I strongly urge you to go to a referee station, and get the print out for what the state says you need.....
LG
squishware
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Mr. Grits I KNOW you are right. I did look up the fuel lines in the FSM. Two rollover valves are located on top of the tank and one line each comes off of them. Those two lines Y together and that is the line from the tank to the canister. This information is helping me to form my actual question.
Is the TBI port marked "D" on the schematic I posted open to atmosphere when the jeep is not running.
ANSWER: It is manifold vacuum but blocked by the throttle plate until acceleration thus delaying the vacuum (0 at idle). The point is that it is not airtight.
EDIT: The solenoid on the canister or external is there to maintain 2psi in the tank. Acording to the S10 forum deleting the solenoid kills fuel pumps prematurely as the 2psi pressure is what primes the pump in the tank.
I think the gas caps also keep 2 psi.
Is the TBI port marked "D" on the schematic I posted open to atmosphere when the jeep is not running.
ANSWER: It is manifold vacuum but blocked by the throttle plate until acceleration thus delaying the vacuum (0 at idle). The point is that it is not airtight.
EDIT: The solenoid on the canister or external is there to maintain 2psi in the tank. Acording to the S10 forum deleting the solenoid kills fuel pumps prematurely as the 2psi pressure is what primes the pump in the tank.
I think the gas caps also keep 2 psi.
Last edited:
squishware
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Closure: I called the referee station today they took my info and said they would call back in three days if not sooner. The referee called about 3 hours later. He said use the GM canister no problem and add the external vacuum solenoid even if they did not have it until after your model year. Seemed very cool, logical and helpful. I fear when the 4.3 dies a little less now and I will have a $20 external solenoid to change (someday) as thats the bit that goes bad. Plus I could carry a spare.