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Topic: Fuel Pressure

in Forum: C3 Fuel, Emission Control, and Exhaust Systems


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Fuel Pressure (11/21)
 6/27/10 6:44pm
tb2k82ceLifetime Member
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Lemon Grove, CA - USA

Vette(s):
1982 C3 Collectors Edition 44000 miles, sat in the sun most of its life, My wife purchased it for me for Father's Day in 2007 from her girlfriend that had it for 19 years. It is on the road again. I'm retired but it is now my daily driver.


Joined: 10/17/2007
Posts: 2041

7.5 may not be enough but it is a lot better than 5.  Which is what I was getting.  You could hear the injectors sound softer like the spray was finer after the pump was replaced.  I also noticed that I could light up the tires from a stop now.  Before if you tried to jump that hard on it, it just ran out of fuel.  I will get it up to the correct pressure and balance the injectors.  I notice that while the idle is smoother now it also has a slight surge I figure that could be unbalance injectors maybe.  Again I stress it is only a slight surge.

Thoughts
Fuel Pressure (12/21)
 6/30/10 9:16pm
tb2k82ceLifetime Member
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Lemon Grove, CA - USA

Vette(s):
1982 C3 Collectors Edition 44000 miles, sat in the sun most of its life, My wife purchased it for me for Father's Day in 2007 from her girlfriend that had it for 19 years. It is on the road again. I'm retired but it is now my daily driver.


Joined: 10/17/2007
Posts: 2041

Last post did not appear to go through forgive me if this ends up a dup.  I want to know which rebuild kit to purchase the car only has 44K miles on it and the pressure reg is the only thing that seems not to be working correctly.  I will use the Eckers part numbers so you can see what I'm talking about.  I do not care where I purchase.  Throttle body Rebuild Kit (completes front and Rear Units) #46324 or the fuel Regulator kit (both front and rear) # 46325

Do I do both or just one ??
Fuel Pressure (13/21)
 6/30/10 10:34pm
DaveMLifetime Member
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Flanders, NJ - USA

Vette(s):
1982 Black, ZZ4, Hooker Side Pipes, 3.55 Rear, Rebuilt & upgraded 700R4, All new suspension, brakes, & new Charcoal interior.


Joined: 1/27/2004
Posts: 2552

Where are you measuring the fuel pressure? Measure it before the TB's to make sure you're getting more than the pressure you need. Then measure on the line between the TB's. The pressure regulator is in the first TB so the line to the second one is regulated. 7.5 lbs. is not enough, you need around 11-12, I can't remember the exact number.
Dave

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Dave's '82


   

Fuel Pressure (14/21)
 7/1/10 2:58am
tb2k82ceLifetime Member
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Lemon Grove, CA - USA

Vette(s):
1982 C3 Collectors Edition 44000 miles, sat in the sun most of its life, My wife purchased it for me for Father's Day in 2007 from her girlfriend that had it for 19 years. It is on the road again. I'm retired but it is now my daily driver.


Joined: 10/17/2007
Posts: 2041

I'm measuring the pressure between the TBI's I have the DCS pressure gauge system installed.  I do not have a fuel pressure gauge system that I can connect to the fuel line somewhere before the first TBI.  I did just replace the fuel pump with a new 85 fuel pump.  I figure that it is not likely that is bad.  I guess I could take it to someone and have it put on a lift and have the fuel pressure checked.  It would most likely cost less than buying a fuel gauge and connectors to tap into the line.  By the way what should the pressure be if measured prior to the first TBI?
Fuel Pressure (15/21)
 7/1/10 7:15am
crossfire1982
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Cramerton, NC - USA

Vette(s):
black 1982 coupe slate gray interior, 350 crossfire, 1985 fuel pump, Steeroids R&P conversion


Joined: 8/22/2006
Posts: 1094

The 85 pumps outputs a pretty high pressure, about about 40 psi from what Ive read, although Ive never actually measured my "before regulator" pressure.  If you an get to a lift you could "T" in a gauge before the fuel filter and see what the pump is putting out to give you an idea where the problem may be.  I agree with Dave, 7.5 is not enough for the car to run well.
Fuel Pressure (16/21)
 7/1/10 11:01am
DaveMLifetime Member
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Flanders, NJ - USA

Vette(s):
1982 Black, ZZ4, Hooker Side Pipes, 3.55 Rear, Rebuilt & upgraded 700R4, All new suspension, brakes, & new Charcoal interior.


Joined: 1/27/2004
Posts: 2552

THE '85 PUMP GIVES YOU AROUND 50 PSI. IF THERE IS A KINK OR A CLOG IT WOULD AFFECT THE VOLUME MUCH MORE THAN THE PRESSURE. THERE'S REALLY NOTHING TO GO WRONG WITH THE REGULATOR, EXCEPT THE SPRING AND IF IT FAILED YOU WOULD GET HIGH PRESSURE. UNLESS SOMEONE MESSED WITH THE SETTING BEFORE. YOU REALLY NEED TO REBUILD THOSE TB'S. I GOT REBUILD KITS FROM MY LOCAL CHEVY DEALER.
DAVE


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Dave's '82


   

Fuel Pressure (17/21)
 7/1/10 12:32pm
tb2k82ceLifetime Member
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Lemon Grove, CA - USA

Vette(s):
1982 C3 Collectors Edition 44000 miles, sat in the sun most of its life, My wife purchased it for me for Father's Day in 2007 from her girlfriend that had it for 19 years. It is on the road again. I'm retired but it is now my daily driver.


Joined: 10/17/2007
Posts: 2041

You said TB's so you are recommending doing both of them, correct?  

I will be going overseas for a couple of weeks so ordering them is not a big deal.  But if I decide to do it this weekend a Dealer may be a good source if they did not have to order it.  What do you think the chances of that are?  Never know until I ask I guess.

Fuel Pressure (18/21)
 7/1/10 3:16pm
DaveMLifetime Member
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Flanders, NJ - USA

Vette(s):
1982 Black, ZZ4, Hooker Side Pipes, 3.55 Rear, Rebuilt & upgraded 700R4, All new suspension, brakes, & new Charcoal interior.


Joined: 1/27/2004
Posts: 2552

Makes no sense to do one and not the other. My dealer had the kits in stock, but there were some addtional parts he had to order. Don't remember, it was about 6 years ago. If you have the '82 service manual, just follow that, it has good pictures and diagrams, I never did one before I did mine and it was not too hard, make sure you the injectors on the right side, they are different.

Good luck,
Dave


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Lifetime Member #116
Dave's '82


   

Fuel Pressure (19/21)
 7/2/10 12:27am
tb2k82ceLifetime Member
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Lemon Grove, CA - USA

Vette(s):
1982 C3 Collectors Edition 44000 miles, sat in the sun most of its life, My wife purchased it for me for Father's Day in 2007 from her girlfriend that had it for 19 years. It is on the road again. I'm retired but it is now my daily driver.


Joined: 10/17/2007
Posts: 2041

I rebuild the fuel regulator.  Now I'm running about 13 psi.  But have other issues. No big improvement over the 8psi.  It feels like the car pulses when it is at idle and when it accelerates.  It is hard to describe but the closes is pulsing.

I'm going to balance out the TB's this weekend and see if there is something else that I find wrong that I can fix. 


Fuel Pressure (20/21)
 7/13/10 10:49am
kwoody
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Tucson, AZ - USA

Vette(s):
1982 Black/Tan Leather Build Code C09E Bronze TTop CrossFire Fuel Injection L83 85 Fuel Pump Auto Axle 2.72 Firestone Firehawk Indy500


Joined: 7/11/2010
Posts: 415

I've had my 82 C3 for about 4 years.  It sat in a field next to a pond in New England for 3 years.  I drained the old gas. put in new gas and had some brake work done.  It was and now is a good driver.  After about a year, the idle went fast (1200 rpm) and the engine started surging during the first 5 mins after starting (cold).  I shipped the car to Arizona and the car would barely stay running.
Took it to a local, he replaced the intake manifold gasket and was able to get it to pass the emission test here in AZ.  I still had the high idle and surging.  I replaced the chassis fuel filter. No change.  I then replaced the fuel pump and the strainer/filter (in tank)  That fixed the sluggish and most of the surging problem. 
Before I left MA I had the AC serviced.  It worked well there.  Not Hot but removed the water out of the air.  Once here in AZ the AC just barely got cool.  Lots of 105-109` days out here.  I found that the system was over serviced.  I reduced the pressure in the system and recharged up to 55 psi.  That stopped the compressor for short cycling causing the surges. So until the next "thing" I'm a happy camper. Normal idle, acceleration and AC operation. 


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Nobody ever waves when I'm driving the Explorer.
K Woody
Fuel Pressure (21/21)
 7/13/10 12:59pm
DaveMLifetime Member
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Flanders, NJ - USA

Vette(s):
1982 Black, ZZ4, Hooker Side Pipes, 3.55 Rear, Rebuilt & upgraded 700R4, All new suspension, brakes, & new Charcoal interior.


Joined: 1/27/2004
Posts: 2552

Gilbert, try disconnecting the battery then re-connect. It will reset the computer (no codes), then drive around for awhile and see it helps. The pulsing is controlled by the computer. The temp. sensor may be bad, if the computer thinks the car is still cold you can have that problem. The temp. sensor is in the intake manifold, not the one in the drivers side head (for guage).
Never ends huh. Wits End
Dave


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Lifetime Member #116
Dave's '82


   

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