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  • 82 CFI starts to sputter at around 2Krpm
  • 82 CFI starts to sputter at around 2Krpm
  • 82 CFI starts to sputter at around 2Krpm
  • 82 CFI starts to sputter at around 2Krpm

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  1. #1
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    Default 82 CFI starts to sputter at around 2Krpm

    My 82 seemed to be running great until I decided to fix the cruise. Now I cannot get it to run correctly. Only thing I did was disconnect hoses from the canister on the side that goes to the PVC and tank vent. Think I have everything hook back up correctly now.
    My problem now is that once I try to drive the car acts like the fuel is being shut off at around 2K rpm (not every time though) and I have to pump the throttle to keep it running. Spits and sputters until I get enough fuel back to keep it running. I disconnected the vacuum line that went to the cruise and have it plugged off now (no change). Have checked the other vacuum lines and they seem to all be ok. Have plugged the vacuum line to the headlight and interior temp control (no change). Car seems to idle a little higher than normal now and also surges every once in awhile at idle.

    Fuel filter was changed about two years ago and also have an 85 pump installed. Have not measured the fuel pressure but it was around 14psi the list time I checked. Will look into this once I find my pressure gauge. Have sprayed carb cleaner around the manifold lid and don't seem to have a leak.

    Any thoughts on what else I should look at. I hate when you try to fix one thing and create another problem. Car ran great before I messed with the cruise, just came back from a 200 mile trip the weekend before.

  2. #2
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    Double check your vacuum lines, it may seem minor but having one in the wrong place can make a big difference. (Even where it connects to the canister)
    check the fuel pressure.
    or i could be way off, problem may be totally unrelated to what you have done.

  3. #3
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    Trying to find a diagram that shows how to connect the vacuum system back to the canister. Think I have it correctly but need to verify. Currently have the headlight and cruise vacuum disconnected so this is not impacting it.

    Checked the fuel pressure and started off at 11.5 psi(was around 13 the last time I checked). What seems to be happening is that suddenly it starts to dump a lot of fuel. Pressure will drop a pound or so and keep sputting excessive fuel until the car stops. Start it back up and fuel pressure has drop. Each time fuel pressure drops after each killed engine. Finally went to about 9 psi.

    Tried to adjust the fuel pressure up and could not get it to go up. Pulled the TB regulator off and the spring is compressed all the way it can go. Which way is the spring supposed to go in order to adjust the pressure?
    Last edited by Shawnee; 06-08-14 at 05:46 PM.

  4. #4
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    Quote Originally Posted by Shawnee View Post
    Trying to find a diagram that shows how to connect the vacuum system back to the canister. Think I have it correctly but need to verify. Currently have the headlight and cruise vacuum disconnected so this is not impacting it.
    There should be a decal under the hood with a diagram on it. As well as some other info. If it's not there replacements are available.

  5. #5
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    Quote Originally Posted by Shawnee View Post
    Trying to find a diagram that shows how to connect the vacuum system back to the canister. Think I have it correctly but need to verify. Currently have the headlight and cruise vacuum disconnected so this is not impacting it.

    Checked the fuel pressure and started off at 11.5 psi(was around 13 the last time I checked). What seems to be happening is that suddenly it starts to dump a lot of fuel. Pressure will drop a pound or so and keep sputting excessive fuel until the car stops. Start it back up and fuel pressure has drop. Each time fuel pressure drops after each killed engine. Finally went to about 9 psi.

    Tried to adjust the fuel pressure up and could not get it to go up. Pulled the TB regulator off and the spring is compressed all the way it can go. Which way is the spring supposed to go in order to adjust the pressure?
    If pressure is an issue... the problem could be either the pump or the regulator.

    You need to check the pressure between the TBs to determine what your actual pressure is. To do this, you'll need to run a line with a gauge that sits between the two TBs (this is the line that uses the outlet side of the front TB and the inlet side of the rear TB). You should have between 12-13 psi if I remember correctly.

    If it were me... I'd buy a regulator kit and install the new diaphragm. A while back, the orange rubber on mine was white when I replaced it. Yeah, it was very old!

    If you replace the diaphragm- and it still doesn't hold pressure- your pump is likely bad. TBI motors are finicky about fuel pressure and when they don't use a vacuum referenced regulator (the crossfire did not use one), they can be even more finicky.

    Hope that helps!!
    1982 Dark Blue Corvette
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    1995 Trans Am
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    1982 Chevrolet Corvette , 350 2k RPM Stall Converter + Updgraded Transmission + Governor Set For 5,450rpm Shifts 3.73 Code 42 Dark Mettalic Blue with a twist

  6. #6
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    Checked the pressure between the TB's using the method mentioned above. That is how I got the numbers listed in my earlier post. Have started to look at the regulator as the pump is only about a year old.

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    Finally got back to working on this again. Checked the pressure before the front TB and also at the filter area (gage installed instead of filter) and only getting about 7-8 psi while running of prime. I would assume this should be a lot higher since I have an 85 pump installed. Sounds like my pump is going bad or I have some type of blockage between the tank and the filter. It is only about 1-1/2 years old and less than 1,000 miles.

    Static voltage at the FP fuse and FP connector is 12v. Have not checked while the car is running

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