Missing Problems
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Joined: May 2008
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From: Roanoke Rapids NC
Missing Problems
Hi everyone...
I have a 85 vett stock....and I am haveing a missing problem....Where to start??? ok lets start--when I am driving around town in 2nd gear(automatic) and when the rpm's reach around 2,000 you can feel a major miss in the motor. With out moving the gas pedel you feel the miss come and go....and when it shifts into 3rd it will run slugish........I have put a new EGR valve, ECM, plugs, wires, re-set the timing,throttle sensor,control valve, and check the fuel injectors. I do have one injector putting out 8 to 10 ohms.. the rest are putting out 12ohms... Thanks for any suggestions......Bo
I have a 85 vett stock....and I am haveing a missing problem....Where to start??? ok lets start--when I am driving around town in 2nd gear(automatic) and when the rpm's reach around 2,000 you can feel a major miss in the motor. With out moving the gas pedel you feel the miss come and go....and when it shifts into 3rd it will run slugish........I have put a new EGR valve, ECM, plugs, wires, re-set the timing,throttle sensor,control valve, and check the fuel injectors. I do have one injector putting out 8 to 10 ohms.. the rest are putting out 12ohms... Thanks for any suggestions......Bo
Racer
Joined: Sep 2010
Posts: 305
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From: Epfenbach BW
Did you check the fuel pressure?
Otherwise a new set of Injectors would not be that bad of an idea anyway. Your Ohm readings suggest a faulty injector, but the ohm-test is not a 100 proof of working or bad injectors.
Somehow sounds like a fuel problem to me.
But I would check for proper spark though....
Otherwise a new set of Injectors would not be that bad of an idea anyway. Your Ohm readings suggest a faulty injector, but the ohm-test is not a 100 proof of working or bad injectors.
Somehow sounds like a fuel problem to me.
But I would check for proper spark though....
Racer
Joined: Apr 2011
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From: Tipp City Ohio
Le Mans Master
Joined: Sep 2006
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From: Phoenix AZ
2021 C4 of the Year - Modified Finalist
maybe you should have spent more than $300 and got one that runs.
Seriously, you need to change injectors, check fuel pressure, filter, and buy a new fuel pressure regulator diaphragm.
put a fuel pressure gauge on it, and see what the pressure is. pull off the vacuum hose from the regulator, and it should jump up 5 LBS.
If it doesn't, it's the diaphragm.
If you are running 26 year old injectors with today's gasoline, you should expect these kinds of problems.
The new fuel blend packages ruin the old injectors, soften old fuel hose, eat certain plastics and the gas goes stale and turns to jelly after a while.
Seriously, you need to change injectors, check fuel pressure, filter, and buy a new fuel pressure regulator diaphragm.
put a fuel pressure gauge on it, and see what the pressure is. pull off the vacuum hose from the regulator, and it should jump up 5 LBS.
If it doesn't, it's the diaphragm.
If you are running 26 year old injectors with today's gasoline, you should expect these kinds of problems.
The new fuel blend packages ruin the old injectors, soften old fuel hose, eat certain plastics and the gas goes stale and turns to jelly after a while.
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Joined: May 2008
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From: Roanoke Rapids NC
Coupeguy, I tried the fuel Pressure and it started at 43lbs before starting and at idle speed and at 2000 rpm it drop to 37lbs....pull the vacume line and no change....so I will start there...thanks bo
P.S. I won the car on a raffle 4 years ago and I have had no problems until now...The motor was rebuilt 6 years ago according to the previous owner..... But thanks again for all the info......bo
P.S. I won the car on a raffle 4 years ago and I have had no problems until now...The motor was rebuilt 6 years ago according to the previous owner..... But thanks again for all the info......bo
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Thread Starter
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Joined: May 2008
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From: Roanoke Rapids NC
4th Gear
Joined: May 2010
Posts: 4
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From: Phoenix Arizona
Had the same issues. Took out the plugs (Bosch Plat2- POS plugs) and noticed a build up of carbon/oil on a few. Put new Delco plugs in for the cast iron heads and it drives like it should now. Give it a check.
Burning Brakes
Joined: Jun 2003
Posts: 1,079
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From: Niagara Falls ON
Agreed. Change the distributor cap and rotor. While it is off look at the condition inside to make sure that everything looks good (no broken plastic parts, wires look good, etc.) Look inside the old cap to check condition. If you see anything report back and someone will tell you what it means. (corrosion, carbon tracking, etc.)
Check the plugs as someone has mentioned. You said that you replaced them but have a look at the new ones to see what they look like. Oily, dirty, etc.)
Good luck.
Check the plugs as someone has mentioned. You said that you replaced them but have a look at the new ones to see what they look like. Oily, dirty, etc.)
Good luck.
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Joined: May 2008
Posts: 72
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From: Roanoke Rapids NC
Agreed. Change the distributor cap and rotor. While it is off look at the condition inside to make sure that everything looks good (no broken plastic parts, wires look good, etc.) Look inside the old cap to check condition. If you see anything report back and someone will tell you what it means. (corrosion, carbon tracking, etc.)
Check the plugs as someone has mentioned. You said that you replaced them but have a look at the new ones to see what they look like. Oily, dirty, etc.)
Good luck.
Check the plugs as someone has mentioned. You said that you replaced them but have a look at the new ones to see what they look like. Oily, dirty, etc.)
Good luck.
Drifting
Joined: Feb 2006
Posts: 1,423
Likes: 96
From: Magnolia Tx
Coupeguy, I tried the fuel Pressure and it started at 43lbs before starting and at idle speed and at 2000 rpm it drop to 37lbs....pull the vacume line and no change....so I will start there...thanks bo
P.S. I won the car on a raffle 4 years ago and I have had no problems until now...The motor was rebuilt 6 years ago according to the previous owner..... But thanks again for all the info......bo
P.S. I won the car on a raffle 4 years ago and I have had no problems until now...The motor was rebuilt 6 years ago according to the previous owner..... But thanks again for all the info......bo
the car than revving in the driveway.
Coupeguy is right, check the regulator before you pull the pump.
Last edited by Benny42; May 28, 2011 at 01:34 PM.
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Joined: May 2008
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From: Roanoke Rapids NC
Last edited by $300vett; May 29, 2011 at 06:24 PM.