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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: Conny8412 on April 11, 2012, 11:01:26 am
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Hey guys, couple questions/concerns i have. Im running into some issues with my 87 1/2 ton on startup. Maybe you guys can give me some pointers...
I pump 1-2 times prior to turning key over, itll turn over and start up but i literally have to keep my foot on the gas for a good 5 minutes idling at about 1000-1100 RPM's before its "warmed up" enough to throw it into drive. If i let off the gas even a little during that 5 minute warmup time itll stall almost instantly. Even at red lights it drops so low almost stalling. Once it idles on its own, i feel as if it sits a little low almost around 600RPM and when in reverse at anytime it drops real low almost to the point where it can stall out anytime i throw it into reverse. Things ive noticed that may cause an issue:
-Braided fuel line from fuel cell to engine bay smells heavily of gas. Could it possibly be losing pressure?
-Electric choke has not been installed yet. Maybe this would help?
-Does Timing/tuning need to be done in order to create a higher idle and/or keep it from droppin to a stall?
Any info/thoughts would be great because im sort of at a loss. Im running a 400 small block bored out to 406. 850 Demon Carb. Roller Rockers. Thanks in advance
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No choke is your biggest issue; once installed and adjusted your cold-start symptoms should go away. Smelling raw fuel from a hose signifies a leak - is dangerous - and should be given priority. Once the fuel leak is corrected, set the timing and then the idle with the engine up to normal operating temperature.
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No choke is your biggest issue; once installed and adjusted your cold-start symptoms should go away. Smelling raw fuel from a hose signifies a leak - is dangerous - and should be given priority. Once the fuel leak is corrected, set the timing and then the idle with the engine up to normal operating temperature.
I agree with this but just wanted to add to it. Once you have the choke, fuel leak, timing, and idle set so it runs good fine tune the air/fuel ratio with a vacuum gauge then readjust the idle.
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No choke is your biggest issue; once installed and adjusted your cold-start symptoms should go away. Smelling raw fuel from a hose signifies a leak - is dangerous - and should be given priority. Once the fuel leak is corrected, set the timing and then the idle with the engine up to normal operating temperature.
I agree with this but just wanted to add to it. Once you have the choke, fuel leak, timing, and idle set so it runs good fine tune the air/fuel ratio with a vacuum gauge then readjust the idle.
I am third to these steps, electric choke is main, setting rpm will solve the issue you have after it is warm and sitting at light like you described, the other steps are just as important, and even safety issues. Would hate to hear that your truck burned down from a gas leak.
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We forgot to mention to check the float level too.
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Thanks for all the help. Keep it coming if anyone else has more ideas as well. Thanks guys.