tire size Posted March 2, 2023 Share Posted March 2, 2023 i have a 1972 monte carlo with an after market 454 the serial numbers on the motor dates it between 1976-1978 and it seems to have stumped 2 mechanics. after a short warm up car will run perfect at 30- 40 mph any attempt to go faster motor will sputter and stall, also when floored no response at all, if i let off the gas it will return to normal. have a holly 4bl that has not been rebuilt, yet. gas in tank is new and has stabilizer added. any suggestions would be welcome. Quote Link to comment Share on other sites More sharing options...
Scott S. Posted March 2, 2023 Share Posted March 2, 2023 I'd check the filters.... There may be just enough of a clog that allows constant flow, but plugs during sudden increased flow. Quote Link to comment Share on other sites More sharing options...
1970mcss Posted March 2, 2023 Share Posted March 2, 2023 How about the advanced timing. My car basically did the same thing until I set the advanced timing. Good luck 3 Quote Link to comment Share on other sites More sharing options...
MC1of80 Posted March 2, 2023 Share Posted March 2, 2023 43 minutes ago, 1970mcss said: How about the advanced timing. My car basically did the same thing until I set the advanced timing. Good luck To add to what was said, make sure the weights in the distributor are free, not rusted or rotor preventing them to move. 2 Quote Link to comment Share on other sites More sharing options...
Mike Brichta Posted March 3, 2023 Share Posted March 3, 2023 If it has an HEI distributor, might be the distributor module. I've seen bad modules do some weird things. Good luck! Quote Link to comment Share on other sites More sharing options...
EVC Posted March 3, 2023 Share Posted March 3, 2023 1 hour ago, Mike Brichta said: If it has an HEI distributor, might be the distributor module. I've seen bad modules do some weird things. Good luck! Also, check the voltage to the HEI …. Must be 12 volts. Quote Link to comment Share on other sites More sharing options...
tire size Posted March 6, 2023 Author Share Posted March 6, 2023 On 3/2/2023 at 11:47 AM, tire size said: i have a 1972 monte carlo with an after market 454 the serial numbers on the motor dates it between 1976-1978 and it seems to have stumped 2 mechanics. after a short warm up car will run perfect at 30- 40 mph any attempt to go faster motor will sputter and stall, also when floored no response at all, if i let off the gas it will return to normal. have a holly 4bl that has not been rebuilt, yet. gas in tank is new and has stabilizer added. any suggestions would be welcome. thank you for the responses, fuel line was laying directly on the manifold that was fixed, vacuum line was left off carb, that was fixed better but still missing a bit when floored, distributor is next , then maybe new spark plug wires we shall see! Quote Link to comment Share on other sites More sharing options...
Grant MacPherson Posted March 6, 2023 Share Posted March 6, 2023 Long shot, if the car has been in storage for awhile check to see if exhaust is clear. Mice love to build nests there. Quote Link to comment Share on other sites More sharing options...
tire size Posted March 10, 2023 Author Share Posted March 10, 2023 On 3/6/2023 at 9:46 AM, tire size said: thank you for the responses, fuel line was laying directly on the manifold that was fixed, vacuum line was left off carb, that was fixed better but still missing a bit when floored, distributor is next , then maybe new spark plug wires we shall see! update it was a cracked distributor and split rotor runs perfect now up for sale! thanks for the help! Quote Link to comment Share on other sites More sharing options...
EVC Posted March 10, 2023 Share Posted March 10, 2023 3 hours ago, tire size said: update it was a cracked distributor and split rotor runs perfect now up for sale! thanks for the help! For future reference is your distributor the HEI or points style ? Quote Link to comment Share on other sites More sharing options...
tire size Posted March 10, 2023 Author Share Posted March 10, 2023 1 hour ago, EVC said: For future reference is your distributor the HEI or points style ? hei Quote Link to comment Share on other sites More sharing options...
cny first gen 71 Posted March 10, 2023 Share Posted March 10, 2023 5 hours ago, tire size said: update it was a cracked distributor and split rotor runs perfect now up for sale! thanks for the help! Was the distributor itself cracked or the cap? I've seen cracked caps and rotors but never a distributor? Just wondering 🤔 2 Quote Link to comment Share on other sites More sharing options...
Rob Peters Posted March 11, 2023 Share Posted March 11, 2023 5 hours ago, cny first gen 71 said: Was the distributor itself cracked or the cap? I've seen cracked caps and rotors but never a distributor? Just wondering 🤔 Good point Steve. rob 1 Quote Link to comment Share on other sites More sharing options...
tire size Posted March 11, 2023 Author Share Posted March 11, 2023 15 hours ago, Rob Peters said: Good point Steve. rob just the cap and rotor Quote Link to comment Share on other sites More sharing options...
EVC Posted March 11, 2023 Share Posted March 11, 2023 1 hour ago, tire size said: just the cap and rotor Stumped two mechanics… ? Interesting. A good mechanic would have looked inside the distributor thingy first. Quote Link to comment Share on other sites More sharing options...
Dtret Posted March 11, 2023 Share Posted March 11, 2023 None of us mentioned the cap and rotor either. I guess we all stink. Lol. I guess that’s what happens when we assume a “ mechanic “ checks the absolutely obvious things first. But don’t. So much for assuming. 2 Quote Link to comment Share on other sites More sharing options...
EVC Posted March 11, 2023 Share Posted March 11, 2023 2 minutes ago, Dtret said: None of us mentioned the cap and rotor either. I guess we all stink. Lol. I guess that’s what happens when we assume a “ mechanic “ checks the absolutely obvious things first. But don’t. So much for assuming. I agree,,, it would been much better to pull the engine , do a valve job and rebuild the carb… LOL Quote Link to comment Share on other sites More sharing options...
Dtret Posted March 11, 2023 Share Posted March 11, 2023 3 minutes ago, EVC said: I agree,,, it would been much better to pull the engine , do a valve job and rebuild the carb… LOL Change the transmission filter too. That will help. 1 Quote Link to comment Share on other sites More sharing options...
MC1of80 Posted March 11, 2023 Share Posted March 11, 2023 Idk about anyone else BUT I was taught that you check the cap and rotor as you take them off to check all or any other components in the distributor. This way if they are bad also the boss, service writer or myself could "upsell" the customer and prevent future issues or fix what they are complaining of. Don't you, meaning everyone who works on their own "stuff" check things as you disassemble them ? Just in case? 🤔 3 Quote Link to comment Share on other sites More sharing options...
tire size Posted March 11, 2023 Author Share Posted March 11, 2023 1 hour ago, EVC said: Stumped two mechanics… ? Interesting. A good mechanic would have looked inside the distributor thingy first. no, both thought it was fuel related, after digging the 2nd found and fixed the issue. i always try to stay positive and not judge people i dont know Quote Link to comment Share on other sites More sharing options...
Dtret Posted March 11, 2023 Share Posted March 11, 2023 23 minutes ago, MC1of80 said: Idk about anyone else BUT I was taught that you check the cap and rotor as you take them off to check all or any other components in the distributor. This way if they are bad also the boss, service writer or myself could "upsell" the customer and prevent future issues or fix what they are complaining of. Don't you, meaning everyone who works on their own "stuff" check things as you disassemble them ? Just in case? 🤔 Absolutely 100 percent. Quote Link to comment Share on other sites More sharing options...
EVC Posted March 11, 2023 Share Posted March 11, 2023 True story… Back in the early 90's , my son drove his vehicle to work one night and it rained… He got off work and it started misfiring badly… The tow truck driver took it to his shop of choice. They called my son and told him he needed a valve job… I went down to the shop and flipped the distributor cap off and without looking I asked the mechanic what he saw…. He said moisture and some carbon trailing…. …. After a little air blast and a Qtip to clear the condensation,,he was on his way…… I later did a compression check and all cylinders were within acceptable standards. He still drives the little 85 Bronco2… It's now his version of our classic Montes…. Lesson to my son was "valves don't burn while the car is parked". Quote Link to comment Share on other sites More sharing options...
EVC Posted March 11, 2023 Share Posted March 11, 2023 On 3/11/2023 at 1:07 PM, tire size said: no, both thought it was fuel related, after digging the 2nd found and fixed the issue. i always try to stay positive and not judge people i dont know Bruce,,, No harm or criticism meant… Most of us here struggle to repair our toys and we learn from each other …. I'd much rather fix it and use the knowledge of the many members here who probably have made the same common mistakes over the years….. The biggest mistakes I've made is paying someone to make mistakes and break my toys…. You're invited to join us … Best $25 bucks you'll ever spend… BTW… I was born and raised In Jacksonville way back in 1941….. You guys have a great Governor…. Quote Link to comment Share on other sites More sharing options...
EVC Posted March 12, 2023 Share Posted March 12, 2023 7 hours ago, Dtret said: Change the transmission filter too. That will help. you forgot paint the engine… Quote Link to comment Share on other sites More sharing options...
tire size Posted March 12, 2023 Author Share Posted March 12, 2023 23 hours ago, EVC said: Bruce,,, No harm or criticism meant… Most of us here struggle to repair our toys and we learn from each other …. I'd much rather fix it and use the knowledge of the many members here who probably have made the same common mistakes over the years….. The biggest mistakes I've made is paying someone to make mistakes and break my toys…. You're invited to join us … Best $25 bucks you'll ever spend… BTW… I was born and raised In Jacksonville way back in 1941….. You guys have a great Governor…. Ed C Ret USAF Senior Master Sgt… 1981…. Retired business man 2005. none taken, i guess i did not expect to spend as much as i have. first guy that looked at it was stuck on fuel wanted to rebuild the carb at 4-500 and i still would have had the same problem. i appreciate the invite but am selling the monte and moving on. guess me and old cars were not meant to be!! Quote Link to comment Share on other sites More sharing options...
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