Problem with 76 302

[Naildriver111]

Bad news. Drive to work in the AM and she ran like a champ (75 degrees). Went to lunch she boggged down within 1 mile (95 degrees). Drove home in the PM (75 degrees) she ran like a champ. Does it sound like NAILDRIVER111 may be right with vapor lock???

I must have missed that 1 mile part, It wouldn't vapor lock within 1 mile unless your stuck on the freeway in LA during rush hour. Since you have already changed the module , I recomend adding a clear fuel filter close to the carb. the next time it happens, pop the hood and see if it has fuel in it, if it does, then its an electrical Gremlin.

 

[trailpsycho]

If nothing else, unplug all the connectors to your module and look at them and clean them if necessary. The first couple of years that I had my bronco, the plugs cheesed up (looked like cheese, but I didnt taste it) and would cause the system to fail--just like if the module dies--but after cleaning them it would fire right up. Perhaps, this is occurring, but I would still lean toward the module...if these check OK. I think they are only $20-25---might as well buy one as a back up anyway. I hope that you figure this out soon. Definitely, let us know what you come up with.

 

[leener6357]

Got around to changing coil this weekend. We've only driven a few times since but have made it a point to drive in heat. Seems to be MUCH better but....gasped and choked one time since without cutting off and cut off once. Heat here has been 100+ with 90% humidity. Still afraid to get too far from home with it right now. Plan to switch from steel fuel line to rubber this evening and add the clear filter. The one time it cut off was leaving the gas station after refilling. Could be stirring up rust or trash???

 

[mtkawboy]

One way to check the module is to wire a bag of ice on it when it quits. You can usually drive them home after they cool down for a bit. The electronic pickups in the distributer sometimes go bad too. Id change them both if it isnt the vented cap issue. As for the vapor lock, try it with the hood off and see what it does. I cant picture vapor lock just driving a few blocks myself, Id go for the module

 

[77BroncoWag]

Bad news. Drive to work in the AM and she ran like a champ (75 degrees). Went to lunch she boggged down within 1 mile (95 degrees). Drove home in the PM (75 degrees) she ran like a champ. Does it sound like NAILDRIVER111 may be right with vapor lock???

I would have guessed vaporlock

 

[leener6357]

OK guys I'm back with an update. Replaced fuel filter, fuel pump, ignition module, coil and steel fuel line with rubber. When adding the rubber fuel line I also added a clear (see thru) fuel filter. We are running great at outside temps around 90 but when it gets to about 95 outside she will bog down within a few minutes. Temp guage shows we're still at about 190 engine temp. When I open the hood and let her cool a minute or two she will start right back up and run another few minutes. When looking at the see thru filter it appears to be almost empty at the time that it bogs down. Any suggestions? Thanks

 

[77BroncoWag]

vapor lock

 

[Flash69]

I had a car once that was doing exactly the same thing. It was the distributor cap and rotor. I changed them and it never did it again. I couldnt figure it out and a guy at a goodyear service center told me that was the problem, I didnt beleive him. What can i say he was right. It wont hurt to try that is one of the cheapest things you can try.

 

[leener6357]

Recently replaced the distributor cap and rotor prior to this problem occuring. There are several threads about fuel pumps that seem to have similar symptoms. Maybe I should try an electric fuel pump but it sounds like another guy is having problems with one of those getting hot. Any suggestions as to which one? Brand and model? I am not at all experienced with wiring, but am willing to try anything as this is VERY frustrating. It runs so darn good in the AM and PM but won't run more than 10 minutes in the heat of the day. Thanks!

 

[tompdog7]

i have the same problem. runs about ten minutes and dies. i have replaced all fuel lines, carb twice, fuel filter, fuel pump three times(all got hot and would vapor lock gas), moved pump from engine mount to above frame rail about 2 feet in front of tank. i think after 2 months and lots of money i know what the culprit is. the tank was vented but the vent was leaking so i closed it off. i didnt think that i might not have a vented gas cap. i am going home at lunch today and running it with the cap off and see what happens. good luck.

 

[leener6357]

Here's an update on this problem. I read everything I saw on the forum and tried everything except the electric fuel pump. As I said I'm a novice and worse than that as far as wiring goes. So, I gave up and put it in the shop. After a couple of days they said all the things I had done were right and they couldn't find the problem either. They said they thought they should replace the fuel pump. I said go with electric. They did but put it up front. They test drove enough to think it was fixed. We drove it home and for a day or two then same thing again. Only this time if you left the key turned you could hear the pump continuing to run and if you looked at the glass fuel filter you could see a tiny amount of fuel being pumped. If you waited for the filter to fill she would restart an run a short time (until the filter emptied). I took it back to the shop and had them move the pump to the back (didn't think to insist the first time) and now she has been running great every day for over a week (and its still 90 plus here). Thanks for all the help. From the looks of the forum I was not the only one with this problem.

 

[pooneee]

I had the same problem and all it turned out to be was the heat activated choke on the carb. Because I installed headers and removed the heat stove, the choke stayed open and choked out the engine once it got hot. Close the choke, and it will probably solve your problem. It will still start and run rough until the engine heats up. But, while it is running rough, it sounds like you have a killer cam in it!

Poone.