Car wont restart after sitting for 5min ???

-
Rob38e

Rob38e

Well-Known Member
Joined
Feb 15, 2019
Messages
70
Reaction score
9
Location
Chula Vista , CA
Problem: car initially starts and runs fine, however when it sits ((errands)) even for 5 min it wont turn back on crank , crank ,crank?? Could this be related to the carburetor? Heat? Rich/lean? Or?
Has anyone experienced this or have some insight.
 
Dana67Dart said:
What do you do to get it to start at this point
Click to expand...
Under normal conditions or initial start nothing. Starts right up. If it sits even for about 3 min and I try to start it just turns over but wont start. Ive tried carb cleaner and sometimes that will get it to start.
 
Let me clarify, when it starts at first start I usually drive to were ever im going. Turn off car, run a quick errand and car wont come back on. Hope this gives some insight.
 
Make sure your choke is working properly and not staying closed after the motor is warm. It's unlikely to be a mixture issue. It's also unlikely the issue is fuel evaporation if the problem occurs in just a few minutes.
The first thing I would check is the condition of the fuel pump. If the fuel pump diaphragm has a pinhole in it, it will allow the fuel in the carb to drain back through the pump, leading to vapor lock. It's a fairly common problem.
If you have a transparent fuel filter between the pump and the carb, it will be low or empty after sitting a bit if the pump is bad. If you don't have a filter to "see" the fuel, you can pull the line off the carb and put the line in a bottle or something to catch any fuel. Then have someone crank the motor to see if the pump is working. Be careful here if you're doing this on a hot engine, you don't want fuel to squirt onto a hot manifold and start a fire.
If you determine you have plenty of fuel and the choke's not the problem, then put that all back together and check for spark. You might have a bad ballast resistor, or maybe a coil. I've seen plenty of coils quit working when hot, and work fine 30 minutes later.
 
Rob38e said:
Problem: car initially starts and runs fine, however when it sits ((errands)) even for 5 min it wont turn back on: crank , crank ,crank?? Could this be related to the carburetor? Heat? Rich/lean? Or?
Has anyone experienced this or have some insight.
Click to expand...

I had a warm start problem with electronic ignition.... Check the distributor reluctor gap to the pick-up and make sure it's .007" - .008" with a non-metallic feeler gauge... I have found them too wide, even on new ones, so don't assume the gap is correct even on a new one...
 
How do you get it started? Pedal to the floor?

If so, I'm going to go with ignition lacking initial timing and make fuel percolation issues. Although in 3 minutes the fuel shouldn't get that hot.
 
Rob38e said:
Problem: car initially starts and runs fine, however when it sits ((errands)) even for 5 min it wont turn back on crank , crank ,crank?? Could this be related to the carburetor? Heat? Rich/lean? Or?
Has anyone experienced this or have some insight.
Click to expand...
Same thing happened to me.
Car started fine when the engine was cold, get it hot would not restart no matter what I did.
Replaced ignition box, all is good.
 
Sounds like fuel percolation. Mine did the same until I installed a spacer between the carb that absorbed the heat instead the carb. I have a air gap intake now without the spacer... intake will not get that hot.

To confirm drive the car... get it hot. Shut off engine and remove the air filter. Look down into the carb. If you see fuel coming out of the carb venturis then it is percolation.
 
I second adding a spacer between intake and carburetor to keep the carb from getting hot.

What carburetor are you running?
 
Rob38e said:
Let me clarify, when it starts at first start I usually drive to were ever im going. Turn off car, run a quick errand and car wont come back on. Hope this gives some insight
Click to expand...
Run through this sanario with me...
  • Your car is cold sat over night.
  • You get in and give it a couple pumps of the gas pedal
  • Turn the key and engine cranks over and starts
  • You back out and drive 5 to 10 minutes to the store.
  • Shut off the engine go into store
  • 10 minutes later you come out
  • 1 to 2 pumps of the gas
  • Turn the key, it cranks but it does not start.
  • Try again, cranks but no go
  • 1 to 2 more pumps of gas
  • Turn key, it cranks but it does not start
  • WHAT DO YOU DO NOW?
  • Do you call a tow truck?
Carberator cleaner is not the same as Starter fluid. Cab cleaner will not assist in starting the car.
 
Rob38e said:
Problem: car initially starts and runs fine, however when it sits ((errands)) even for 5 min it wont turn back on crank , crank ,crank?? Could this be related to the carburetor? Heat? Rich/lean? Or?
Has anyone experienced this or have some insight.
Click to expand...
Push gas pedal to the floor before starting it. Hold it there till it starts. Could be high float setting allowing fuel to continue to push through the main booster.
 
My car did that and I could never fix it. Changed a bunch of parts but, nothing fixed it. Except this: an older guy tells me to push slightly on the accelerator, no pumping, not to the floor. Worked every time.
 
So a few updates:
*I do have a spacer between manifold and carburetor
*Aluminum edelbrock carb
*Just replaced my ignition box (today)
* leaned out the carb (today)
And everything seems to be working fine now. Not sure what it was, but thank you all. Hopefully it stays this way and I wont have this annoying issue again.
 
So with an aluminum carb and common E10 gas blends, 10-20 minutes is about the heat soak window for the gas to be boiling in the float bowls. This will make for harder starting. I ran a 1406 on a Wagoneer for years which was an underhood heat monster. I learned a few things that reduced complaints from SWMBO that "her" Jeep was hard to start.

Crank at half throttle when warm. Closed throttle won't move enough air to cool the carb down enough to stop the boil, wide open will lean out.

If you have a mechanical fuel pump, it's normal to have to crank a little to get cool gas to the carb. Aluminum fuel pumps heat-soak worse than zinc, same as carbs. An electric pump goes a LONG way towards cutting the crank time.

An AMC style fuel filter with the return line pointing up might not look pretty, but they are also a big help.

And finally, if you can pop the hood open even a few inches when you park it will help a lot.

Modern fuel injected cars have made us forget some of the "joys" of carburetors.
 
I have no trouble with 87E10, not @1 minute,7 minutes, 20 minutes , whatever minutes. But I do after 6 days,lol.
Assuming your SBM is in good mechanical condition;
check your Transfer-slot exposure. Depending on your cam and compression, it should be square to slightly taller than wide,but NOT LESS than square........ you cannot expect the engine to start if it ain't pulling fuel from the transfers, or if it's pulling too much.
My 367 starts like a Mazda,lol, namely; click-vroom-vroom. And it doesn't care one bit about the ambient temp, once the engine is warm.
Remember;square to slightly taller than wide,but NOT LESS than square
 
You must log in or register to reply here.
-

Back
Top