Starting Problem

[Jerk]

I have a 1993 Fleetwood Flair with a 454 Chevy engine. First think, after sitting awhile (days), hit the key, fires right up. Plugs, Wiring, Distributor and Throttle have all been replaced. Drive it for ten minutes to the gas station, will not restart without cranking for minutes. It is not consistent, however, it happens more often than not. Any advise is welcome.

[MrMark52]

TBI fuel system? Do you smell gas at any point while cranking? What color is the exhaust once it starts?

Check for a leaky injector. Or if (by chance) it’s carbureted, check for sticking float in carb.

[153stars]

Hard to keep track of truck engine slower changes an MH motors a year behind.....If big HEI distributer could be ignition module. Smaller dist cap. with rectangle cut out on side ....its coil was prone to have post just corrode away under coil wire.

[donr103]

You need to preform a simple test.. the next time it happens... spray starting fluids in while cranking.. if it fires and runs.. it's a fuel problem if not it's electrical.. that will get you 50% there.. report back on your results
Good luck and keep us posted

[1972VWbus]

Start with easy stuff first...


1. Remove and clean both ends of the battery cables + & -. Both starter side and battery. Clean, clean, clean. Take a pic prior to removing ends so you can ensure you wire it back up correctly.

[David 70]

When it won't start try holding the gas pedal all the way to the floor. It sounds like a flooding problem. On my 2000 which has port injection (I forget the name at the moment) it would do that, and it was the fuel regulator leaking raw fuel into the intake. You most likely have throttle body, but it will do the same, by holding the throttle wide open you have shut off any fuel delivery. It works the same as the old carbureted engines that would open the choke butterfly when the throtle was held wide open. IF you decide to try the starting fluid thing be extremely careful as if it backfires you can guess your coach goodbye and hopefully it will be the only thing to go up in flames.

[1972VWbus]

Originally Posted by David 70

When it won't start try holding the gas pedal all the way to the floor. It sounds like a flooding problem. On my 2000 which has port injection (I forget the name at the moment) it would do that, and it was the fuel regulator leaking raw fuel into the intake. You most likely have throttle body, but it will do the same, by holding the throttle wide open you have shut off any fuel delivery. It works the same as the old carbureted engines that would open the choke butterfly when the throtle was held wide open. IF you decide to try the starting fluid thing be extremely careful as if it backfires you can guess your coach goodbye and hopefully it will be the only thing to go up in flames.

A TBI system will use the 'Coolant tenp sensor' to initiate extra fuel when the engine is cold (choke condition). If the sensor fails the ECM will either think the engine is cold or hot. That will depend on how the sensor failed (hot condition or cold).

When it fails in the cold condition the engine will receive an overly rich mixture of fuel. If it fails in hot mode the engine will be nearly impossible to start given the ECM will believe the engine is hot vs cold.

[code2e]

Your 1993 has Throttle Body Fuel Injection. Even if it's on a 1992 chassis. The last year for a GM truck carburetor was 1989.

It is possible to have a leaky injector, as mentioned earlier. It could dribble fuel while stopped briefly, resulting in an over rich mixture, hard start.

454's also run hot exhaust. I would check fuel lines down below that may be close enough to exhaust heat to boil the fuel in the line creating a vapor lock. They make insulation for fuel lines to keep fuel cooler. Many styles available on Amazon.

The reply suggesting holding throttle to the floor while starting is a good idea. It is called clear flood mode, designed in the PCM programming. Ignition still fires, no fuel added and lot's of intake air. Will help it start if injectors are the problem.

[donr103]

So if you poured gas into TBI and no start.. then most likely electrical.. so that means.. next check for spark.. just pull any plug wire.. just one.. easiest one to get to.. and take wire and put any old plug you have laying around and hold that against engine.. ground test spark plug and try to start.. see if has spark. Or use timing light.. . while there just look at how old plug wires are.. and condition of wires.. just look at them.. look at side of distributor and wiggle the wires that go there.. get it a try.. with the one test plug and see if that helps.. report back.. could be loose connections or bad coil.. or hall effect sensor inside distributor..
So if you don't have basic automotive repair book for Chevy ck2500 or ck3500 for 1993.. get one.. in engine electrical.. it will show you pictures and walk you through repairs.. you have same engine and transmission for Chevy ck2500 or ck3500.. go online and get one.. I like Haynes and Chilton..
If you could post pictures of coil/distributor.. that would help.. all these parts.. coil, hall effect sensor are so easily changed and very cheap that you can fix with basic hand tools and cheaper than 1hr labor a shop would charge
Good luck and keep us posted

[MrMark52]

For TBI fuel delivery - I would be checking/monitoring fuel line pressure before I did anything else.
The issue could be heat related electrical and I wouldn’t rule that out - but I would also think the ECM would throw codes (may throw codes if a fuel related issue as well). May even be codes there now!

Pouring more gas into an already flooded engine (if a leaky injector) isn’t going to get him anywhere unless he then pulls a plug or two to see if wet or not.

[1972VWbus]

One other thing to add...

The ICM must be functional in order for the injectors to fire fuel. If it is not working ...no fuel.

[Jerk]

I really appreciate all the possibilities. This is what I Have done already" New Throttle Body, New coil, New Plugs and Wiring, new distributor and new Coil. Once the weather warms, I'll remove the cover and change the Coolant Temp Sensor. Thank you everyone. This has me baffled beyond belief.

[MrMark52]

Originally Posted by Jerk

I really appreciate all the possibilities. This is what I Have done already" New Throttle Body, New coil, New Plugs and Wiring, new distributor and new Coil. Once the weather warms, I'll remove the cover and change the Coolant Temp Sensor. Thank you everyone. This has me baffled beyond belief.

What you’ve done so far are no doubt good possibilities - but to me, your throwing parts at it -

Have you scanned the ECM for codes?

What do you have to do to get the engine restarted? Wait? If so, how long?

Have you confirmed fuel rail pressure, both running and allowed pressure drop after shut down?

Coolant temp sensor might do it - but if not, what’s next - without knowing answers to the above?

[donr103]

Check for spark.. when you get the chance.. if you poured gas into engine and no start.. it's missing spark.. or blown engine.. you must have missed or broken a wire when you changed distributor or coil.. I just a thought.. check ignition switch.. they can burn out.. it's only one 10mm bolt and takes 15min.. could be burnt inside..
Good luck and keep us posted