Author Topic: Hard start when WARM  (Read 5912 times)

Offline squarebodyeric

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Hard start when WARM
« on: August 18, 2017, 11:52:06 AM »
hello,
I have read multiple forums and asked multiple people not sure what to try next.
some specs and steps I've tried below. (i am nowhere close to being a mechanic just like to turn wrench's a bit)
1983 squad body 350 5.7 1604 carb 1inch spacer.

Confirmed steps
fuel pressure 5.4 confirmed at carb by fuel pressure gauge.
choke open.
Hi-torque mini starter with heat shield.
headers wrapped with DEI TITANIUM.
I usually operate at 190 never go over even with AC on.
Brand new HEI street fire distributor.

starts like a champ cold , after i reach 190 park it come back less than 30 mins starts like a champ ....let it rest longer than 30mins hard start.Have to hold ignition and pump and few times.






Couple Pics






https://ibb.co/fCJFbk
https://ibb.co/hSdRhQ
https://ibb.co/iNCmhQ
https://ibb.co/cjTv95
https://ibb.co/fWPfbk
https://ibb.co/fD9A95
« Last Edit: August 20, 2017, 04:14:08 PM by Irish_Alley »

Offline Stewart G Griffin

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Re: Hard start when WARM
« Reply #1 on: August 19, 2017, 08:54:49 AM »
What is your starting procedure, both hot and cold?


2) Also, this may or may not be related, but the red plastic fuel line has got to go ASAP!  This is a fire hazard waiting to happen!

Offline AZ4X4SQBDY

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Re: Hard start when WARM
« Reply #2 on: August 19, 2017, 09:20:55 AM »
My first thought is it's boiling the fuel out of the float bowls from heat soak. A number of factory lower carb gaskets are 1/4" thick and act as an insulator to prevent this. Your 1" spacer is aluminum and still conducting heat.

My second thought is there is something internally leaking, I am not that familiar with that carb but it's well known to epoxy the well plugs on Quadrajets because of this issue.

Shut it off, pull the air cleaner and look down the bores of the carb, it may take a minute or two but you would hear a sizzling sound and may see the fuel being pulled past the boosters. Or you could hit it with a IR temperature gun and see if the temp is rising after shutting it off.
« Last Edit: August 19, 2017, 09:26:13 AM by AZ4X4SQBDY »
1987 GMC Sierra Classic 4x4 short, fleet, 1985 Chevrolet Silverado 4x4 short, step side, '87 Chevy Silverado short fleet, '91 Dodge Ramcharger LE 4x4,
2005 Porsche Boxster S,1982 Alfa Romeo Spider Veloce

Offline squarebodyeric

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Re: Hard start when WARM
« Reply #3 on: August 20, 2017, 11:27:10 AM »
I don't have a procedure for starting cold, when cold I bump the key literally once with my foot nowhere near the gas pedal and it fires right up.
When warm (185-212) I try to turn over starter turns the motor just fine(does not sound slow brand new high torque starter), usually I have to continue holding the key and pumping and i here a huge fire and it turns on.
also, i feel like I am running lean and hotter than I should. could all this be timing?

I'm running 4 core huge radiator with a flex fan(mechanical) and one electric fan in front of my condenser A/C.

this is also a new crate motor 350 from summit, 3months with the proper break in procedure done.

I set the timing by feel and by the way the truck ran, don't ask me why but my balancer is the incorrect year because the notch is nowhere near where it should be best I can do is adjust slightly advance or back.
remember she starts so great cold and when she's driving and I slam the pedal no back fire, misses she takes off great.
« Last Edit: August 20, 2017, 11:35:53 AM by squarebodyeric »

Offline squarebodyeric

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Re: Hard start when WARM
« Reply #4 on: August 20, 2017, 11:36:41 AM »
btw ill get rid of the red line.

Offline blazer74

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Re: Hard start when WARM
« Reply #5 on: August 21, 2017, 12:05:44 AM »
What's your fuel pressure prior to your hard start issues. If pressure rises due to heat soak could cause fuel to drop into manifold.

Offline squarebodyeric

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Re: Hard start when WARM
« Reply #6 on: August 21, 2017, 10:23:36 AM »
gauge reads 5.5 i believe i will confirm

Offline blazer74

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Re: Hard start when WARM
« Reply #7 on: August 21, 2017, 09:57:25 PM »
Underhood temps can cause fuel in the lines to expand and fuel psi to rise too high and causing issues

Offline septantrionalis

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Re: Hard start when WARM
« Reply #8 on: August 23, 2017, 11:54:03 AM »
I just want to say that my truck has this exact problem.  I've never solved it but would love to.  On a cold start, the truck fires right up.  Park and go in under 30 minutes and it fires up.  Anything over 30 minutes on a warm day and its a $#@% to start up.

Offline blazer74

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Re: Hard start when WARM
« Reply #9 on: August 23, 2017, 02:24:00 PM »
I just want to say that my truck has this exact problem.  I've never solved it but would love to.  On a cold start, the truck fires right up.  Park and go in under 30 minutes and it fires up.  Anything over 30 minutes on a warm day and its a $#@% to start up.

Hold the pedal to the floor next time, if it starts and clears up easier you  could have minor flooding from fuel drip.  Ethanol fuel doesn't help either.

Offline squarebodyeric

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Re: Hard start when WARM
« Reply #10 on: August 25, 2017, 03:14:03 PM »
I'll give that a try as soon as Hurricane Harvey passes !!! >:(

Offline blazer74

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Re: Hard start when WARM
« Reply #11 on: August 25, 2017, 07:05:31 PM »
 Good luck with the storm

Offline squarebodyeric

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Re: Hard start when WARM
« Reply #12 on: September 05, 2017, 11:19:20 PM »
ok,
now that Harvey passed I had time to work some things.. got the issue fixed.
I bought a phenolic spacer and swapped out my aluminum got a 1inch"
I also switched back to standard 3/8" fuel line and got rid of the red lines.

Also, go figure I had no idea the water pump I bought with this crate motor spins counter clockwise so...
I was building a lot of heat and not getting adequate circulation under my hood forcing hot air back toward my radiator.

So fixed two things here.

Offline VileZambonie

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Re: Hard start when WARM
« Reply #13 on: September 06, 2017, 06:14:32 AM »
You haven't truly defined the issue you are having. Hard start means many things so clarify what you are saying:

Slow crank, starter turns engine slowly with resistance?

Cranks fine, engine does not start easily when warm?

Be more descriptive on what is actually happening. As far as setting the timing, what you did is fine to get you up and running but you have no baseline settings to work from. I would suggest creating your own mark on the balancer at true TDC and recording your timing settings. From there you can track your adjustments and properly dial it in.
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Offline AZ4X4SQBDY

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Re: Hard start when WARM
« Reply #14 on: September 06, 2017, 07:26:46 PM »
I believe the OEM serpentine belt set up, which I think is what your using, rotates counter clockwise. So yes, the fan was spinning the wrong way. It's important to use the correct water pump with the brackets you are using.
1987 GMC Sierra Classic 4x4 short, fleet, 1985 Chevrolet Silverado 4x4 short, step side, '87 Chevy Silverado short fleet, '91 Dodge Ramcharger LE 4x4,
2005 Porsche Boxster S,1982 Alfa Romeo Spider Veloce