Hard starting when eng is hot - The 1947 - Present Chevrolet & GMC Truck Message Board Network

76bonanza · 02-12-2004, 06:21 PM

I have a truck That starts fine when cold. But if the engine is hot it just cranks three or four times untill it finally starts.

Any thoughts?

low 84 · 02-12-2004, 06:45 PM

timing advanced to far? solinoid getting heat soaked, might need replacement?

flip66 · 02-12-2004, 07:50 PM

is it a 350 if so dose the starter have heat sheild on it.

76bonanza · 02-12-2004, 08:07 PM

Not sure it is a dodge like 73 or 74 not mine buddies

78chevstepside · 02-12-2004, 08:35 PM

I have the same problem( wont start when hot). I have had the problem for a while. I thought it was the heat from the headers. I put in a quality starter , heat bag, extra heavy positive cable to starter. One day it wouldnt start after getting warm. While cranking the engine I saw the engine ground smoking. I replaced the engine ground(the one from the heads to the cab in the back) Iam considering running a cable from the frame to the engine to make a extra good ground. any thoughts?

NeCrOmAnCeR · 02-12-2004, 09:02 PM

Unless I am misreading the original post, the engine is turning over OK when trying to start, but it fails to catch. Things you might want to look for are heat soak of the carb where the fuel might have boiled out of the float bowl, or vapor lock of the fuel pump. Also check the health of the ignition system.

76bonanza · 02-12-2004, 09:10 PM

yes Necromancer cranks hard just does not turn over.

NeCrOmAnCeR · 02-12-2004, 09:17 PM

Also check to see if fuel is being siphoned back out of the float bowl due to a bad check valve in the fuel pump.

rolson1039 · 02-12-2004, 09:56 PM

Quote:

Originally posted by 78chevstepside
I have the same problem( wont start when hot). I have had the problem for a while. I thought it was the heat from the headers. I put in a quality starter , heat bag, extra heavy positive cable to starter. One day it wouldnt start after getting warm. While cranking the engine I saw the engine ground smoking. I replaced the engine ground(the one from the heads to the cab in the back) Iam considering running a cable from the frame to the engine to make a extra good ground. any thoughts?

you cant "over ground" so yes its a good idea and any grounds ya have will definately help.

*zzChevy* · 02-12-2004, 10:00 PM

Quote:

Originally posted by low 84
timing advanced to far? solinoid getting heat soaked, might need replacement?

I'd question the timng as well. Had it happend on an '86 after a short rebuild. Had to replace the timing belt after 20,000 miles. Boy was I pissed.

Blue Beard · 02-12-2004, 10:30 PM

Mine was doing that till I found the positive cable shorting on the block behind the headers....

78chevstepside · 02-12-2004, 10:38 PM

When my truck gets hot it loses cranking power. the engine ground strap gets hot if cranking while hot. Let cool off for about 20 minutes and it cranks fine.

*1FaastC10* · 02-13-2004, 06:53 PM

Quote:

Originally posted by 78chevstepside
While cranking the engine I saw the engine ground smoking.

replace your battery cables, especially the negative one. and check all of the connections to it, and between the accessories and the block. the smoking ground says that you are not getting proper ground through the route that its supposed to take (the negative cable). i bet if you look, you'll find your body ground (between body and fender) is either also hot or melted. because it cant get proper ground, or enough ground, it takes the path of least resistance, which on your truck just happens to be at the ground strap.

78chevstepside · 02-22-2004, 03:19 AM

I always ran my battery ground fron the battery to the frame. And I have always had problems with starting when hot. All my cables are brand new. I ran another cable from the frame to the alt. bracket. This solved my problem with hot engine starting. This has been a on going problem with my truck for a long time. where does everyone else have the ground cables attached? any comments?

02-12-2004, 06:21 PM	#1
76bonanza Senior Member Join Date: Mar 2003 Location: St robert Mo Posts: 2,001	Hard starting when eng is hot I have a truck That starts fine when cold. But if the engine is hot it just cranks three or four times untill it finally starts. Any thoughts? __________________ 1968 c10 lowered 3" 4" 355/Th400 built by Hatfield racing in joplin MO

02-12-2004, 06:45 PM	#2
low 84 Registered User Join Date: Jan 2002 Location: Houston, TX Posts: 2,144	timing advanced to far? solinoid getting heat soaked, might need replacement? __________________ '51 F100, backhalf with a narrowed 9 and coil overs, 18.5" mickeys, monte front clip, +400" sbc in the works '05 1500 Crew Cab RIP '84 swb 5/7 drop, solid cammed 408 w/ fully ported dart heads, th350 w/ 10 inch hughes, 12 bolt w/ 3.73 richmonds and a locker '80 swb 4x4 in progress: 7" lift, 350 th350/np205, d44 and 1.5" ORD tie rod, 14BFF w/discs , armored diff covers, 40" MTR's

02-12-2004, 08:07 PM	#4
76bonanza Senior Member Join Date: Mar 2003 Location: St robert Mo Posts: 2,001	Not sure it is a dodge like 73 or 74 not mine buddies __________________ 1968 c10 lowered 3" 4" 355/Th400 built by Hatfield racing in joplin MO

02-12-2004, 09:10 PM	#7
76bonanza Senior Member Join Date: Mar 2003 Location: St robert Mo Posts: 2,001	yes Necromancer cranks hard just does not turn over. __________________ 1968 c10 lowered 3" 4" 355/Th400 built by Hatfield racing in joplin MO

02-12-2004, 10:30 PM	#11
Blue Beard Registered User Join Date: Jan 2003 Location: Washington State Posts: 8,834	Mine was doing that till I found the positive cable shorting on the block behind the headers.... __________________ 1970 Chev CST 2003 Harley Fatboy 1975 Chevrolet Step Van 1956 Chev Bel Air 1977 Blazer 2WD For Sale $3000.00 1978 Blazer 2WD For Sale $7000.00 1978 Silverado 2005 Monte Carlo

02-12-2004, 07:50 PM	#3
flip66 Registered User Join Date: Jan 2004 Location: Garland TX Dallas area Posts: 658	is it a 350 if so dose the starter have heat sheild on it.

02-12-2004, 08:35 PM	#5
78chevstepside Registered User Join Date: Nov 2002 Location: lacenter, washington Posts: 718	I have the same problem( wont start when hot). I have had the problem for a while. I thought it was the heat from the headers. I put in a quality starter , heat bag, extra heavy positive cable to starter. One day it wouldnt start after getting warm. While cranking the engine I saw the engine ground smoking. I replaced the engine ground(the one from the heads to the cab in the back) Iam considering running a cable from the frame to the engine to make a extra good ground. any thoughts?

02-12-2004, 09:02 PM	#6
NeCrOmAnCeR Registered User Join Date: Feb 2004 Location: Hodgenville, Ky Posts: 735	Unless I am misreading the original post, the engine is turning over OK when trying to start, but it fails to catch. Things you might want to look for are heat soak of the carb where the fuel might have boiled out of the float bowl, or vapor lock of the fuel pump. Also check the health of the ignition system.

02-12-2004, 09:17 PM	#8
NeCrOmAnCeR Registered User Join Date: Feb 2004 Location: Hodgenville, Ky Posts: 735	Also check to see if fuel is being siphoned back out of the float bowl due to a bad check valve in the fuel pump.

02-12-2004, 10:38 PM	#12
78chevstepside Registered User Join Date: Nov 2002 Location: lacenter, washington Posts: 718	When my truck gets hot it loses cranking power. the engine ground strap gets hot if cranking while hot. Let cool off for about 20 minutes and it cranks fine.

02-22-2004, 03:19 AM	#14
78chevstepside Registered User Join Date: Nov 2002 Location: lacenter, washington Posts: 718	I always ran my battery ground fron the battery to the frame. And I have always had problems with starting when hot. All my cables are brand new. I ran another cable from the frame to the alt. bracket. This solved my problem with hot engine starting. This has been a on going problem with my truck for a long time. where does everyone else have the ground cables attached? any comments?



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.