Car dies after 20 mins. - Chevelle Tech

Performance Our High Performance area

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
post #1 of 21 (permalink) Old May 30th, 07, 8:50 PM Thread Starter
Tech Team
 
Join Date: Sep 2002
Location: New York
Posts: 125
Car dies after 20 mins.

Well now that my whole distrubitor is changed its HEI, due to my lack of spark when the car got hot, now the car just dies when i put it in gear after it warms up. And im gettin spark now even when it dies.

Never happened before, And to get it to start again, i have to put my foot basically all the way into it and play with the gas for a few second to get it to idle again. then dies immediatley and backfires through the carb when put in gear....what is my problem>? PS the car never runs hotter then 170, its a 355 sbc.

When it gets cold again, im gunna start it and see if it will run in gear while still not fully warm. Ill let everyone know if it runs like that or not.

Thanks guys
jcchevelle is offline  
Sponsored Links
Advertisement
 
post #2 of 21 (permalink) Old May 30th, 07, 9:00 PM
Senior Tech Team
Gary
 
Join Date: Feb 2007
Location: Kansas City,Mo.
Posts: 3,006
Re: Car dies after 20 mins.

If your sure the timimg is right it sounds like its to lean at idle. check for vacuum leaks and anything you disturbed while working on it. I assume it has a choke and thats why it will idle cold.
gnicholson is offline  
post #3 of 21 (permalink) Old May 30th, 07, 9:09 PM Thread Starter
Tech Team
 
Join Date: Sep 2002
Location: New York
Posts: 125
Re: Car dies after 20 mins.

Quote:
Originally Posted by gnicholson View Post
If your sure the timimg is right it sounds like its to lean at idle. check for vacuum leaks and anything you disturbed while working on it. I assume it has a choke and thats why it will idle cold.
Why, and how would it change all of a sudden? And does that explain the backfiring? Thanks Again
jcchevelle is offline  
post #4 of 21 (permalink) Old May 30th, 07, 9:30 PM
Tech Team
Patrick
 
Join Date: Jun 2005
Location: West Palm Beach
Posts: 672
Re: Car dies after 20 mins.

I had that happen to me once. car would start fine but after a while it would die. Occasionally I would notice a very strong fuel scent. Ended up that one of my main jets was clogged with clear wrap after I rebuilt it. Even a small amount of debris in the carb can cause all kinds of problems.

Patrick
bb489 is offline  
post #5 of 21 (permalink) Old May 30th, 07, 9:56 PM Thread Starter
Tech Team
 
Join Date: Sep 2002
Location: New York
Posts: 125
Re: Car dies after 20 mins.

hey guys, just to make sure, about my timing, heres what i got running, maybe someone can give me some input on what they reccomend for timing.

355 sbc
Sportsman II heads
vodoo cam-- Advertised duration 276/284
Duration @ .050 233/241
valve lift .504/.525
LSA/ICL 110/106

Magnum roller tips
10:1 comp.
i also have a high output mechanical fuel pump, with a regulator set to about 5 psi. ( it always varys..i think from the heat)

i have my intial at about 16-18 with my vaccume plugged at idle, Its and a brand new Proform HEI high performance distributor. sound about right for this engine?
jcchevelle is offline  
post #6 of 21 (permalink) Old May 30th, 07, 10:13 PM
Tech Team
 
Join Date: Jan 2001
Location: Fallbrook, CA, USA
Posts: 543
Re: Car dies after 20 mins.

That sounds like a lot of initial. Use whatever works best, don't stick to a certain number. Kinda does sound like a vacuum leak though. Is your vacuum advance hooked up to full or ported? Does it die with the vacuum advance disconnected and plugged?
Fried_Guy is offline  
post #7 of 21 (permalink) Old May 31st, 07, 9:46 AM
Senior Tech Team
Bryan
 
Join Date: Apr 2007
Location: San Antonio, Texas
Posts: 5,040
Re: Car dies after 20 mins.

If the HEI is using existing wiring---that could be the culprit.
Cannot use the existing ballast or resistor wire, need a good 12ga or bigger wire run frrom the ign sw to the dizzy.

Also could be a FUBARed module or coil.

my 59 was doing that (shutting down---no start) and I changed the coil and the module, not a problem since.
Still not sure what the culprit was---have not bothered to check the coil.

Modules can check okay----but when they heat up, can fail.

Bryan

Bryan's toyz

59 ElCamino 454/TKO 5spd--(daddy)
66 ElCamino 3oh7/TKO 5spd (mousey) Almost done On the street now!!!
65 Ranchero v8/4-spd, that my uncle bought new
Bryan59EC is offline  
post #8 of 21 (permalink) Old May 31st, 07, 4:55 PM Thread Starter
Tech Team
 
Join Date: Sep 2002
Location: New York
Posts: 125
Re: Car dies after 20 mins.

Quote:
Originally Posted by Bryan59EC View Post
If the HEI is using existing wiring---that could be the culprit.
Cannot use the existing ballast or resistor wire, need a good 12ga or bigger wire run frrom the ign sw to the dizzy.

Also could be a FUBARed module or coil.

my 59 was doing that (shutting down---no start) and I changed the coil and the module, not a problem since.
Still not sure what the culprit was---have not bothered to check the coil.

Modules can check okay----but when they heat up, can fail.

Bryan

Bryan, the module and coil are both new, and it was hei to begin with, this is not a swap from points, and the coil is 10 or 12 guage, not a small 16 guage wire or anything like that.
jcchevelle is offline  
post #9 of 21 (permalink) Old May 31st, 07, 6:18 PM
Tech Team
Patrick
 
Join Date: Jun 2005
Location: West Palm Beach
Posts: 672
Re: Car dies after 20 mins.

Again, make sure your carb is clean inside without debris. I don't think a vacuum leak would only cause it to die when it is warm and timing is timing. Once it is set right, it is not going to change when your car warms up. My bet is either you got a tooth or two off with the rotor when you put the dizzy back in, or your carb is dirty inside and may be holding a needle and seat open causing it to flood and die. The next time it happens, hop out real quick and see if your carburetor inlet and venturi are all wet with fuel. I had the EXACT same symptoms as you and as I said earlier it turned out to be a piece of debris in one of my main jets.

Patrick
bb489 is offline  
post #10 of 21 (permalink) Old May 31st, 07, 8:15 PM
Tech Team
eric
 
Join Date: Apr 2007
Location: tampa florida
Posts: 390
Re: Car dies after 20 mins.

Quote:
Originally Posted by jcchevelle View Post
Bryan, the module and coil are both new, and it was hei to begin with, this is not a swap from points, and the coil is 10 or 12 guage, not a small 16 guage wire or anything like that.
don't consider a part good beause it is new!!!!I work in a dealership and replace "good new parts" all too often.in todays age of everything made in mexico or china I take no chances. good luck
eric
flpackerbacker is offline  
post #11 of 21 (permalink) Old May 31st, 07, 10:33 PM
Senior Tech Team
Bryan
 
Join Date: Apr 2007
Location: San Antonio, Texas
Posts: 5,040
Re: Car dies after 20 mins.

Quote:
Originally Posted by flpackerbacker View Post
don't consider a part good beause it is new!!!!I work in a dealership and replace "good new parts" all too often.in todays age of everything made in mexico or china I take no chances. good luck
eric
My 59 Elky had less than 400 miles on a BRAND NEW mallory HEI

yep new parts can be bad

9 mo and a bit over 2000 more miles----no issues (whole car only has 2550mi on it)

Bryan

Bryan's toyz

59 ElCamino 454/TKO 5spd--(daddy)
66 ElCamino 3oh7/TKO 5spd (mousey) Almost done On the street now!!!
65 Ranchero v8/4-spd, that my uncle bought new
Bryan59EC is offline  
post #12 of 21 (permalink) Old May 31st, 07, 10:54 PM
Tech Team
Antonio
 
Join Date: Apr 2007
Location: Nutley NJ
Posts: 87
Re: Car dies after 20 mins.

Just make sure when your checking for the "wet spots" its not just about ready to blow your head off... I've had a carb spit fire on a buddy while he was being curious and he lost his eyebrows and bangs... all in one puff!..

Where safety glasses if your going in head first. :-)

1969 Chevelle Malibu
383 Stroker 425HP/700r4
In Progress:
Springs and shocks
...and everything else
Ando is offline  
post #13 of 21 (permalink) Old Jun 1st, 07, 10:04 AM
Senior Tech Team
Bryan
 
Join Date: Apr 2007
Location: San Antonio, Texas
Posts: 5,040
Re: Car dies after 20 mins.

Quote:
Originally Posted by Ando View Post
Just make sure when your checking for the "wet spots" its not just about ready to blow your head off... I've had a carb spit fire on a buddy while he was being curious and he lost his eyebrows and bangs... all in one puff!..

Where safety glasses if your going in head first. :-)
Also no nylon or rayon type clothing!!!!!!!!!!!!!!

My father was burned on about 30% of his body when his shirt caught a
carb burp, and only took an instant for his clothes to melt to his body.
3 weeks in a burn unit---and then had to stay out of the sun for the next 5 yrs.
Had to sell his new boat (27' Scarab), cause he could not take it out anymore to enjoy it.

100% cotton won't melt to you

Bryan's toyz

59 ElCamino 454/TKO 5spd--(daddy)
66 ElCamino 3oh7/TKO 5spd (mousey) Almost done On the street now!!!
65 Ranchero v8/4-spd, that my uncle bought new
Bryan59EC is offline  
post #14 of 21 (permalink) Old Jun 1st, 07, 12:54 PM
Senior Tech Team
Ken
 
Join Date: Sep 2005
Location: Missouri
Posts: 2,556
Re: Car dies after 20 mins.

All of what Bryan59EC says: I would still replace the module. I had to buy 4 thermostats before I got one that worked right. Modules are much more complicated. And cantankerous.

Make sure you dist cap is spotless inside; that there is no oil or dirt that could be carbon tracking. Always wear some kind of clean gloves when working on ignition parts to keep finger prints off high voltage parts.

kirkwoodken
406 SB, Original Bill Thomas '63 Rochester FI
AFR 210, Lunati 501C2LUN, 255/263@.050", .628"
10:1, TH400, 3.31's, 4400 SS

"Life is too short to not run a solid roller cam."
"Nothing is impossible; if you don't know what you're talking about."
Kirkwoodken
kirkwoodken is offline  
post #15 of 21 (permalink) Old Jun 1st, 07, 1:01 PM
Tech Team
 
Join Date: Aug 2003
Location: New Boston, NH
Posts: 105
Re: Car dies after 20 mins.

You say your getting spark when it dies, is getting fuel when it dies? Could be fuel system issues (ie: heat soak, debris, clogged filter)

71 Chevelle SS: 396+.06 10:1, t-56, 4:10, Lunati 00024, merlin ovals<br />72 Chevelle ss: 350+.030 10.5:1, 150 n20, ST-10, 4:56. 1.76 60', 11.81@115
71rat408 is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Chevelle Tech forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address. Note, you will be sent a confirmation request to this address.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools Search this Thread
Show Printable Version Show Printable Version
Email this Page Email this Page
Search this Thread:

Advanced Search
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome