04-29-2003, 06:34 PM | #1 |
WHYBYNU when old will do
Join Date: Feb 2002
Location: Hot Springs, AR.
Posts: 646
|
Help please...
My truck has a miss in it at around 2500-3000 RPM. I've checked the timing it seems fine plugs&wires are in good shape. The trucks runs fine if you put your foot in it but will miss if you slowly climb up to speed. I pulled the vac advan. line off and the motor speed goes up so
__________________
71 Cheyenne super 2 tone green and white ZZ6 - Th350 4/6 drop 20x8.5 / 20x10 Billet Specialties |
04-29-2003, 06:37 PM | #2 |
WHYBYNU when old will do
Join Date: Feb 2002
Location: Hot Springs, AR.
Posts: 646
|
Sorry I screwed the last part up,not sure what to check next . Any ideals guys? (350 w/stock HEI)
THANKS IN ADVANCE John
__________________
71 Cheyenne super 2 tone green and white ZZ6 - Th350 4/6 drop 20x8.5 / 20x10 Billet Specialties |
04-29-2003, 06:52 PM | #3 |
Registered User
Join Date: May 2000
Location: Victoria, BC, Canada
Posts: 2,409
|
Have a look for any damage in the dist. cap. Any backfiring out the intake when under load? Also, timing chain could have jumped a link or be stretched.
__________________
1970 GMC 1500 Custom Original 350/TH350 Victoria, BC, Canada You can wish in one hand and crap in the other. See which one gets filled first. |
04-29-2003, 06:55 PM | #4 |
Senior Member
Join Date: Dec 2001
Location: Redding,CA...USA
Posts: 4,736
|
Does the rpm go up with the vacuum advance disconected and the line plugged? Which port do you have the vacuum advance hooked to? A couple of things to look at...pull the cap and suck on the vacuum line..it should move the plate..if it dosent look and see if the plate is stuck. If its not stuck, the cannister might be bad/have a hole in it/stuck. The rpm range that you have the miss indicates it is probably in the vacuum advance
Just thought of something else..if the vacuum advance is working correctly, it could be the wire on the pickup thats slightly broken, and when the advance moves the plate it partially breaks the connection. Jim
__________________
It's called "drag racing" if they called it "tic..tic..WHAM!..BANG! F*&K!!!", they'd have to keep the magazines under the counter with the other men's publications click the clicky to join the site.... http://67-72chevytrucks.com/vboard/payments.php 67 lwb..first hotrod in 25 years..540 best ET is 9.45 @ 141.44 Anderson,CA Last edited by bigjimzlll; 04-29-2003 at 06:57 PM. |
04-29-2003, 09:30 PM | #5 |
Nothing fits but the oil
Join Date: Mar 2003
Location: Gaston, Indiana
Posts: 424
|
Do you have the 84 and up HEI with computer controls needed?
__________________
Land of the free Because of the brave |
04-30-2003, 07:47 AM | #6 |
Registered User
Join Date: Dec 1999
Location: New York
Posts: 288
|
my nickel's on a bad plug wire. I had the same thing, and it turned out to be one slightly baked plug wire that was impeding spark at higher rpms.
__________________
RLTW 70C10 72K10 72K10 Cheyenne 72C10 Cheyenne Super |
Bookmarks |
|
|