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Author Topic:   GM HEI
racer2
Dirt Freak

Total posts: 352
posted May 03, 2005 01:06 PM  
I have a high rpm miss.running a hei with no alternator.turn around 7300 rpm alcohol modified. ive changed distributars with no luck. even put a ground on motor,unpluged tack,put new on off power switch.ect...
thx in advance

mdsteacher
Dirt Maniac

Total posts: 145
posted May 03, 2005 02:25 PM  
Running high rpms requires a very good hei distributor (MSD, DUI, etc.) and very good plug wires (Ultra-40's). Might just be poor distributors.

racer2
Dirt Freak

Total posts: 352
posted May 03, 2005 02:47 PM  
BTT

autoshop
Dirt Freak

Total posts: 298
posted May 03, 2005 04:29 PM  
if your running 180 degree headers you need to shield away the heat at the distributor, they don't like to have any heat near them or they will miss under a load

racer2
Dirt Freak

Total posts: 352
posted May 03, 2005 05:05 PM  
sure dont but thx anyway..
cmon guys anything im missing??????

eenfield
Dirt Maniac

Total posts: 116
posted May 03, 2005 05:41 PM  
Did this problem just start happening, or is it an ongoing thing? Are you running lean? Water in the fuel maybe???

If you are sure it is electical, have you checked that the plugs, and plug wires are good,(no cracked plugs or burnt wires or boots) the cap, and rotor are good, or you didnt just end up with two junk distrabuters? Then check your running voltage during the problem. Maybe you are just droping to many volts for one reason or another.

racer2
Dirt Freak

Total posts: 352
posted May 03, 2005 06:03 PM  
i tried 3 differant distributers caps and rotors.i dont know for sure if it electrical. i jetted up and down.it runs fine but when theres a pull on it it ****s out around 6000 and pops through the exhaust.
new msd wires,i will check running voltgage
tomorrow
thx

racerman707
Dirt Freak

Total posts: 374
posted May 03, 2005 06:56 PM  
Check your compression and valve adjustment too.

speedy46
Dirt Maniac

Total posts: 165
posted May 03, 2005 08:43 PM  
sounds like u could be floating the valves what kind of valve springs do u have on it??? and how old are they?

[This message has been edited by speedy46 (edited May 03, 2005).]

Jesterondirt
Dirt Full Roller

Total posts: 56
posted May 03, 2005 09:17 PM  
try running it in the dark, look for some jumping sparks

thirty2rocksu
Dirt Roller

Total posts: 18
posted May 03, 2005 09:35 PM  
quote:
Originally posted by Jesterondirt:
try running it in the dark, look for some jumping sparks

tighten your plug gap up to .030

streetstock82
Dirt Forum Racer

Total posts: 81
posted May 03, 2005 09:54 PM  
check your timing at high rpm and make sure its not retarding. If your pick up is bad, or your cam is walking it can give you fits. also check your gaer mesh. That can be trouble too. What kind of cam and distributor gear are you using?

cjodell
Dirt Roller

Total posts: 7
posted May 03, 2005 10:24 PM  
thank you all, will check more stuff on it today,compression is good,valves are adjusted,cam timing is not retarding,gonna check valve springs today
again thx

ss99
Dirt Maniac

Total posts: 120
posted May 04, 2005 07:03 AM  
we had this problem two seasons ago - ended up being a few valve guides that were galled causing the valves to stick just enough to cause the missing.

blum8000
Dirt Newbie

Total posts: 1
posted May 05, 2005 08:20 AM  
Vacume leak. Check the intake manifold


zero5334
Dirt Newbie

Total posts: 2
posted May 10, 2005 04:12 PM  
could be a voltage problem. try hooking a 6 volt battery in series with your 12 volt battery and just run your ignetion off of the 18 volts.

racer2
Dirt Freak

Total posts: 352
posted May 11, 2005 07:04 AM  
quote:
Originally posted by zero5334:
could be a voltage problem. try hooking a 6 volt battery in series with your 12 volt battery and just run your ignetion off of the 18 volts.

i put my 16.5 volt cordles screw gun battery
on it ,still missed,have a new dui distributor comming this morning.will post if it fixes it..I changed carb no luck either.
thank you

[This message has been edited by racer2 (edited May 11, 2005).]

racer2
Dirt Freak

Total posts: 352
posted May 12, 2005 07:05 AM  
put DUI distributor in ,no luck,pulled intake and the bottom of the intake ports were not sealing.will let ya know if this fixes it.

racer2
Dirt Freak

Total posts: 352
posted May 16, 2005 02:50 PM  
thanks for all the help. i had a few bent exhaust valves

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