High RPM stumble?

[Jeffyboy]

Hey guys,



I got my truck out after about a month the other day and took it to a cruise night. On the way home, I got into it and at about 4700 rpms, it stumbled all over itself. Then I took it out again the next day and it did the same thing. It doesn\'t seem to do it if I drop a gear and run it up - only if I hammer it from a stop and go through the gears. I\'m not sure, but I don\'t remember it doing it in first gear - just 2nd and 3rd. It had never done it before, so it makes me wonder what\'s up. As far as I know, it gets plenty of fuel. I\'m using an almost-new Holley 110gph mechanical fuel pump and a 750cfm Edelbrock carb (also practically new). Also, I don\'t remember it doing it early in the drive - only after I had been running it for about 15 minutes. Water temp was right at 185-190 and I have an insulating carb gasket and a cowl hood. Any help would be appreciated.



Thanks,



Jeff

[Truckman91]

What ignition are you running? How are your plug wires?

[Jeffyboy]

Hei distributor, Summit 50,000 volt coil (in cap), MSD 6al box, and Accel 8mm wires. I turned off all the lights to see if I could see any arcing, but there wasn\'t any. The plug wires are pretty new, but I should probably check them. I should probably change the cap and rotor, too. Are you leaning toward ignition rather than fuel? While we\'re talking about it, about what gap should I be running on my plugs?



Thanks,



Jeff

[Truckman91]

I was thinking it was an HEI problem, i was thinking you might have a stock HEI...bit you dont.



I seem to remember MSD saying to run around a .050 gap on your plugs.



I typed out the \"light show\" idea, then erased it before I posted, lol.... but you have to remember that its only happening at high RPM and under a load. So even if that was the problem it wouldnt show itself.



I would lean towards an ignition problem, but I very well could be 100% wrong....



Edit: I did your truck with two tone blue/grey and it looks pretty good. I used the body lind that goes down the entire truck as a split point, so its just blue on the top part....

[Jeffyboy]

Sweet. Do you have a link to it? Or you could email it to me - Jeffyboy78@hotmail.com. I look forward to seeing it.



Maybe I\'ll do an ignition tuneup and see what happens. No real time right now, though - might take me a while to get it done. I can still drive it to shows and cruises for the next couple of weeks. That\'ll give me more chance to find out when exactly it\'s doing it, too. Would having too narrow a plug gap possibly do it?



Thanks,



Jeff

[Truckman91]

s10v8.com/members/truckman91/jeff.jpg (http://s10v8.com/members/truckman91/jeff.jpg)

[Jeffyboy]

Looks good!

[tracker]

no why does that look familiar to me???

i have nevr seen your truck b4 and that it the paint scheme i am doing on my 82. now i gotta change it. thought i was the only one with those colors and pattern.



back to the paint shop.....

[Truckman91]

That isnt a real trucks real paint....keep your paint plans.



This is how the truck is really painted...

s10v8.com/members/truckman91/jeffyboys.jpg (http://s10v8.com/members/truckman91/jeffyboys.jpg)



I just used photoshop to add the blue paint. I must have done a good job if you thought it was real??? http://www.s10v8.com/images/smilies/icon_razz.gif

[tracker]

it looked real enuf to me!!!

[Fergusonic]

stumbling problem......changed your fuel filter lately?

[Jeffyboy]

Actually, yeah. I changed it to one of those chrome and glass fancy looking ones and the stupid thing won\'t stay tight. I\'ll be getting rid of that soon, though, so maybe that will help.

[jayg1945]

Had a similar problem and discovered it was inadequate fuel flow. Added a bigger electric fuel pump (120 gal/hr) and a regulator (set at 6 psi) and solved the prob. Good luck.