high rpm hesitation...need help

82 GT · 04-17-2005, 07:09 PM

My problem is my engine struggles just before 5000 rpms except in 1st gear, which is fine(for some reason)
It's almost as if I'm running out of fuel. It runs perfectly fine up until that point though.
It only started doing it after I increased my advance in the dizzy. I have no detonation and the car pulls much harder since then, until it hit about 5K in 2nd and 3rd.
I also recently installed a smaller crank pulley to underdrive the accessories and because I was tossing belts left and right.

My theory is that maybe I have maxed out the limits of my intake and carb and that it's choking off the engine at high rpms.
I was also thinking maybe I should back my timing down a few degrees. Can I have too much advance even though I'm not experiencing detonation? My total timing is at 38* and it's all in by 2500rpms.

rwhite65 · 04-19-2005, 12:28 AM

I did not notice it in your signature, but is that a stock ignition set up?
Ryan

Jeff Chambers · 04-19-2005, 07:06 AM

38 seems a bit much to me. I've never seen an engine like yours really care for any more than about 34-degrees of timing. That carb is also starting to get to be pretty small for a engine of that size spinning at 5K+. Put a good Holley 750 4150 on it.

82 GT · 04-19-2005, 02:50 PM

I have plans on getting a stealth intake and 750 pretty soon.
Do you think if I have too much timing that it could cause my problem or do you think it's more of a fuel issue now.
rwhite65 I have a Mallory electronic dizzy and a blaster 2 coil.

rwhite65 · 04-19-2005, 11:26 PM

Well, I think Jeff Chambers is on to something here the more I think about it, I think your carb is not enough to push that engine. If it is not detonating, I am not so sure it is to much timing.
Ryan

82 GT · 04-21-2005, 09:47 PM

I put my friend's 750 holley on it tonight and that made all the difference in the world!! It pulls hard through 6K.
All I need now is the stealth intake.

04-17-2005, 07:09 PM	#1
82 GT Import Slayer Join Date: May 1999 Posts: 2,241	high rpm hesitation...need help My problem is my engine struggles just before 5000 rpms except in 1st gear, which is fine(for some reason) It's almost as if I'm running out of fuel. It runs perfectly fine up until that point though. It only started doing it after I increased my advance in the dizzy. I have no detonation and the car pulls much harder since then, until it hit about 5K in 2nd and 3rd. I also recently installed a smaller crank pulley to underdrive the accessories and because I was tossing belts left and right. My theory is that maybe I have maxed out the limits of my intake and carb and that it's choking off the engine at high rpms. I was also thinking maybe I should back my timing down a few degrees. Can I have too much advance even though I'm not experiencing detonation? My total timing is at 38* and it's all in by 2500rpms. __________________ '82 GT 351W (.060)Comp Cams 274* Extreme Energy cam, ported & polished heads w/ 1.94/1.60 valves 10.3:1 flat top pistons,stealth intake, Mallory dizzy,Holley 750dp carb, BBK shorties,Flowmaster exhaust,C-4 with 3700 stall converter, B&M pro shifter,8.8 rear, 4:10's, subframes, electric fan, powermaster alternator, 4 core radiator.

04-19-2005, 12:28 AM	#2
rwhite65 Ride Hard Join Date: Oct 2000 Location: Wyoming IL Posts: 1,094	Re: high rpm hesitation...need help I did not notice it in your signature, but is that a stock ignition set up? Ryan __________________ 65 Fastback 91 roller 306, H/C/I AOD-Bauman, PI Stallion, 4.10's and traction loc 04 Grand Cherokee Freedom Edition 79 Ford F-250 4x4 - Restored

04-19-2005, 07:06 AM	#3
Jeff Chambers Moderator Join Date: Aug 2000 Location: Milan, OH Posts: 2,699	Re: high rpm hesitation...need help 38 seems a bit much to me. I've never seen an engine like yours really care for any more than about 34-degrees of timing. That carb is also starting to get to be pretty small for a engine of that size spinning at 5K+. Put a good Holley 750 4150 on it. __________________ Jeff Chambers 1990 Mustang GT 10.032 Seconds / 137.5 MPH 14-time Street Warrior World Record Setter CRT Performance 2001 Tropic Green Mustang GT - 12.181 / 113.2 MPH 2002 Ford F-250 Crew Cab 7.3l Power Stroke - 17.41@77.2 "There's nothing boring about a small block automatic shifting gears at 9400 rpm!"

04-19-2005, 02:50 PM	#4
82 GT Import Slayer Join Date: May 1999 Posts: 2,241	Re: high rpm hesitation...need help I have plans on getting a stealth intake and 750 pretty soon. Do you think if I have too much timing that it could cause my problem or do you think it's more of a fuel issue now. rwhite65 I have a Mallory electronic dizzy and a blaster 2 coil. __________________ '82 GT 351W (.060)Comp Cams 274* Extreme Energy cam, ported & polished heads w/ 1.94/1.60 valves 10.3:1 flat top pistons,stealth intake, Mallory dizzy,Holley 750dp carb, BBK shorties,Flowmaster exhaust,C-4 with 3700 stall converter, B&M pro shifter,8.8 rear, 4:10's, subframes, electric fan, powermaster alternator, 4 core radiator.

04-19-2005, 11:26 PM	#5
rwhite65 Ride Hard Join Date: Oct 2000 Location: Wyoming IL Posts: 1,094	Re: high rpm hesitation...need help Well, I think Jeff Chambers is on to something here the more I think about it, I think your carb is not enough to push that engine. If it is not detonating, I am not so sure it is to much timing. Ryan __________________ 65 Fastback 91 roller 306, H/C/I AOD-Bauman, PI Stallion, 4.10's and traction loc 04 Grand Cherokee Freedom Edition 79 Ford F-250 4x4 - Restored

04-21-2005, 09:47 PM	#6
82 GT Import Slayer Join Date: May 1999 Posts: 2,241	Re: high rpm hesitation...need help I put my friend's 750 holley on it tonight and that made all the difference in the world!! It pulls hard through 6K. All I need now is the stealth intake. __________________ '82 GT 351W (.060)Comp Cams 274* Extreme Energy cam, ported & polished heads w/ 1.94/1.60 valves 10.3:1 flat top pistons,stealth intake, Mallory dizzy,Holley 750dp carb, BBK shorties,Flowmaster exhaust,C-4 with 3700 stall converter, B&M pro shifter,8.8 rear, 4:10's, subframes, electric fan, powermaster alternator, 4 core radiator.

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