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Topic: Lots of hesitation when on heavy accel.

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Lots of hesitation when on heavy accel. (1/8)
9/30/15 10:03am

dads2vette

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Ash Fork, AZ - USA

Vette(s):
1981 Red Interior White exterior

Joined: 4/18/2007
Posts: 1053

This problem developed during a 650 miles traveled day. On my last fill up the car almost died when I accelerated up a ramp to the interstate. I babied it back and once it caught up to itself, fuel feed wise, the acceleration was fine. Happens quite often now after stopping either at a light or actually turning the car off.

Crate motor, nothing special. Edelbrock 1406. Does need to be re-timed. I have adjusted the distributor as it was barely chugging at lights...it was loose, chronic problem with this car. Engine compartment is HOT. Fuel line was very hot like holding a very hot cup of coffee and having to put it down right away.

Also, for those interested (Sarge), horrible gas mileage at altitude. Probably got less than 12 mpg for the part of the trip that was over 5000 feet, most of it was over 6000 and some over 7000. Didn't seem to loose get up and go but did use lots more fuel to get up.

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Yeah, I know, Shut up Dave.

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Re: Lots of hesitation when on heavy accel. (2/8)
9/30/15 12:09pm

ebo

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Holland Patent, NY - USA

Vette(s):
#1 *1980 White, Red interior 14,000 mile #2 *1980 Red, Oyster interior 93,000 miles Resto project car, rebuilt to 383 stroker

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Posts: 4421

Find a performance shop and rejet the carb.

ebo

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ebo

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Re: Lots of hesitation when on heavy accel. (3/8)
9/30/15 1:18pm

Adams' Apple

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Duncanville, TX - USA

Vette(s):
#1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas

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Sounds kinda like a vapor lock type issue to me. With the crappy ethanol fuels today, it can happen. Fuel boiling in the float bowls is common on the Edelbrocks when the engine compartment is hot like that. You might want to look into a carb insulator if you have room between the air cleaner and hood. It's also possible you just got some crappy fuel....might have some doo-doo in the tank now that is stopping up the fuel sock on the pickup tube.
Once you get settled at the new homestead, you might need to have the carb re-jetted for the dryer air out there, as Albo mentioned. Thumbs Up

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Re: Lots of hesitation when on heavy accel. (4/8)
9/30/15 4:59pm

dads2vette

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Ash Fork, AZ - USA

Vette(s):
1981 Red Interior White exterior

Joined: 4/18/2007
Posts: 1053

The folks that built the engine in the car are 20 minutes away. They have built thousands of motors so I'll give them a call. When it first happened, with the engine running a little hotter, the first thing I thought of was vapor lock. I didn't know about the jet replacement for dryer air. With only 13,000 miles on the car I didn't really think that would be an issue.

Thanks guys!

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Dave C..........My mantra: I can not be bought!! Long and short term leases available.

In the words of Zora Arkus-Duntov "Is your seat belt fastened? Alright, Let's go"

Yeah, I know, Shut up Dave.

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Re: Lots of hesitation when on heavy accel. (5/8)
9/30/15 6:43pm

F4Gary

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Grapevine, TX - USA

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1972 LT-1 convertible with factory air.

Joined: 8/26/2006
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Sounds to me like you need more advanced timing. I've never heard about re-jetting for dryer air, just for altitude. I do know that it needs to run richer for the 10% alcohol we have in our gas and re-jetting will accomplish that.

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Re: Lots of hesitation when on heavy accel. (6/8)
10/1/15 7:28am

ebo

Did it not start running hotter when you first started the trip as you drove up into the Blue Ridge?

I do not know if the rejetting will make the engine run cooler...... along with correct Timing......

But that seems to be something that needs to be done................

Goodluck and let us know when your Vetteman in the Mountain reality show starts!

ebo

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ebo

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Re: Lots of hesitation when on heavy accel. (7/8)
10/1/15 10:43am

dads2vette

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Ash Fork, AZ - USA

Vette(s):
1981 Red Interior White exterior

Joined: 4/18/2007
Posts: 1053

I had a day where the engine ran hotter and, as you suggested, I assumed it was from the "spirited" driving, made sense. The following day it had dropped to normal temps. Then after that i was putting on 550-650 miles a day in altitude and much increased heat.

I'm pretty sure it's a combination of everything. Considering the only real maintenance I've done to it since I left for Ebofest was change oil and check fluids I'm not surprised I have a little upkeep to perform. Heck, I did almost 6000 miles in 3 road trips this summer.

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Dave C..........My mantra: I can not be bought!! Long and short term leases available.

In the words of Zora Arkus-Duntov "Is your seat belt fastened? Alright, Let's go"

Yeah, I know, Shut up Dave.

Lifetime Member #192

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Re: Lots of hesitation when on heavy accel. (8/8)
10/3/15 9:32pm

73shark
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Overland Park, KS - USA

Vette(s):
1973 Orange Metallic Coupe (orig owner), L82, 4 spd (WR), PS, (A/C & PW (I installed from wrecked 73)), leather, AM/FM Stereo, ran with '65 FI unit earlier & will again some day.

Joined: 7/9/2003
Posts: 866

AFAIK, these cars are not compatible w/ E10 fuel. If you aren't using pure gas, then recommend adding Stabil for ethanol gas.

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1973 L-82 4 spd

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