Carb power problems????
04-24-2017, 08:56 PM
#1
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Carb power problems????
So here's my issue my 88 iroc z28 automatic is stuttering and not advancing past 4000 rpm in drive or overdrive with full throttle however first and second Wil both run up to 7000 with ease any thoughts I have switched from tpi to a 600 Holley with vacuum secondary I'm very confused by this
04-25-2017, 08:35 AM
#4
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Re: Carb power problems????
When you downgraded to a carb did you replace the factory distributor? What did you do to reduce fuel pressure?
04-25-2017, 09:01 AM
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04-25-2017, 01:11 PM
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04-25-2017, 02:44 PM
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Re: Carb power problems????
also should mention this issue just started this week has been running fine for months every now and then I noticed a stuttering at 4000rpm in drive but the it would proceed now it's like hitting a wall every time but only in 3rd and 4th gear no issues at all in 1st and 2nd could it be the vacuum secondary malfunctioning? Also I noticed a small spot on 1 plug wire where it had bumped up beside the header
04-25-2017, 02:50 PM
#9
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Re: Carb power problems????
IF you are only having the problem in first and second gear then the problem points towards a trans issue.
04-25-2017, 03:05 PM
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04-25-2017, 08:28 PM
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Car: 1990 IROC
Engine: Rebuilt L98 with H/C/I/Carb
Transmission: TH350 with ATI Treemaster
Axle/Gears: 7.5 with 4.10's
Re: Carb power problems????
Could be the HEI module going south. They tend to act weird right before they die completely. Or, the full-time 12v power wire going to the HEI. If the voltage isn't the full 12v, goofy things can happen.
04-26-2017, 02:16 AM
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Car: 91 Firebird
Re: Carb power problems????
Move your fuel pressure up .5 psi a time and see if that helps. Sounds like you are running out of gas. I had a similar issue with my car when I got it. The POS did a V8 swap and had the fuel lines routed wrong with the return line before the regulator. Fuel pressure wouldn't stay high. Put in a AFPR with a return on it, and haven't had that issue. However, I though Holleys needed 6-7.5 psi. Not sure though as I haven't had a Holley.
04-26-2017, 03:13 AM
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Car: 84 TA orig. 305 LG4 "H" E4ME
Engine: 334 SBC - stroked 305 M4ME Q-Jet
Transmission: upgraded 700R4 3200 stall
Axle/Gears: 10bolt 4.10 Posi w Lakewood TA Bars
Re: Carb power problems????
Is his torque converter locked while in D and OD?
04-30-2017, 11:16 AM
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05-01-2017, 02:24 PM
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Car: 82 Berlinetta/57 Bel Air
Engine: LS1/LQ4
Transmission: 4L60E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
Problem band-aided. 5 psi is plenty for a Holley, 7 is max (so you don't overwhelm the needle/seat). Carbs don't operate on fuel pressure, they operate on fuel supply. Pressure only insures the fuel can overcome acceleration and keep fuel flowing up to the floats.
You didn't answer my question. So I repeat: Is the factory in-tank pump still operating? If not, did you remove it from the tank?
You didn't answer my question. So I repeat: Is the factory in-tank pump still operating? If not, did you remove it from the tank?
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