Tech / Tech Articles

Mailbag: Fixing Fuel Pressure & Optimizing Fuel Economy

Got questions?

We’ve got the answers—Mondays when the Summit Racing tech department tackles your automotive-related conundrums. This week, we’re taking on engine hesitation and the poor fuel economy that’s so common in older trucks. 

From: Don Albrent, Jr. • Tomahawk, WI
Q: I own a 1991 Chevy K1500. I’ve rebuilt the engine and added an Edelbrock Performer-Plus cam and lifter kit, 2 ½-inch dual exhaust with Summit Competition mufflers, cold air intake, 160-degree thermostat, and a JET Performance Stage 2 off-road chip. The truck fires up fine and has a strong idle but when I step on the gas it sputters and hesitates. I thought it was an electrical issue so I replaced the coil, wires, and plugs. Any theories on what’s causing the hesitation?

A: It sounds like a potential fuel problem. You could be running lean or the pressure may be too low. Your upgrades demand more fuel to run at max performance, so the engine hesitates under throttle when there isn’t enough gas supplied. You can optimize your fuel delivery with an adjustable TBI billet fuel pressure regulator from JET Performance. It will precisely meter your truck’s fuel supply and improve throttle response. Be sure to keep an eye on your fuel pressure as well—Summit Racing has a large selection of universal gauges.

From: Eddie Merrill • Allen, TX
Q: I have a 1985 F-150 4WD with a 351W high output engine. I added a low-rpm torque camshaft and an Edelbrock Performer intake, and I am still running the stock 4160 Holley four-barrel carburetor. This setup seems to perform pretty well but the fuel mileage isn’t very good. I get about 11 miles per gallon on a good day. Do you have any suggestions for improving my fuel economy?

A: You’re certainly not alone in the search for better fuel economy. Older trucks are notorious for poor fuel mileage, but with a little tuning and part swapping you could see an improvement. First, we would recommend our Summit Racing Street & Strip Multi-Spark Digital Capacitive Discharge Ignition (SUM-850610). This high-output box uses cutting-edge microprocessor controls to create hot, consistent sparks for performance throughout the powerband.

Secondly, you’ll need a set of spiral wound ignition wires. They’ll minimize voltage loss and deliver spark right where you want it, when you want it! Once your ignition setup is in order, add the SA Design Super Tuning and Modifying Holley Carburetors Manual (SAD-SA08)to your horsepower library. This 144-page manual is full of custom tuning options so you get the most out of your stock 4160 Holley four-barrel carburetor.

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