Heya guys.

I have a 1999 4.6L truck, 112k miles, that has developed a stumble that isn't attributable to the ignition, does not throw a code (despite being very bad at times), and has reduced greatly by close-interval uses of fuel injector cleaners (which surprises me, because I normally DO use a quality fuel injector cleaner every 3000 miles, plus a new fuel filter).

It's live-able, for now, but it's still there.

For the cost of a new set of 19 lb. injectors, I'm willing to buy them.

My question is about these injectors. Despite many of us getting 200k + miles out of the stock ones, how do old injectors wear? Does their electric-induced timing become poorer, or their parts stick (pintles?), or what?

Will a new set, specifically an "aftermarket" set like those from Summit Racing, be an improvement over the OEM ones at higher miles?

No, I'm not looking for the upgrades, the larger injectors, nor mega-horsepower. I'm just looking for some experienced commentary about what a new set of Accel fuel injectors might do for a truck.

Accel claims an "improvement" is possible with their claim that "Accel Performance fuel injectors provide precise control of fuel delivery and atomization for increased power, improved throttle response, and better fuel economy. Accel fuel injectors feature either a high or low-impedance design to function properly with your vehicle's ECU. These injectors also utilize a precision-ground, Bosch-style pintle design to produce a wide-angle conical spray pattern for ultra-fine fuel atomization and improved burn efficiency. Accel fuel injectors come complete and ready for installation with precision-molded O-rings and fine-mesh fuel strainers."

so... what's the real truth?

Thanks!

 

The new ones will give better performance over the old stockers because they are clean and everything moved freely.
I would go with the Summit brand myself in your case. There parts are name brand with the Summit name on them.
As far as failure, yes it can be a sticky pintles and the coil winding that could deteriorate and intermittantly open causing no movement and no fuel.
The stock injectors also use the Bosch style pintles so no big benefit there on the Accels. I wouldn't pay the extra money for them. My 1st. choice would be the Summit brand, then if I wanted a better brand name, then I would opt for the FRPP set. They are OEM quality and would work fine as well.

 

I seem to recall Summit sold the Ford Racing ones as well - and for something under $300, too.

Out of the Summit or the Ford Racing, I'm not sure which you are suggesting overall. Actually, when I choose the options from Summit's online page, for a 1999 F-150 4.6L, it only gives me the option of the Accels - it doesn't show Summit's own brand of injectors at all.

Thanks again!

 

I would use the Summit brand.
They are not vehicle specific, which is why they didn't show up, I guess. 19lb should be the correct size.

 

Interesting - I'll look into them!

On the web page, they really don't describe them with the emphasis that Accel do. While I'm no fan of sales hype, I'd like to know more about them, and why Summit feels theirs are better than the competition.

This is just speculation, but you mentioned the coil windings deteriorating - I've had that rear heater-hose area leak twice, soaking the engine and the plug with once-rusty, the second time clean, radiator fluid/water. I'm willing to bet something back there got messed up... hope it isn't the wiring harness.

 

Another possibility is five-o motorsports. I've ordered from them before and was pleased with the experience and the product. www.fiveomotorsport.com

 

Do you have coil packs over the plugs? If so, consider replacing the rear two on the passenger side.. that heater hose leak can screw those up pretty well. Or at least try removing them, apply dielectric grease on the boot, reinstall and see what happens. Also examine it closely while you have it out... look for water strains and if found... it's probably bad.

I've seen these cause this exact problem and not set a check engine light. Good luck!

 

will the FRPP injectors make a difference without the FRPP (or other) fuel pump?

 

Only if your stock injectors are failing.