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I just recently bought an '87 F150. It has the I6 4.9L. I don't know much about these engines, but to me it seems to be a little sluggish on the bottom end. When I hit the gas (full throttle or just a little bit) it takes it a second or two to raise the RPMs. Is this a common thing with the I6? I know this thing has to have some kind of power, i just seems like the throttle response is way too little. Anything i should be checking for?
Here's a list of things that made my fingers bleed yesterday:
New plugs
New wires
New Dist. Cap
New Rotor
New Air filter
New Air filter - filter
New P/S pump -OMG that sucked
New fuel filter
This I6 has 112000 miles on it too
What else should I be looking to change for a better throttle response?
Thanks for your help, If i need to put in more information, I'll do that for ya. Be checking this site when I get home at 8:00 EST.
Was the 87 EFI? If so that's just how they are. You hit the gas and it takes a little bit for them to do anything. You can buy a module that plugs in to the TPS that is supposed to give instant throttle response for around $90. Mine was always sluggish until I installed larger fuel injectors.
i think most of the problem is from the length of the intake runners, it takes time for the gush of air to go down em when ya stomp on the gas. Great for making torque, but it'll screw with reaction times (at least mine anyway). like silver said, there are ways to increase throttle response without a major change, i.e. bigger injectors, throttlebody, even cams and head porting will do their part.
thank you for your help. ill see about that module chip. sounds like a worth investment. how much should i be looking at for an injector upgrade and how hard are they to install?
My '95 is EFI and a 3.08 rear end. In first there is no sluggishness, but in higher gears it is a bit slow responding below 2000 rpm. At 2000 there is a nice power surge that carries up through the power band.
INLINE SIX POWER! '95 F150 XL
300 Cubic Inches of Low RPM Truck Torque! And twin-I-beams too!
"Drive a stick young man! There'll be time for automatics when you're old and unable."
If you go with new FMS injectors (which is what I recommend) you're probably looking at about $350 to convert to 19lb injectors unless you pay someone to do it. There are better places to spend that money if your truck is stock.
Thank you for the info on the injectors. I had no idea what type of price range they were in. I just had a diagnostic run on the engine. Looks like the PiP sensor is out, the EGR, and something else....forgot what it is, but it looks like i'm up to my ears in expenses! I did however find a set of rebuildable HUB's for under 200 dollars.