Slightly Rougher Ride at a Quarter Tank
#1
Slightly Rougher Ride at a Quarter Tank
I've never driven to the point of the fuel light coming on, but I do notice the engine seems to work just a little harder than normal when it gets to a quarter tank. Any reason for that? Already put in a fuel injector cleaner at fill up once.
Should I check my fuel injectors, physically and clean them?
I've already changed the fuel filter--which needed changing pretty bad.
OR maybe it's all in my head and really nothing is wrong. I've read these trucks are tempermental, maybe mine is just a little too bitchy.
Should I check my fuel injectors, physically and clean them?
I've already changed the fuel filter--which needed changing pretty bad.
OR maybe it's all in my head and really nothing is wrong. I've read these trucks are tempermental, maybe mine is just a little too bitchy.
#2
Get a pressure gauge, and measure pressure on the fuel rail (passenger side, looks like a tire valve). 32-34 PSI expected. Pumps are cooled by the liquid that surrounds them. At low fuel level (only $30 left in the tank) the old pump could be warmed up slighty, and starting to sieze up. Check pressure when running rough, and again when you limp into gas station and pay the hose bandits.
#3
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#9
Follow Up
Well...
I checked the valve running along the fuel rail this past weekend, when I had a full tank and a fuel injector cleaner in it (second time). The pressure according to a digital gauge was 35 psi.
Not trusting the reading, I decided to lift the cargo carpet and begin the arduous task of prepping a for a new fuel pump or fuel assembly. to my surprise I found this:
THe only rust was around the screws.
Today, I bought a tire pressure gauge, yes, Harbor Freight—whatever, it was $6. This time I wanted to test against the initial full tank reading.
I had less than half a tank—approaching a quarter maybe at a quater of fuel (again, feeling the car running a little rough).
This tire gauge confirmed an acceptable psi, albeit, two different instrument-type readings. Yet, I'm almost confident I'll get the same reading with the tire gauge at a full tank. This would naturally lead me to hypothesize the fuel pressure is good and the pump runs fine.
However, being that the fuel assembly--while looking clean and non-brittle on all connections--seems to work, could the pump still be dying? Or, should I start to focus on something else?
I should also mention that this "rough" feeling I get from the engine seems to emanate under and around me (US, left driver side). I can feel it in the steering wheel. And it happens when I tend to left off the gas and coast to a rolling stop or slow down.
Cel light also came on P0446.
I checked the valve running along the fuel rail this past weekend, when I had a full tank and a fuel injector cleaner in it (second time). The pressure according to a digital gauge was 35 psi.
Not trusting the reading, I decided to lift the cargo carpet and begin the arduous task of prepping a for a new fuel pump or fuel assembly. to my surprise I found this:
THe only rust was around the screws.
Today, I bought a tire pressure gauge, yes, Harbor Freight—whatever, it was $6. This time I wanted to test against the initial full tank reading.
I had less than half a tank—approaching a quarter maybe at a quater of fuel (again, feeling the car running a little rough).
This tire gauge confirmed an acceptable psi, albeit, two different instrument-type readings. Yet, I'm almost confident I'll get the same reading with the tire gauge at a full tank. This would naturally lead me to hypothesize the fuel pressure is good and the pump runs fine.
However, being that the fuel assembly--while looking clean and non-brittle on all connections--seems to work, could the pump still be dying? Or, should I start to focus on something else?
I should also mention that this "rough" feeling I get from the engine seems to emanate under and around me (US, left driver side). I can feel it in the steering wheel. And it happens when I tend to left off the gas and coast to a rolling stop or slow down.
Cel light also came on P0446.
Last edited by 120proof; 08-28-2013 at 08:09 AM.
#10
Evaporative emissions, probably a failed purge valve on the canister.
You sure it's a P0446? Anyways the P04XX codes are for the evap system and if it's flooding the engine with fumes, sucking the fuel tank in, or just not working your truck would run rough. Seriously, good job getting that far in 9 posts. Now you just need to fix it.
I would check the valve, canister and tank for obvious damage to pipes, connections, mud, bugs and that sort of thing. Go through the system and fix what's obvious and see if the light goes out. Look at your fuel tank the next time the truck is running rough, look for it sucking the sides in. Open your fuel cap as well to see if air is rushing in or out. Keep posting what you find.
You sure it's a P0446? Anyways the P04XX codes are for the evap system and if it's flooding the engine with fumes, sucking the fuel tank in, or just not working your truck would run rough. Seriously, good job getting that far in 9 posts. Now you just need to fix it.
I would check the valve, canister and tank for obvious damage to pipes, connections, mud, bugs and that sort of thing. Go through the system and fix what's obvious and see if the light goes out. Look at your fuel tank the next time the truck is running rough, look for it sucking the sides in. Open your fuel cap as well to see if air is rushing in or out. Keep posting what you find.