Need Help With Engine Temp

Rearanger · Apr 19, 2015

01b3000ds said:
You'll never know if it was sensor data input or fuel formulation messing with your mileage

The fuel trim is unaffected after about 140F.

Earlier post:

"There is a "start enrichment" of the first second of engine rotation based on engine temp. Then there is an "after start enrichment" of the first 20 seconds of engine rotation proportional to engine temp. After the time out of the other enrichment stages there is "warm up enrichment" based on engine temp up to 140F after which the enrichment due to engine temp ceases."

This stat/temp thing has been a good learning exercise. If my low mileage is due to more alcohol in gas I'll find out. I usually always buy from same station/brand. I have a tank now from Shell. A rise in mpg and I'll try it again to verify. Not taking injectors out for a while.

Rearanger · Apr 21, 2015

Update:

Well how bout this! Last tank filled with Shell Gas and MPG went to 20.11,
best result in 6 or so tanks and about previous average before drop in mileage.

Latest tank filled with Sheetz, so we'll see on my next fill. Looks like Murphy (Walmart) added a little more alcohol - maybe. Sign says (like all stations) - "Up to 10%".

Still going to do injectors for fuel trim issue.

JP02XLT · Apr 22, 2015

Sounds like your going the right direction, the amount of alcohol in gasoline makes a huge difference in mileage, I consistently run a 75/25 mix of gasoline to E-85 in my truck, it helps out on octane a bit for the SC.

With the self compensating (stab in the dark) E-85 map that Ford built for the Flex Fuel vehicles I do not see a drop in mileage at that ratio. if I increase the E-85 content, my mileage goes south 2-3 gpm right away, but I do not notice it being any richer on the wideband, or any slower achieving 14.8 on the way to cruise speed, or a major difference in fuel consumption/hr on the Scangauge, but my mileage will definitely go down. I have even been diligent driving as easy as I could and still lost mileage with an increase in the E-85, so maybe you were seeing a strong winter blended fuel, you just never know.

JP02XLT

Rearanger · Apr 23, 2015

JP02XLT said:
Sounds like your going the right direction

I have been buying gas at Murphy for a number of years (5 cents off with card) as well through winters with no change in average mpg numbers. On the times I had purchased elsewhere there were consistent mpg numbers. "Winter grade" did not seem to come in play here in NC.

I will see how this tank of Sheetz works out. I will also contact Murphy to see if they did up the alcohol content. At one point BP did not add alcohol to it's regular grade but charged more. I calculated I was saving money by getting better gas mileage. BP has since only offered no alcohol for its midgrade where the price does not justify the extra MPG.

It may turn out that my fuel trims are not the cause but only a contributing factor, but I need to get the injectors done anyway to hopefully improve idle and correct trims. In the back of my head I was trying to figure how rich running injectors, corrected by fuel trim, was lowering my mpg.

stmitch · Apr 23, 2015

Cheaper gasoline (from places like Murphy) typically has less detergent, or none at all, which can reduce the efficiency of the fuel system over time, and allow carbon to build up more easily. This may explain at least some of the gradual drop in economy that you've seen.
As I'm sure you know, what you put in your tank can have impacts outside of just the octane rating, or the alcohol content.

Rearanger · Apr 24, 2015

stmitch said:
Cheaper gasoline (from places like Murphy) typically has less detergent, or none at all, which can reduce the efficiency of the fuel system over time,

I know people say that but there are only a few refineries in the U.S. Murphy may get it's gas from Shell or BP or who ever. I'd need proof that as the gas comes out the refinery spigot they cut off additives for Murphy.

01b3000ds · Apr 24, 2015

Right.
The refineries only make one type of gasoline. The distributors control what gets put in to satisfy legalities. The retailers decide what other special recipe stuff gets added to that.

North American Governments generally stipulate that regular 87 octane gasoline contain 10% Ethanol. That means 90% is the gasoline shipped by the refinery. But You, the end user, still pays for 100% gasoline, because that is how the retailer makes money.
Same for all those specially patented additives, that countless hours and billions of dollars of research have gone into, further diluting the gasoline with completely combustible stuff that may or may not improve emissions, mileage, useful lifespan of the engine etc etc. and yet you still pay for 100% gasoline.

It's a gov't supported and mandated abuse of the people. financial and mental abuse. But then again, it's their money you're using, so they might as well have some say in which of their fat cat friends benefit from you using it, right?

01b3000ds · Apr 24, 2015

pure-gas.org/index.jsp

I don't trust all of the listings on this site, but in My neck of the woods they're pretty close to the bullseye.

Here where I am, its govt mandated that 87 octane is E10, 89 octane is E5, and 91+ octane is a moving target, sometimes E0, sometimes E5 as well.

Rearanger · May 7, 2015

Rearanger said:
Update:

Well how bout this! Last tank filled with Shell Gas and MPG went to 20.11,
best result in 6 or so tanks and about previous average before drop in mileage.

Latest tank filled with Sheetz, so we'll see on my next fill. Looks like Murphy (Walmart) added a little more alcohol - maybe. Sign says (like all stations) - "Up to 10%".

Still going to do injectors for fuel trim issue.

This tank filled at Sheetz produced 18.96mpg. So I'm back to the reduced mpg that got me going on this thread. Right now can't say Shell gas is the answer as I have gotten 18's before, just not in a row. I'll also have to get multiple tanks to verify.

This tank filled again with Sheetz. This test takes a while because I get two weeks from fill up.

For now I'm removing injectors this weekend to send out for test/clean/re-test. Just got gas yesterday so it'll be a while to see if 1. fuel trim improves 2. mpg improves.

Kinda two tests going on. Anyone bored yet?

Rearanger · Jun 4, 2015

Been away for a couple of weeks. Sent the injectors to WitchHunter for cleaning. Received them back with report - see image

I was looking for a leaking injector or two to source my rich fuel trim on Bank1. None came back leaking on the before.

I did notice some black residue around the tips (ingested oil from PCV) after I removed them, but none seemed in the spray zone. I did brush clean them before sending out as WitchHunter requests that to keep their lab conditions uncontaminated. Maybe I cleaned something off that was causing a leak.

Not much improvement from before/after except in static and pulsed varience and there is improvement in pulsed flow. If anyone has experience on this then please comment.

I'll install and post on fuel trims.

Rearanger · Jun 12, 2015

Engine Temp and Fuel Trims

So I've installed the cleaned injectors, fuel trims are more even. Unfortunately my battery crapped out while the truck was sitting for two weeks. That wiped out my computer memory and I had to start over again on fuel trims.

I cleaned the tar like crud as noted in the previous post with carb cleaner and Q-tips. After assembly I did a test drive then hooked up a vac line to the intake plenum with a small on/off valve. I cracked the valve just a little and bubbled in CRC Motor cleaner which is supposed to dissolve those deposits. I only dipped the vac tube in the cleaner very briefly so as not to risk too much liquid at once and allowed each injection to clear through. Used about 6-8 ounces.

Of course that gave me a P0300 pending code that cleared and I drove the truck a while to flush through the cleaner as I was getting very rich negative fuel trims.

Idle fuel trims went to BNK1 - -7.0 and BNK2 - -4.7. I thought maybe there was solvent in the oil as to the higher trims. I did an oil change and now have the trims at -1.6 on both banks, but have noticed a -3.1 and -2.3 BNK1 & 2 respectively, so I may need some more running in and computer learning.

Idle smoothness did not improve, to my disappointment, but idle fuel trims are better and more balanced. Without feedback on others fuel trims it's hard to know what's normal.

As I discuss in the PCV thread:
http://www.therangerstation.com/forums/showthread.php?t=161366

I don't think oil vapors are a problem on this engine with fuel trims. I think the accumulation of oil in the intake is normal over the 78k miles I have on the truck. I will however do a once per year intake flush as described above, but only just before I need to do an oil change.

Truck is running great with no noticeable issues except for a little lumpy idle I'd like to fix, but don't know where to go.

Trouble with a scan gauge is - it can drive you nuts. I'm closing down the fuel trim page for the gas mileage page for a while. Switching to Shell gas to see if mileage improves.

alwaysFlOoReD · Jun 12, 2015

Thanks for the update.

Rearanger · Jul 10, 2015

Update

I finally had an idea that maybe the charcoal canister purge valve might be leaking and spilling fuel vapor into the intake to give me the negative fuel trim numbers at idle (slight rich run).

I took idle LTFTs with the valve connected and got my usual Bank1: -7.8 and Bank2: -5.5 I disconnected the intake manifold connection for the purge valve and plugged the manifold port, started the engine and observed that my LTFTs went to -3.9 Banks 1 and 2.

I vacuum tested the valve both on and off and found there is a slow leak. The valve is normally closed and there is a check valve on the canister intake port. The leak was through that check valve.

I guess the evap system never thought the leak was enough to trip a code but in any event I'm going to replace the valve and see how LTFTs settle out after some driving.

Rearanger · Nov 24, 2015

Thread Summation

Been a long time posting and this thread has gone on a long time.

I don't know if it has helped anyone but it has taught me some stuff.

Trying to find the cause of my lower mileage has boiled down to the gas as far as all the "solution" attempts I have made.

1. Understanding Engine Temp
2. The Effect of New Tires (They take time to break in)
3. Adding injector cleaner (useless)
4. PCV Inspection/Testing (nothing wrong with mine)
5. Professional Injector Clean (nice to do but no fix)
6. Replacing Leaking Evap Purge Valve (thought this was it - but no)
7. Buying Shell Gas - with 5 cent back card.

Following new tires my mileage consistently went down to 18 mpg then 17 mpg in 9 consecutive tanks - an event never observed before, and right after new tires. Nothing above really helped to any significant degree to return my mileage to previous levels.

It seems #7 above was the best answer, as my mileage has returned, but still not to pre-tire averages. Since switching to Shell I have two 20 mpg and five 19 mpg tanks. No 18 or 17 mpg. The number of 20 mpg is down enough to lower my historical mileage.

If anyone remembers, I was a consistent user of Walmart gas (5 cents off), and I got good mileage with it, until Dec 2014 into 2015. I had used Walmart in previous winters and never got any change in mileage. I think Walmart either intentionally added more ethanol or there was a mistake at the refinery.

For giggles I can now go back to Walmart and see if it returns my mileage to those poor numbers since I have a good data base for comparison.

The quest continues.

JP02XLT · Nov 27, 2015

Good info, glad you posted your results, I can tell you I see a dramatic drop in mileage when the weather starts to cool off. I buy gas from several locations due to the amount I travel and they are all pretty much the same, sometimes I will see a 19-20 mpg in the late fall / winter months but mostly I see 17-18, a mix of city / highway.

JP02XLT

Need Help With Engine Temp

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