FuzzFace2 Posted June 21, 2020 Share Posted June 21, 2020 60 miles later... 11.5MPG. It was 60 miles of mostly country roads and small town commuting though... so not a fair test?And I thought my mid 14's was bad ouch! Now this was with the 300 / T18 trans / 2.75 gear stock size tires and staying 65 MPH for 30 miles to work and sometimes 45 to 50 MPH stop & go for 30 miles home on back roads. I now have a NP435 trans and added over drive and need to run a few tanks to see if over drive helped or hurt as I just got the truck back on the road. I have started to look into what it will take to lean the YFA carb out with the metering rod. When I rebuilt my carb a PO really made a mess of it, missing or wrong type (wood) screws and think they messed with the rod. The paper did not say what the setting should be for it but have since found on Youtube what it should be. Could this be your issue also? Dave ---- Link to comment Share on other sites More sharing options...
1986F150Six Posted June 22, 2020 Share Posted June 22, 2020 However, let's be realistic on what to expect on MPG. The best I've seen with any engine and an automatic is 14 MPG at 60 - 65 MPH. That was a 351W I built with an RV cam, ported heads, and a 2150 2bbl carb. And the gearing was 3.50 with a C6. But you have a 300 six w/an AOD and 3.08 gearing. At first blush you'd think much better MPG. But if you are just tooling around town with stop and go driving probably not as the stopping and starting kills economy. And you aren't getting into the top gears with those speeds. For some good gas mileage data, look at Matthew's report [he has a 300 with C6]: Search for: My 2019 Show Report + MPG Data Link to comment Share on other sites More sharing options...
RenoHuskerDu Posted June 22, 2020 Share Posted June 22, 2020 Put a pressure gauge on the fuel line to carb. Link to comment Share on other sites More sharing options...
FuzzFace2 Posted June 22, 2020 Share Posted June 22, 2020 However, let's be realistic on what to expect on MPG. The best I've seen with any engine and an automatic is 14 MPG at 60 - 65 MPH. That was a 351W I built with an RV cam, ported heads, and a 2150 2bbl carb. And the gearing was 3.50 with a C6. But you have a 300 six w/an AOD and 3.08 gearing. At first blush you'd think much better MPG. But if you are just tooling around town with stop and go driving probably not as the stopping and starting kills economy. And you aren't getting into the top gears with those speeds. For some good gas mileage data, look at Matthew's report [he has a 300 with C6]: Search for: My 2019 Show Report + MPG Data After taking my truck to work for the first time since the over drive install I can see it will be hard to do a comparison at 65MPH. When in OD the truck moves along at 70-73 MPH real easy at under 2000 RPM (more like 1800 RPM) . I have to work hard to keep it at 65 MPH in OD and was just over 1500 RPM Dave ---- Link to comment Share on other sites More sharing options...
1986F150Six Posted June 22, 2020 Share Posted June 22, 2020 However, let's be realistic on what to expect on MPG. The best I've seen with any engine and an automatic is 14 MPG at 60 - 65 MPH. That was a 351W I built with an RV cam, ported heads, and a 2150 2bbl carb. And the gearing was 3.50 with a C6. But you have a 300 six w/an AOD and 3.08 gearing. At first blush you'd think much better MPG. But if you are just tooling around town with stop and go driving probably not as the stopping and starting kills economy. And you aren't getting into the top gears with those speeds. For some good gas mileage data, look at Matthew's report [he has a 300 with C6]: Search for: My 2019 Show Report + MPG Data After taking my truck to work for the first time since the over drive install I can see it will be hard to do a comparison at 65MPH. When in OD the truck moves along at 70-73 MPH real easy at under 2000 RPM (more like 1800 RPM) . I have to work hard to keep it at 65 MPH in OD and was just over 1500 RPM Dave ---- My truck with 3.08 rear and 4 speed manual OD turns just over 1800 RPMs @ 65 MPH. My son's 1984 was "born" with 2.47 rear and 4 speed manual OD turned ~1450 RPMs @ 65 MPH and returned 26 mpg. Link to comment Share on other sites More sharing options...
Gary Lewis Posted June 22, 2020 Share Posted June 22, 2020 My son's 1984 was "born" with 2.47 rear and 4 speed manual OD turned ~1450 RPMs @ 65 MPH and returned 26 mpg. And he had to downshift if he even saw a hill? Link to comment Share on other sites More sharing options...
1986F150Six Posted June 22, 2020 Share Posted June 22, 2020 My son's 1984 was "born" with 2.47 rear and 4 speed manual OD turned ~1450 RPMs @ 65 MPH and returned 26 mpg. And he had to downshift if he even saw a hill? Sometimes, even before! No kidding, it would go to about 40 MPH in 1st and idled @ 8 MPH! Link to comment Share on other sites More sharing options...
ratdude747 Posted July 2, 2020 Author Share Posted July 2, 2020 Funny, I did some searching, and discovered I completely neglected my EGR system. My buddy suggested I do so when the manifold was off... "nah too expensive"... DOH! Pulled the valve, was dirty but wasn't jammed. However, I did a vacuum test with a syringe, and discovered it's leaking like a sieve. Probably a bad diaphragm... will replace. Edit: Found a killer deal on valves: https://www.ebay.com/itm/ford-egr-valve-Standard-Motor-Products-EGV-243-1983-86-trk-100-to-350-4-9-5-0/183724154657?epid=74452957&hash=item2ac6d01f21:g:DbUAAOSwvQdchXNR Beats $85 everywhere else! (and yes, I crossreferenced it to the calibration list, this is the right part) EGR valve came in awhile back. Installed it, no change in performance or fuel economy (got worse, but driving was mixed). Seems that it can't stay in OD when cruise controlled ever... readjusted the TV cable, no change. My bottom end at highway speed is just not there and once it kicks down on a hill, it will only go back into OD if I kill cruise, even if I go downhill. Same issue that I've been fighting... although looking at how much gas it's having to give it to maintain speed, no wonder (and also no wonder my economy is so crappy). I can assure that when driving out of cruise I'm giving similar amounts of throttle. While re-adjusting the TV cable I ran a KOEO test to run down the throttle kicker motor... got a fault 63 during self test. Seems my TPS isn't being seen any more. Need to test to see if it's a sensor issue (doubt it, TPS was replaced not long ago), a wiring issue, or a DOA ECU issue. I also ought to test the MAP sensor; even though it's passing self tests, It's the one sensor/device I've not done a direct measurement test on yet. Reason being my "nice" multimeter that can measure frequency lives at work, and I'm too forgetful to remember to bring it home to test such. Link to comment Share on other sites More sharing options...
ratdude747 Posted July 4, 2020 Author Share Posted July 4, 2020 EGR valve came in awhile back. Installed it, no change in performance or fuel economy (got worse, but driving was mixed). Seems that it can't stay in OD when cruise controlled ever... readjusted the TV cable, no change. My bottom end at highway speed is just not there and once it kicks down on a hill, it will only go back into OD if I kill cruise, even if I go downhill. Same issue that I've been fighting... although looking at how much gas it's having to give it to maintain speed, no wonder (and also no wonder my economy is so crappy). I can assure that when driving out of cruise I'm giving similar amounts of throttle. While re-adjusting the TV cable I ran a KOEO test to run down the throttle kicker motor... got a fault 63 during self test. Seems my TPS isn't being seen any more. Need to test to see if it's a sensor issue (doubt it, TPS was replaced not long ago), a wiring issue, or a DOA ECU issue. I also ought to test the MAP sensor; even though it's passing self tests, It's the one sensor/device I've not done a direct measurement test on yet. Reason being my "nice" multimeter that can measure frequency lives at work, and I'm too forgetful to remember to bring it home to test such. Tested the MAP sensor... came up as dead. Replaced it... also came up as dead; turns out my backprobe jb was junk. Upon retest both MAP sensors seemed to be working (slightly different readings, but only about 6-8Hz different), but since I had a new sensor, I decided to run it. Also verified that TPS signal is making it to the ECU connector (0.7V @ pre-start throttle motor position). Drove it some, no obvious changes. Did another KOEO test, now I'm getting code 22 (MAP out of range) in addition to 63 (TPS below threshold). I'm thinking the replacement ECU is a brick... Were these ECUs known to be this picky/finicky? Link to comment Share on other sites More sharing options...
ratdude747 Posted July 6, 2020 Author Share Posted July 6, 2020 Tested the MAP sensor... came up as dead. Replaced it... also came up as dead; turns out my backprobe jb was junk. Upon retest both MAP sensors seemed to be working (slightly different readings, but only about 6-8Hz different), but since I had a new sensor, I decided to run it. Also verified that TPS signal is making it to the ECU connector (0.7V @ pre-start throttle motor position). Drove it some, no obvious changes. Did another KOEO test, now I'm getting code 22 (MAP out of range) in addition to 63 (TPS below threshold). I'm thinking the replacement ECU is a brick... Were these ECUs known to be this picky/finicky? Installed the old computer. Drove it around (no obvious changes or issues), did a KOEO test. No faults. Noticed that the "new" ECU is missing screws and was poorly spray painted... I'm beginning to think that the only refurbishing the ECU received is the rattle can treatment... Considering seeking a warranty refund due to all the issues (TPS and MAP faults). Seeing if this helps, since I didn't find/fix the EGR and loose carb issues until after the ECU swap. --- Besides a float adjustment issue, are there any carb adjustments that could cause it to run too rich? When I rebuild the carb, I didn't replace or adjust the float... I don't think I measured the metering rod either. I'd think if the float was hanging open too long, I'd have found it by now. Just lookign for things I might have previously overlooked Link to comment Share on other sites More sharing options...
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