MTKirk
Full Access Member
Pretty close to floored, though I can hit just over 70 on flats without wind if I need to pass someone.
First impression towing with 6.9 NA
- Thread starter Cubey
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frankenwrench
overkill is under rated!
So essentially I've got close to 8k in a truck that I've just lugged on? Possibly why the stock muffler I just cut off was full of soot? And it does consume oil. About a quart every thousand miles or so. Moreso during winter wen I let it sit and idle to warm up in the morning
Macrobb
Full Access Member
Your timing is retarded, and you may want to back out the fuel screw a flat if you are smoking much at WOT.
My guess is you'll have more power with it adjusted right, and maby a new set of injectors/ip if they are old.
Personally, I get annoyed dropping below 55 going up a 6% grade with 9,000lbs behind me... which is why I have a turbo on mine. Cranked up pump and turbo = power. Plain and simple.
My guess is you'll have more power with it adjusted right, and maby a new set of injectors/ip if they are old.
Personally, I get annoyed dropping below 55 going up a 6% grade with 9,000lbs behind me... which is why I have a turbo on mine. Cranked up pump and turbo = power. Plain and simple.
I wouldn’t say you lugged it per se, but you weren’t in the ideal rpm range for towing. You will have less air going through the engine at lower rpms but more fuel because of how these db2 pumps are with their fuel curve, that’s why you probaly noticed the excessive soot. Your oil consumption sounds normal for a new engine, most people report a good bit of consumption until the engine has a good amount of miles under it.
FordGuy100
Registered User
5k lbs will slow an IDI down pretty good, but it sounds like it wont go above 55 mph even on flat ground. There is something amiss there, I think.
Even without a timing light I'd advance the timing a little. Throw a new fuel filter on it. Perhaps try to test the lift pump fuel pressure and if low replace with a new one or an electric pump.
Even without a timing light I'd advance the timing a little. Throw a new fuel filter on it. Perhaps try to test the lift pump fuel pressure and if low replace with a new one or an electric pump.
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hoodshauler
Full Access Member
If you can’t get over 55 mph you definitely have something going on that needs to be resolved. I would start with timing and go from there but on flat ground you should be able to get that truck up to 65 mile an hour with no problem.
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Knuckledragger
blowing chunks and grabbing porcelain
Okay, I'll repeat what everyone else has said, check timing and work from there. I have the same rig, but with a rebuilt engine. It has no problem going 70-75 (no tach) unladen, towing is slow, but steady.
My problem, although infrequent, is that the engine creates so much torque that on a wet road it spins the tires way too easily. I have a donor positraction in another 85 truck out back, that swap will be happening soon.
My problem, although infrequent, is that the engine creates so much torque that on a wet road it spins the tires way too easily. I have a donor positraction in another 85 truck out back, that swap will be happening soon.
genscripter
Full Access Member
The OP's performance with a non turbo is pretty standard for mph. Before I turboed my van, pulling up a hill was 50mph max. It didn't matter if it was half throttle or full throttle... you only got 50mph out of it.
Now with my turbo and gearvender, I can easily pull up the California passes and grades at 70mph with a full load. I highly recommend getting a turbo it ap asap.
Your mpg is disconcerting though. You definitely need some tuning and maintenance. But once those are fixed up andyou want explore more eco mods, check out some of my eco projects: http://www.nickpisca.com/diesel/turbo/the-great-big-list-of-eco-mods-for-6-9-and-7-3-idi-vehicles/
Now with my turbo and gearvender, I can easily pull up the California passes and grades at 70mph with a full load. I highly recommend getting a turbo it ap asap.
Your mpg is disconcerting though. You definitely need some tuning and maintenance. But once those are fixed up andyou want explore more eco mods, check out some of my eco projects: http://www.nickpisca.com/diesel/turbo/the-great-big-list-of-eco-mods-for-6-9-and-7-3-idi-vehicles/
Day 3: That stretch of highway yesterday must have been more brutal than I thought. I filled this morning and yeah last (about 1/2) tank was about 10mpg with about 30% or more city. But one tank is too early to tell. Maybe the previous pump didn’t fill as much as this I’ve did.
Today, I had less issue staying at 55 on level roads. If i get with a lot of uphills with no down between, it makes it hard to actually build up any speed, showing me down to 40-45. about 200F was the max still.
Coming up a crazy grade to Heavener Runestone State Park in Oklahoma, I had to put it in first gear manually and crawl up the hill at 10-12mph. Speed limit was 15 anyway. Temp climbed to about 220F (100C) but I can’t blame it. It dropped back quick to 200 once we got up top. I use my old gps set to always show mph in the bottom left corner so that’s handy.
Today, I had less issue staying at 55 on level roads. If i get with a lot of uphills with no down between, it makes it hard to actually build up any speed, showing me down to 40-45. about 200F was the max still.
Coming up a crazy grade to Heavener Runestone State Park in Oklahoma, I had to put it in first gear manually and crawl up the hill at 10-12mph. Speed limit was 15 anyway. Temp climbed to about 220F (100C) but I can’t blame it. It dropped back quick to 200 once we got up top. I use my old gps set to always show mph in the bottom left corner so that’s handy.
Have you checked to see if your fan clutch spins freely? 6.9s generally run cooler but I wonder if that may be the issue that’s killing your mileage and hurting your performance.
FordGuy100
Registered User
Yeah you got something going on big time. Brakes dragging perhaps? I just google map hill climbed and it didn't look too awful steep, although I know there are some good hills over in that part of OK/AR.
Does the engine free rev normally. IE, put it in neutral and rev it up to the governor and hold it there and listen/feel how the engine is running (might want to do this in town, not in the park!). Does the truck have more power when its cold? You can always test out timing by running a 12v to the high idle advance to see if it helps out. If so, advancing timing will surely help.
Does the engine free rev normally. IE, put it in neutral and rev it up to the governor and hold it there and listen/feel how the engine is running (might want to do this in town, not in the park!). Does the truck have more power when its cold? You can always test out timing by running a 12v to the high idle advance to see if it helps out. If so, advancing timing will surely help.
Or, could it be something like @pelky350 had in his low boost thread. His throttle cable wasn’t giving 100% throttle when the pedal was on the floor.
With the engine off, have someone hold the throttle pedal to the floor, and then go move the throttle lever on the passenger side of the pump. See if you can move it farther from the idle position (toward the firewall if I remember). If you can push the lever farther than the pedal has moved it, you have an issue with the throttle cable.
If this is the case, when the pedal is pushed to the floor, the IP is only being commanded to 75 or 80%, or whatever less than WOT that your foot is requesting.
With the engine off, have someone hold the throttle pedal to the floor, and then go move the throttle lever on the passenger side of the pump. See if you can move it farther from the idle position (toward the firewall if I remember). If you can push the lever farther than the pedal has moved it, you have an issue with the throttle cable.
If this is the case, when the pedal is pushed to the floor, the IP is only being commanded to 75 or 80%, or whatever less than WOT that your foot is requesting.
It’s several hundred feet in 1/2 mile or less. Turn on terrain view.
Oh hell I forgot about that. My cold advance sensor is broken. Would that matter for full operating temps though?
It has the same power cold or warm.
Seems ok reving it in N. I do on cold mornings to help the C6s morning sickness.
Oh hell I forgot about that. My cold advance sensor is broken. Would that matter for full operating temps though?
It has the same power cold or warm.
Seems ok reving it in N. I do on cold mornings to help the C6s morning sickness.
How would it? Always being locked?
That’s right
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