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Discussion Starter · #1 ·
My '89 Eddie has 80k on it, runs great! c-6 & 351. Its pretty slugish though. My '95 has more power with 200k. I advanced the timing, replaced the fuel filter, added a k&n, plugs & wires, what next? The gas mileage is also horrible. WTF? It does smell a little rich, I put a new o2 sensor and did not fix the stink
 

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has no skidplate
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don't just throw parts at it pull the codes
realize you're comparing an 89 and a 95, that 6 years can be a biatch
also the transmissions are different, i dunno the difference in gearing but pretty sure it's there.
 

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Discussion Starter · #3 ·
We did pull the codes, all that came up was the O2 sensor. Other than that it says everything else is ok. I thought about the diffrence in years and gearing. It seems like when it hits 2nd it falls in its face. If I step on it at 60 it goes real well
 

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I advanced the timing, replaced the fuel filter, added a k&n, plugs & wires, what next? The gas mileage is also horrible. WTF? It does smell a little rich, I put a new o2 sensor and did not fix the stink
I don't know what a k&n is, but you may want to change your air filter too.
 

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I would address the O2 sensor code then clear codes, drive it and check them again just to make sure. You did both the KOEO and KOER codes right??

Also, what kind of plugs and wires did you use and did you replace the coil as well? What did you gap your plugs too and what did you advance your timing to? You might want to check out the sixlitre tune up thread (if you havent). It fully addesses doing a tune up with a larger gap and bumped timing.

I dont know the differences in gearing, but IMO anything with a 351 with only 80k should be in no way described as sluggish....? IMO, something aint rite.
 

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I never saw one, but my understanding is that before ford went to using a MAP sensor, they used something similar, and I understand that it has a filament that can get dirty, and cause the truck to run rich. I think it measures the air flow and sends info to the computer. Maybe it is called a MAF sensor. I am pretty sure that there is a low tech way to check it before replacement.

My '90 has a MAP sensor, I don't know when they made the change, maybe '89s have a MAF?

Come to think of it, a vacum leak could cause a faulty reading for a MAP sensor, and it *may* not throw a code.

and 1clean5.8 thanks about the air filter.
 

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Discussion Starter · #8 ·
I dig man, I have a mechanic that advanced the timing and it did make a difference, I think we set it at 10 past tdc. No pinging or anything, He knows his stuff for sure. I wonder if this thing has a cam and when the last owner put a new stock exaust on it, its getting choked. The original owner was a relative of the second owner and the 1rst guy that owned it did a valve job on it, when he passed his nephew inherited it and put a new exaust on it. With 80,000 on it why was a valve job done? I need more opinions
 

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In as far as mileage goes, the c-6 is not MPG friendly. Nearly bulletproof yes but it has no lockup feature and no OD. Add to that the fact that it is a power pig ( some figures are as high as 20% power loss through a c-6). I personally love a c-6 due to the fact that they're easy to rebuild and are very tough trannys. Another factor is the 351. Again not noted as the most MPG friendly engine ever built. Add a couple of tons of moving barn door ( Aerodynamically speaking). And it's not a very mileage happy recipe. As far as performance try adding a few more degrees of timing. Good rule of thumb is advance till it pings then back off two degrees.
Greg
 

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:popc1:
I never saw one, but my understanding is that before ford went to using a MAP sensor, they used something similar, and I understand that it has a filament that can get dirty, and cause the truck to run rich. I think it measures the air flow and sends info to the computer. Maybe it is called a MAF sensor. I am pretty sure that there is a low tech way to check it before replacement.

My '90 has a MAP sensor, I don't know when they made the change, maybe '89s have a MAF?

Come to think of it, a vacum leak could cause a faulty reading for a MAP sensor, and it *may* not throw a code.

and 1clean5.8 thanks about the air filter.
 

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Discussion Starter · #12 ·
Its not that im concerned about getting 15mpg, right now i get 10, that would be ok if it could stand up when I step on it, not that I expect alot., but something would be nice.
 

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Have you checked your fuel pressure?

I had power issues with mine since day one, it felt like I was running out of fuel--having to feather it to have ANY power. I couldn't get more than 32psi @ idle with the vacuum disconnected (adjustable fuel pressure regulator). It's supposed to have min. 30psi w/vacuum line connected, then 5psi more with it disconnected. I never had any codes and had crappy fuel mileage.

I R2 the fuel pump and I ended up with a whole new Bronco. Too soon to tell, but I think my mileage is a little better now (when I can keep my right foot out of it).
 

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chilly, you never said what brand/type of spark plug your using. I also suggest you double check the timing yourself with a light and make sure the spout connector is unplugged. you can go up to 12*btdc but should upgrade the coil when doing this. When was the last time the tranny was serviced?
 

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I dig man, I have a mechanic that advanced the timing and it did make a difference, I think we set it at 10 past tdc. No pinging or anything, He knows his stuff for sure. I wonder if this thing has a cam and when the last owner put a new stock exaust on it, its getting choked. The original owner was a relative of the second owner and the 1rst guy that owned it did a valve job on it, when he passed his nephew inherited it and put a new exaust on it. With 80,000 on it why was a valve job done? I need more opinions
Um , with the spout disconnected it is supposed to be set at 10 degrees BTDC. not after.

If you have it after, you wouldn't / should not run.

Probably had a valve cover leak, pulled the upper intake, noticed a nut loose on lower intake bolt, tightened nut and broke a bolt, probably was in the head, pulled head, noticed the valve margins were worn, redid valves. thats why I had to do mine.



:popc1:
 

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what gear ratio do you have? Anything less then 4:10 is gutless especially if you have 33s
 

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10 past TDC isnt that stock???? try some seafoam compresion check and yes check for a vac leak they could cause a shit load of head ackes
 
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