Ford F150 - 92-4.9 with possible power issues?

iceisasolid

Hi All,

I have been reading through the forum and have learned a few things. I really like the windshield wiper switch resurrection (Thanks!).

I have had my 6 cyl for about 4 years now and have often wondered why I don't have the torque that I have read so much about with the 6 cyl. I was recently towing (1st time) about 500 lbs in a trailer and noticed that it was bogging down and I really needed to ease off the clutch or it would start very hard and stall. As I have paid more attention to it, I have been easing off the clutch all the time or it stalls, it is just more pronounced with a load.

I have a flowmaster 40, K&N FIPK, Accel wires, and a hot coil (the name escapes me). The engine runs well. It never misses and always starts. It was treated like a baby before I bought it at 89K miles and I have treated to Idaho's outdoors, alot. It has 156K miles on it. I change the oil regularly, have used sea foam a time or two. My clutch releases high and engages high (that is it engages and releases very near the native state of the clutch pedal arm). I have replaced the clutch once and it was much better (it was easier to push the clutch pedal arm and the clutch's engage/release was closer to the floorboard) and seemed to last about 1 week and then it was the same again,hard to push down. It does not seem to slip. I also cannot start from 2nd gear as it stalls if I don't baby the clutch.

Fuel milage is about 13/15-20 depending on driving speeds (65 v 75)

I think that my rear differential is a 3.x5?

Any ideas?

Thank you,

Manny

rikard · Posted: Thu Sep 04, 2008 7:13 pm Post subject:

My 94 4x2 F150 5spd (Mazda) has the 3.55 gears and I average about 18 mpg in mixed driving and while not the best gearbox in the world the ratios seem pretty good for commuting and light hauling. I can start off on level ground in 2nd and only use fifth to hold speed on the highway if I'm hauling anything over a 1,000 lbs. It's on its second clutch and shows 188,000 on the dash.
The 300 seems to have a lot of holding power climbing hills. I had an older truck with a 302 auto 3.55 ratio and it accelerated better but required more rpm to climb the same hills.
Most of the F150s with the 300 seem to have the 3.08 or 3.55 gears. There should be a sticker on the drivers side door jamb that will ID what trans and rear axle ratio were installed by Ford.
When the previous owner replaced the clutch he also replaced the slave cylinder and flushed the system. The hard clutch action could be low or contaminated fluid. The hydraulic system uses brake fluid which can attract moisture.
Check the computer for codes and the the engine for vacuum leaks.
good luck
rikard

iceisasolid · Posted: Wed Sep 10, 2008 6:12 pm Post subject:

I had to take it to the shop for a new power steering pump. I spoke with the Ford tech about power issues and lack of starting power. He suggested that it was due to the 3.55 gearing. He thinks that the truck runs very well. He did suggest changing the slave cylinder as it is leaking. There is also a oil pain gasket leak.

I did ask him to pull codes today and see what comes up. no answer just yet. I do have 31's on the rims, stock height, but it didn't seem to be doing better with the stock tire size.

Any additional advice?

iceisasolid · Posted: Mon Sep 22, 2008 5:17 pm Post subject:

no codes when checked. I changed the plugs, cap, rotor, and cleaned the K&N FIPK. Drives better but again, not really impressive. I only have had a 90 2wd longbed 302 eod for comparison. It has better acceleration. I guess this is the case of it ain't broke... Thanks for the input.

crash-harris · Posted: Mon Sep 22, 2008 6:29 pm Post subject:

You should have no power problems with 3.55 gears, it would actually make towing easier, even with 31's. My 300 has over 275,000 and I can take off in 2nd just fine with the 5-speed Mazda and 3.08 rear gears. 3.08 gears and 28" tires produces the same results as 3.55 gears and 33" tires, so you should have plenty of power.

It does sound like it may be due to the slave cylinder and the fluid. Get some DOT 3 brake fluid (or DOT 3 Synthedic) and bleed the system undil the fluid runs clear. Be sure to remove the large diaphram that is inside the cap on the master! if there isn't something big attached to the cap when yo remove it then it's still in there. Just pull it out before you start or you will bleed the system dry.

rikard · Posted: Mon Sep 22, 2008 6:46 pm Post subject:

The last time I posted I had 3.55 gears and now I have 3.08s. As a daily commuter the 3.08s are better but I would change them out for the 3.55s if I was hauling much over 3000 lbs. I think the 300s low rpm torque could handle the load but first and reverse would be a bit too high with a stick.

regards
rikard