I have a 95 Ford F350 with a 460 it has about 102,000 miles on it. The motor needs a rebuild but I'm hoping to wait for warmer weather. The truck runs fairly good until it warms up. After it gets to operating temp the engine starts to sputter a bit when you step on the gas. It runs fine at an idle, it's only when you start moving along. It's been tuned up recently. No crossed wires or anything like that. Any other idea's ?

Thanks

 

I think you need a tuneup, not a rebuild. The 460 will live along time even when neglected, but I have seen a few with bad cams from using too thick of oil in cold weather.

 

It probably wouldn't hurt to run diags and see if there are any stored codes in the ECU- even if the "check engine" light isn't on.

Sounds kind of like you have either a fuel-delivery or emissions related problem. When was the fuel filter changed last? Also, I learned the hard way that just because you have new plugs & wires doesn't mean they are "good". I have purchased a couple of sets of wires in which one (or more) had problems.

 

The fuel filter was changed abour 6 months ago. I also had to change the fuel rail due to a pin hole leak at the pressure regulator eariler this year. I used new o-rings on the injectors. I had the upper intake manifold off to replace the rail. Could a vacumm leak cause this sputter. I tried the carb spray test but did not see a noticeable difference in rpm. I'm open to comments and suggestions.

Thanks
John

 

IAC motor or maybe TPS sensor?

doubtful you need rebuild at that mileage.

 

Where and what is the function of the IAC motor ? I did a compression check on the cylinders and they were all around 90 psi. They are suppose to be around 150 I guess. It definately lacks power and uses some oil, but it's not completely dead yet. I also put a bit of clean oil in the cylinders and re-did the compression check. It went up to about 140 psi. Sounds like worn piston rings. But it's cold and snowy here and this is no time to do a motor swap. I just want to make it run decent for a few more months and then tackle the engine change.

thanks
john

 

a vacuum leak could definately cause these problems. also check those stored codes. i would be looking for a coolant temp sensor code or maybe an oxygen sensor related code.
how is your exhaust? does it sound any different than normal? a blown out cat or muffler could cause a loss of power.

 

I believe all the posts are good suggestions. I'll only add that scan tools (code readers) for these older EFI motors are very cheap (I got mine for $28 a few years ago), and they come with a book that explains how to get the codes and what each means. This would probably save you a lot of headaches and unnecessary new parts.

My 2cents - Oxygen sensor, vacuum leak or something with the EGR.