engine woes

[t_ball]

i just bought a sweet (so i thought) 1997 sho,the motor idles good, but under any accelaration it actually slows down???? i was told i could have a cam problem, but this is my first 4 cam motor and dont know where to start, it hits on all 8 and compression is 125 lbs. any ideas.

 

[JC]

t-ball, do a search on this forum regarding the v8 SHO's and their cam failures. It is a big issue with the GEN 3 SHO's, and has even sparked up lawsuits against ford

 

[JC]

Basically, your gonna have to get your cams welded.. go to www.v8sho.com, there is more info there. I just did the search here on this site and theres over 130 threads when you type in "cam failure"... good luck

 

[f150fan]

It's not your cams. If it were your cams, the motor would be making an awful noise like it had no oil...that is if the motor would even run. The fact that you have the same compression on all 8 guarentee's its not a cam failure as a failed cam would leave some valves open due to the cam not moving which would result in lower compression. Give us more details? What do you mean it slows down? Under full throttle? Does it "hiccup"?

 

[wild01ride]

As the above have mentioned, the cam issue is priority #1. It doesn't have anything to do with being a 4-cam motor, it is an inherent problem with the manufacture of the camshafts themselves.

2nd, there's a good chance that your poor performance is due to sticking secondary butterfly valves. There is also MUCH written about this problem on V8SHO.com (you'll find that website to be very valuable in maintaining and enjoying your new treasure!). Basically, there is a set of small throttle plate-like butterflies in the lower intake manifold that are actuated at and above 3400RPM. These buttefly valves see a lot of residual fuel vapor throughout their lives and they and the walls that they mate against get gummed up over time. All it takes to remedy this problem is to remove the intake components until you get down to the lower intake (the portion of the intake manifold that contains 16 small openings and mates directly to the top of the engine). If you are even a recreational mechanic you should be able to do this. Once removed, a liberal amount of carb cleaner or similar along with a scouring pad or similar will clean them right up.
Welcome to an elite ownership- once your cams are welded, I think you will surely enjoy your new gem!

 

[f150fan]

To add to the butterfly comments above, it could be the motor (IMRC motor) that actuates the "Secondary Butterflies" It is easy to check this and I would do this first before tearing down to clean butterflies. There is a cable that runs along the front head to the secondarys. Do a search on v8sho.com and there is pictures that show this. Good luck

 

[stephen newberg]

And finally, it could also be the actuator cable, which apparently sometimes frays and breaks. But it does sound mainly like the butterfly problem in one way or another.

And do get those cams looked into right away. Check V8SHO.com for more information.

pax, smn

 

[venom]

Many people are talking about the IMR or IMRC AKA "Butterflies" in this thread, but we need to know one thing first...

Is your "Service Engine Soon" light on?

If not then your problem IS NOT your IMRC or any of it's associated parts.

If it is then go someplace to pull the code (autozone will tell you the code(s) in memory for free). Once you have that information then return to us with the codes.

If no light... I'd have to be thinking fuel. Check fuel pressure, it is probably past due for a fuel filter anyway. Or possibly plugged up exhaust.

t_ball:
i just bought a sweet (so i thought) 1997 sho,the motor idles good, but under any accelaration it actually slows down???? i was told i could have a cam problem, but this is my first 4 cam motor and dont know where to start, it hits on all 8 and compression is 125 lbs. any ideas.

 

[SHOZ123]

If the cable breaks on the IRMC the SES light will not light. BTDT