Loss of power... HELP!!!
 

Hello all... I just rebuilt the top of my 2000 7.4 MPI (Gen Vl)... she got new heads, lifters and exaust manifolds along with a huge list of small stuff that I just threw away and replaced as needed.

You should probably know that with old parts compression ranged from close to 90psi on the low side to 150psi on the high. After installing all parts I checked again and had 155-160psi in most with a couple of cylinders in the 170-180 range. At first I was very excited that this thing was gonna run real strong but so far no.

I get her all together and she basically started right up... she idles well and seems to be running strong but once I got out of the channel and tried to plane I noticed that she just didn't have power. Top end RPM should be 4600 to 4700 and I was barely able to make 4K. Plust she took forever to plane.

I am looking at a couple of different things and would love to hear any insight... Maybe I did not get the distributor in proper (although I would think she would not be running well a all if that happened). Crossed an ignition wire?... I would have all kinds of poping and a rough idle right? Fuel pressure is really good so that is out. What about the ignition timing... I followed the procedure in the book but something was not right... specs say 8 deg before TDC while computer put in service mode but the tab that is on my timing chain cover only has one mark that I have taken to be TDC on the #1 cylinder.

Anyway... I would love to hear thoughts from some of you. I have spent a good amount of money and time and was really hoping to feel a big difference.

Any advice will be greatly appreciated

Thanks.

Brian

I would bet on the timing being off.

I am pointing in that direction myself... anyone have any tips for me? I put the computer in service mode and it automatically stabilizes base timing and bring idle RPM up to 1200 (just like the book says) then all I can do is line up the timing mark on the harmonic balancer with the one mark that there is on the the tab on the timing chain cover. So either I am doing something wrong here or the distributor is a notch off... but wouldn't that be more noticable?

Would love some help on this....

Thanks.

Brian

Did you replace the timing chain? If you are getting a good timing number it wouldn't surprise me if you have the timing chain off a notch.

Did you ever get the noise pinpointed and fixed? (From your other thread)

Those two marks are for TDC. If your not using a dialback timing light you are running 0* timing.

Did not replace timing chain pachanga... engine was running strong before I pulled the heads so I did not change it. The noise I had happening was an exaust hose that was not completely clamped down... It was a silly mistake niceguy... but I am glad it is not some more serious. She runs and idles really good at the dock but when I get out and try to push her there is no power. I am going to look into the timing today... just a little stumped about the timing marks on the chain cover... there is only one notch sticking out with no other numbers as the book shows... I should have at least 8 to 10 degrees of movement in each direction and it does not. Also, possibly the distributor off a notch. We'll see....

Thanks guys.

Brian

Ahh... so is that the key Kennyo? A light that will dial back the timing for me... then I guess that would explain... that much off would starve her of a lot of power yes?

Thanks man... will see if I can get a hold of a better light.

Brian

So timing it was!!!! Thanks guys... still have some more adjustments but 1000% improvement just by advancing up the timing just a bit.

So far she is running pretty dang good!!!

Thanks again guys...

Have a great summer!!!

Do it with a light or you'll be back wanting to know why you have holes in your pistons!