New Motor install Problems.

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Nov 5, 2005 | 06:40 PM

bmlawson

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New Motor install Problems.

Hello everyone. I have an 89 ford f-250. I just purchased a rebuilt 351who motor. The motor iss bored 30-over and I added 1.7 roller rockers and a roller timing chain. The problems I am having are as follows. The truck seems to lope when warmed up. Now I know someone will ask if I installed a new cam and the answer is no. The cam is the stock cam for the roller 351w block. It almost sounds like it's missing real bad, because when it starts to make that noise the whol;e truck will start to rock. Do you guys believe it could be that the timing for an 89 351w isn't the same as the timing for this motor? It also only started to do this after i adjusted the idle up some. So any advice would be helpful. Also could this be caused by the emmissions not being installed on the motor?

Thanks, Matt

Nov 5, 2005 | 09:32 PM

frederic

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Joined: Oct 2003

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From: New Jersey

Sure, the timing could be off. Loosen the dizzy *slightly* while it's running, and shift it a few degrees each way and see if it idles better. Just mark where it is now with a sharpie before moving it, so you can put it back to the same spot.

10 degrees with the SPOUT plug removed, correct?

Nov 5, 2005 | 11:24 PM

MRL123

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Joined: Oct 2004

Posts: 371

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From: Wetaskiwin, Alberta

Another possibility that you should probably try to eliminate is a vacum leak. This will also cause your engine to lope like you have a very exotic cam in there. Try spraying some WD40 or similar around the engine bay and listen for the idle to change up when you hit a specific area with the spray. You can also try the same technique with propane if you have sufficient "cajones" to try it. Personally, I stick with the WD.

You could also try a compression test and a leak down test - just to make sure that your pistons are all pulling the load equally.

Cheers!

Mike