New Motor Problems

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Nov 5, 2005 | 06:47 PM

bmlawson

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New Motor 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 | 08:53 PM

Kemicalburns

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From: Bend,OR

who did you buy the motor from. why did you adjust the idle. efi motors have preset idle so that should not be messed with. the timing should be at 10*btdc with spout connector removed.

Nov 5, 2005 | 11:53 PM

bmlawson

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built the motor myself. the motor sounded like it needed to idle a little higher. i'll be checking the timing tomorrow and putting the idle back to stock

Nov 10, 2005 | 08:43 AM

fulie70

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Is this a speed density truck? If so unplugging the vacuum line from the map sensor will cause the engine to "lope".

Nov 10, 2005 | 09:44 AM

Kemicalburns

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From: Bend,OR

that idle screw should never be moved just to let you know. the computer controls those things . have you scanned for codes. go here www.fordfuelinjection.com