 misfiring at midrange rpm, engine diagnosis? |
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| timofly |
 Apr 2 2010, 05:02 PM
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#1
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Member  Group: Members Posts: 164 Joined: 21-February 09 From: VA Member No.: 10,082 Region Association: MidAtlantic Region  |
Puzzler?
1974 2.0 just out of extensive (and expensive) overhaul and mild juicing. We retained the FI. New valves, 96mm cyls and pistons, performance lifters, street cam, new distributor cap and on and on new this and that everywhere. You get the idea. The car starts and idles OK, but will not run smoothly between idle and wide open throttle. It is bucking and kicking like mad unless the throttle is floored, then it takes off like a shot. Shop that built the engine can't seem to find the problem. Any ideas out there? T |
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Replies(1 - 2)
| rhcb914 |
Apr 2 2010, 05:37 PM
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member Group: Members Posts: 358 Joined: 3-February 04 From: Boston, MA Member No.: 1,626 |
When you say street cam, exactly what cam did you use?
There are very few mild performance cams that work with stock FI. Web cam 73, Jake's FI cam, Fat Performance 440HP and maybe a couple more. |
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| r_towle |
Apr 2 2010, 05:53 PM
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#3
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Custom Member Group: Members Posts: 24,576 Joined: 9-January 03 From: Taxachusetts Member No.: 124 Region Association: North East States 
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You will need to tune the MPS. Your part load is no longer correct due to the larger displacement and if you have to much overlap on the camshaft....it may never tune out.
Send me a PM if you dont want to share...otherwise man up and tell us what camshaft is in there, what "performance lifters" you used...what rocker arms you used, size of valve etc. It may be fixable but you will need to tune it. Rich |
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