496 HO tune-up suggestions
#4
Gold Member

Joined: Jul 2008
Posts: 3,748
Likes: 869
From: Delray Beach, FL
You need to find a service manual. I dont think you need to do anything but plugs and oil changes up to almost 600 hours.
FWIW - To change the coils would be a fortune. I cant imagine they are cheap.
FWIW - To change the coils would be a fortune. I cant imagine they are cheap.
#7
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Joined: Jan 2014
Posts: 105
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From: Brunswick, Ohio
2001 Donzi 33 ZX engines has 450 hours, wires look to be ok no burn marks, just new plugs should be ok? How about rebuilding injectors port engine is down 500hp and has hard time getting on plane
#8
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Joined: Jul 2011
Posts: 9,594
Likes: 46
From: Ft. Worth TX
The biggest problem with 496 fuel injectors is from corrosion deposits because the internal fuel rails can become corroded. I do have the professional machine to test, flow test and clean fuel injectors professionally. 40 % of my business doing so is 496 fuel injectors from all over the USA, so I see a lot of them and the problems they can have. A lot of times its uneven flow testing results so deep cleaning and special ultra sonic cleaning along with back flushing the injectors properly really brings them back fully ---- 90 to 95 % most of the time after those process.
maintenance - flame arrestor cleaning perfectly clean, throttle body cleaning, IAC muffler min once per year, clean that cavity out - a lot of times it wise to change out the original IAC or least carry new one on hand along with its gasket NEVER reuse the IAC gasket - always install a brand new IAC gasket. Make sure the hose to the IAC from the throttle body area is NOT restricted
1 st GEN ign coils can be a fail point. First gen crank sensor is also a problem and can be an area to check for reduction of RPMs. You will need a scan tool to see if anything else is going on plus the indepth knowledge how to decipher the scanning results.
Fuel filters but not knowing your serial number you can have all different versions and vary from 2 to 3 fuel filters
Anti freeze is often an item missed and so are the end cap gaskets for the heat exchanger
maintenance - flame arrestor cleaning perfectly clean, throttle body cleaning, IAC muffler min once per year, clean that cavity out - a lot of times it wise to change out the original IAC or least carry new one on hand along with its gasket NEVER reuse the IAC gasket - always install a brand new IAC gasket. Make sure the hose to the IAC from the throttle body area is NOT restricted
1 st GEN ign coils can be a fail point. First gen crank sensor is also a problem and can be an area to check for reduction of RPMs. You will need a scan tool to see if anything else is going on plus the indepth knowledge how to decipher the scanning results.
Fuel filters but not knowing your serial number you can have all different versions and vary from 2 to 3 fuel filters
Anti freeze is often an item missed and so are the end cap gaskets for the heat exchanger
Last edited by BUP; 10-24-2016 at 08:25 PM.
#10
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Joined: Oct 2011
Posts: 92
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