89 vette
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89 vette
hey everyone , I have a problem with my 89 vette . engine is bored .030 , flattop pistons with Teflon skirts , cam upgraded .030 more lift intake and exhaust , muffler eliminators , advanced 2 degrees on crank sprocket , bosch 24 lb 4 jet injectors . runs great , but long after it gets warmed up it acts like throttle is disconnected . it shuts down to an idle and keeps running until you floor it and it backfires and stalls . it will start right back up and run good for a few miles then do it all over again . new fuel pump , filter , plugs wires cap and rotor . I get no computer error codes . any ideas ?
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Joined: Sep 2004
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From: Mission Viejo CA
What do you mean by "advanced 2 degrees on crank sprocket"? 2 degrees BTC, or 2 + 6 degrees BTC, since standard is 6 degrees? I'm presuming you're talking about the harmonic damper.
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89 vette
when I rebuilt the engine , the crank timing chain sprocket had 3 keyway slots . I used the 2 degree advance slot , and I ran down the road with fuel pressure gauge attached . 42lbs at idle , 35 lbs running down the road and under acceleration
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From: Kingman AZ
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Test and diagnose first. Don't guess. Use the FSM flow charts and go step by step to find your problem.
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89 vette
what is icm and fsm flow chart ? I am a mechanic , but not too familiar with tuned port and computer systems . most of my cars were gto and 76 , 71 , 69 65 60 corvettes . I don't know condition of cat converter , but have good exhaust flow from pipes and o2 sensor is new . i'm wondering if a new fuel pump can overheat system stays pressurized for a long time after engine is shut off
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no , never ran right , but mostly small stuff like throttle position sensor , etc . replaced distributor with new gm one . car sat for 5 years outside in florida elements , but fortunately interior was good and dry with no musty odor . it was bought by me with blown head gasket 2 yrs ago
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if your holding fuel pressure that is good what pressure? fsm factory service manual.
ohm the injectors hot and cold and let us know.
is it running smooth or rough.
ohm the injectors hot and cold and let us know.
is it running smooth or rough.
Last edited by antfarmer2; Dec 3, 2015 at 06:34 PM.
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Safety Car
Joined: Sep 2004
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From: Mission Viejo CA
icm = Ignition Control Module (inside distributor)
fsm = Factory Service/ Shop Manual. Outstanding. Don't bother with Haynes or Chilton joke books.
It's excellent that fuel pressure is maintained! Pump can't overheat system. Since you're a mechanic, what is your theory on this question? Strange question in my opinion.
Is your new dist. the correct one for an '89 Corvette? Generic GM won't cut it! (No centrifugal weights and no vac advance.)
fsm = Factory Service/ Shop Manual. Outstanding. Don't bother with Haynes or Chilton joke books.
I'm wondering if a new fuel pump can overheat system stays pressurized for a long time after engine is shut off
Is your new dist. the correct one for an '89 Corvette? Generic GM won't cut it! (No centrifugal weights and no vac advance.)
Last edited by Hot Rod Roy; Dec 4, 2015 at 12:17 AM.
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From: Mission Viejo CA
#1 TDC is still #1 TDC, and 6 deg. BTDC ignition timing would be set after the engine is running, so cam timing would not affect ignition setting. Cam advance would only affect the timing of the opening and closing of the valves.
Last edited by Hot Rod Roy; Dec 4, 2015 at 02:12 AM.
Thread Starter
Intermediate
Joined: Jul 2013
Posts: 36
Likes: 1
icm = Ignition Control Module (inside distributor)
fsm = Factory Service/ Shop Manual. Outstanding. Don't bother with Haynes or Chilton joke books.
It's excellent that fuel pressure is maintained! Pump can't overheat system. Since you're a mechanic, what is your theory on this question? Strange question in my opinion.
Is your new dist. the correct one for an '89 Corvette? Generic GM won't cut it! (No centrifugal weights and no vac advance.)
fsm = Factory Service/ Shop Manual. Outstanding. Don't bother with Haynes or Chilton joke books.
It's excellent that fuel pressure is maintained! Pump can't overheat system. Since you're a mechanic, what is your theory on this question? Strange question in my opinion.
Is your new dist. the correct one for an '89 Corvette? Generic GM won't cut it! (No centrifugal weights and no vac advance.)