Sporatic Misfire
Thread Starter
4th Gear
Joined: Feb 2018
Posts: 4
Likes: 0
Sporatic Misfire
My '93 manual Corvette will randomly misfire for about five seconds while driving with no apparent pattern. The fuel pump has replaced. During the event the tach. will bounce around erratically with no check engine light. The car always starts fine and there are no residual symptoms.
C4 Blues.
C4 Blues.
Race Director
Joined: Oct 2008
Posts: 17,982
Likes: 1,072
From: Lansing MI
The erratic tach while its acting up is a pretty big indication the distributor is done. I would stop driving the car if you haven't already.
In the event you are planning on changing it yourself, then start by hosing the center of the harmonic balancer with penetrating oil. Do that today.
Thread Starter
4th Gear
Joined: Feb 2018
Posts: 4
Likes: 0
Done. I now have Blaster break free all over the front of my motor. So I'm thinking, the teardown requires removal of the water pump and harmonic balancer AND throttle body, that this would be a good time to change the front engine seal. Does that require removal of the steering rack? Speaking of throttle body, is there a good reason a previous owner would bypass the coolant line into the unit?
Race Director
Joined: Oct 2008
Posts: 17,982
Likes: 1,072
From: Lansing MI
Done. I now have Blaster break free all over the front of my motor. So I'm thinking, the teardown requires removal of the water pump and harmonic balancer AND throttle body, that this would be a good time to change the front engine seal. Does that require removal of the steering rack? Speaking of throttle body, is there a good reason a previous owner would bypass the coolant line into the unit?
As far as bypassing the throttle body coolant lines, some people think it helps power by keeping the intake air cooler than it would otherwise be. Some people also think the earth is flat. Personally, I don't believe either one of those things.
Cruising
Joined: Jun 2017
Posts: 11
Likes: 0
Done. I now have Blaster break free all over the front of my motor. So I'm thinking, the teardown requires removal of the water pump and harmonic balancer AND throttle body, that this would be a good time to change the front engine seal. Does that require removal of the steering rack? Speaking of throttle body, is there a good reason a previous owner would bypass the coolant line into the unit?
power at all of course, just a no brainier for me to do since I was there anyway and it certainly won't hurt anything to do it. Can't help on the other questions because I haven't had to do my Opti yet(knock on wood).
Mark.
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