1984 Engine Questions
Thread Starter
Cruising
Joined: Sep 2016
Posts: 12
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1984 Engine Questions
Hi guys. I am looking for some advice, I went to check out a 1984 Corvette today and I had two specific questions. I drove the car for a few minutes and the transmission was smooth but once it was parked and we lifted the hood I noticed a knocking that got slightly louder as it stayed idle. One of the guys said that it's normal because that's the noise of the cross fire fuel injection. I am wondering if that is true or just some bs that was said.
The other question is that when I took the oil cap off there was no resistance, usually when you take an oil cap off when the car is running you have some suction which would hold the cap in place. On this car it came right off. Just looking for some in site into these concerns.
Thanks,
Josh
The other question is that when I took the oil cap off there was no resistance, usually when you take an oil cap off when the car is running you have some suction which would hold the cap in place. On this car it came right off. Just looking for some in site into these concerns.
Thanks,
Josh
Drifting
Joined: Feb 2013
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Safety Car
Joined: Sep 2004
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From: Mission Viejo CA
For the bs/truth test, remove the air filter cover, then touch the tip of a long screwdriver to the injectors, and the end of the handle against your ear. Is that the noise the seller is calling "normal"?
I haven't noticed any "knocking" noise from my CrossFire injectors.
I haven't noticed any "knocking" noise from my CrossFire injectors.
Race Director
Joined: Oct 2005
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From: Rolla Missouri
2021 C4 of the Year - Unmodified Finalist
St. Jude Donor '10 thru '25
The OP needs to better describe what he means by "knocking".
Knocking sure wouldn't be normal.
But as ex-x-fire mentioned, those throttle body injectors can "tick" quite loudly, and if your not used to hearing them might think something is wrong.
Knocking sure wouldn't be normal.
But as ex-x-fire mentioned, those throttle body injectors can "tick" quite loudly, and if your not used to hearing them might think something is wrong.
Race Director
Joined: Oct 2005
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From: Rolla Missouri
2021 C4 of the Year - Unmodified Finalist
St. Jude Donor '10 thru '25
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From: Mission Viejo CA
Safety Car
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From: Arizona - If you don’t know CFI, STOP proliferating the myths around it...
Do you even know what a CFI motor looks like? It has two TBs and two injectors if it is stock. Also, the injectors do make a ticking sound as they fire...knocking no, but they do make a ticking noise. Yet another post for CFI mis-information.
Last edited by Buccaneer; Sep 17, 2016 at 01:33 AM.
Melting Slicks
Joined: Oct 2015
Posts: 2,644
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From: Connecticut
The transmission in my 84 is VERY clunky, putting it in drive and reverse really shift the car almost making it jerk and rattles the whole car, driving it completely fine, mine has a carb on it so not sure about the crossfire...
Last edited by BrandensBeast; Sep 17, 2016 at 11:42 AM.
Advanced
Joined: Sep 2016
Posts: 57
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I do think we need more word on if this is actual engine knock or just one of the ticks coming from several sources, mainly those injectors.
For the OP, can you check the exhaust? Do you smell rotten eggs faintly? Are the bolts to the cat rusted or slightly so, indicating it is original? A clogged old cat could be causing back pressure and causing a few issues. Try going up a hill and seeing if it struggles more than it should.
For the OP, can you check the exhaust? Do you smell rotten eggs faintly? Are the bolts to the cat rusted or slightly so, indicating it is original? A clogged old cat could be causing back pressure and causing a few issues. Try going up a hill and seeing if it struggles more than it should.
Racer
Joined: Mar 2009
Posts: 251
Likes: 1
From: Windsor Connecticut
In previous posts, you have said that you bought your '84 in 1983. As a very long term owner, this is a surprising comment! I'm sure you have heard of CFI? You must know what that stands for! Is your car in a museum someplace? Have you ever taken off your air filter cover? It's a real education under those two black *****! What are we missing here?