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Re: 82 Corvette rough idle then dies out (4/14)
 6/10/21 7:12pm
benny65
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Joined: 8/16/2013
Posts: 11

It just started to happen, started it up last month and it ran fine, when I start it 2 weeks ago all this happen.  Where do I connect the pressure gauge to test fuel pressure?  Looking at the set up and can't figure it out.  Did a search, only see custom piping set up to test.  Any suggestion is appreciated.  Thanks.

Re: 82 Corvette rough idle then dies out (5/14)
 6/10/21 7:13pm
benny65
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Where do I connect the pressure gauge?  Thanks.

Re: 82 Corvette rough idle then dies out (6/14)
 6/10/21 8:58pm
73shark
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Overland Park, KS - USA

Vette(s):
1973 Orange Metallic Coupe (orig owner), L82, 4 spd (WR), PS, (A/C & PW (I installed from wrecked 73)), leather, AM/FM Stereo, ran with '65 FI unit earlier & will again some day.


Joined: 7/9/2003
Posts: 692

On my IROC, there was a Schrader fitting on the fuel rail.  Of course it was a TPI system whereby yours is dual TBI Cross-Fire setup.



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1973 L-82 4 spd

Re: 82 Corvette rough idle then dies out (7/14)
 6/11/21 6:13am
Adams' AppleLifetime Member
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Duncanville, TX - USA

Vette(s):
#1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas


Joined: 11/8/2003
Posts: 19854

Checking fuel pressure requires a "special tool" that replaces the fuel line that connects the 2 throttle bodies, allowing a gauge to be installed. Attached is the chart for checking the IAC system. 



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Re: 82 Corvette rough idle then dies out (8/14)
 6/20/21 2:14pm
benny65
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Joined: 8/16/2013
Posts: 11

Thanks for the reference page.  Reading the 1st block idle engine and record RPM in park or neutral, RPM is erratic surges from 400 RPM to 1500 RPM and dies out.  Don't know how to go farther if I can get pass this 1st step.  

I have so much to learn and figure out.  I guess I should find some way to test the pressure first before moving ahead.

Thanks for the help.

 

Here is a video link to show what the car is doing...

https://youtu.be/cgBwKQ3AMqk

Thanks for the help



|UPDATED|6/20/2021 11:14:03 AM (AZT)|/UPDATED|
Re: 82 Corvette rough idle then dies out (9/14)
 6/21/21 2:01pm
F4Gary
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Grapevine, TX - USA

Vette(s):
1972 LT-1 convertible with factory air.


Joined: 8/26/2006
Posts: 1069

The guys in this thread may have some helpful information.  There is also a link there to a TBI specialist site.

 

https://www.corvetteforum.com/forums/c3-general/4538608-my-crossfire-16146299-ecm-odyssey.html



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Re: 82 Corvette rough idle then dies out (10/14)
 6/27/21 4:54pm
benny65
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This is an update of my on going work in progress, I rebuilt the TBI with ACDelco OEM rebuilt kit, also install IAC OEM ACDelco part.  Car still idles rough and dies out.  But after restarting the car a few times, the car lose all power, when you turn key, no cranking, no sound.  I disconnect the battery and connect it back, it would start again.   But again after a few start up and die out, no power or cranking again.  Disconnect battery and start all over again.  Or let it sit for 5-10 minutes and it can be started again.  Is this leading to a bad ECM?

Still trying to figure out a way to check fuel pressure.  This is getting discouraging.

Any help or advice is highly appreciated.  Have an attachment of a video on post above to show how car runs and dies out.

 

Thanks






|UPDATED|6/27/2021 1:54:13 PM (AZT)|/UPDATED|
Re: 82 Corvette rough idle then dies out (11/14)
 6/27/21 5:05pm
73shark
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Overland Park, KS - USA

Vette(s):
1973 Orange Metallic Coupe (orig owner), L82, 4 spd (WR), PS, (A/C & PW (I installed from wrecked 73)), leather, AM/FM Stereo, ran with '65 FI unit earlier & will again some day.


Joined: 7/9/2003
Posts: 692

Try monitoring battery voltage during all of the start/restart cycles. Something seems strange. Probably the understatement of the day. 😉



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1973 L-82 4 spd

Re: 82 Corvette rough idle then dies out (12/14)
 6/28/21 1:09pm
F4Gary
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Grapevine, TX - USA

Vette(s):
1972 LT-1 convertible with factory air.


Joined: 8/26/2006
Posts: 1069

Was my link any help.  Those guys know a lot about the crossfire system.



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Re: 82 Corvette rough idle then dies out (13/14)
 6/28/21 1:57pm
benny65
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Joined: 8/16/2013
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F4Gary said:

Was my link any help.  Those guys know a lot about the crossfire system.

I check out the link, it was very informative about converting and changing over to a lot of aftermarket parts, but not much on troubleshooting and repairs.  Thanks for the info.  any help is appreciated.


Re: 82 Corvette rough idle then dies out (14/14)
 7/10/21 3:50pm
benny65
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Joined: 8/16/2013
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This is my update on my repair, finally acquired a fuel pressure gauge to check the pressure.  Pressure was next to none, like 3psi.  Took out the fuel pump, to my surprise the rubber hose that attach to the pump was crack.  I couldn't believe it, cause I change the whole unit about 5-6 years ago.  My original hose cracked at around 30 years, so this was the last thing I thought would be damage.  I replace the hose and ran the car, I got 9 psi and it was running fine.  I want to thank everyone here for their help and advice.  Much appreciated.  Thinking about putting in a 1985 fuel pump since I rebuilt the TBI already.

Going to enjoy the car this summer, I thought this summer was going to be a bust.  Thanks again for all the help.



|UPDATED|7/10/2021 12:50:20 PM (AZT)|/UPDATED|
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