Fuel or computer problem
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 32
From: The Top of Utah
From my April 1989 Corvette Parts Book.
Calibrator (Prom):
1984 W/A.T. Prom, Code: 3235CCC, 3940CDR..................PN 1226466
1984 W/M.T. Calif. Code: 3879CDF, 9842DBP...................PN 1225428
1984 W/M.T. FED. Code: 3661CDK, 3846DBR....................PN 1225429
1984 W/NM5 (Export, Canada) Code: 4044CFB, 8577CFB....PN 1226842
Controller (ECM)
1984 W/A.T. Fed, Calif................PN 1226026 (Reman.)
1984 W/M.T. (MK2)....................PN 1226430 (Reman.)
1984 W/NM5 (Export, Canada)......PN 1226430 (Reman.)
RACE ON!!!
Calibrator (Prom):
1984 W/A.T. Prom, Code: 3235CCC, 3940CDR..................PN 1226466
1984 W/M.T. Calif. Code: 3879CDF, 9842DBP...................PN 1225428
1984 W/M.T. FED. Code: 3661CDK, 3846DBR....................PN 1225429
1984 W/NM5 (Export, Canada) Code: 4044CFB, 8577CFB....PN 1226842
Controller (ECM)
1984 W/A.T. Fed, Calif................PN 1226026 (Reman.)
1984 W/M.T. (MK2)....................PN 1226430 (Reman.)
1984 W/NM5 (Export, Canada)......PN 1226430 (Reman.)
RACE ON!!!
Drifting
Joined: May 1999
Posts: 1,478
Likes: 3
From: Sacramento, CA Money can't buy happiness - but it's more comfortable to cry in a Corvette than a Yugo.
Originally Posted by 7thvet
A reconditioned ECC is $70, from Napa. $100 from chevy.
The prom from chevy is $60.Napa couldnt get that perticular one.
A O2 sensor from chevy is $60, & $35 from Napa.
I want to try my prom in the Napa.
I dont want to wait for chevy to get that prom.
Money isnt that tight , but I know you guys dont want me to spend it.Thats why I didnt opt for next day air.
Thanks for your concern.
Thanks everyone.
We'll all know tommorrow at about 5pm.
The prom from chevy is $60.Napa couldnt get that perticular one.
A O2 sensor from chevy is $60, & $35 from Napa.
I want to try my prom in the Napa.
I dont want to wait for chevy to get that prom.
Money isnt that tight , but I know you guys dont want me to spend it.Thats why I didnt opt for next day air.
Thanks for your concern.
Thanks everyone.
We'll all know tommorrow at about 5pm.
Thread Starter
Melting Slicks
Joined: May 2005
Posts: 3,134
Likes: 11
From: At the St. Louis Playboy club.
Hi thanks.
The prom chevy wants to sell me is #1226466.
The Prom in my ECC is the first one listed by CFI-EFI #3940CDR.
It looks like they are the same, just I dont have the part # of mine just that CDR #.
What does that tell me?
I'll check in at lunch time to see what you say before I try it.
The part # for the ECM is 88999109
Thanks
The prom chevy wants to sell me is #1226466.
The Prom in my ECC is the first one listed by CFI-EFI #3940CDR.
It looks like they are the same, just I dont have the part # of mine just that CDR #.
What does that tell me?
I'll check in at lunch time to see what you say before I try it.
The part # for the ECM is 88999109
Thanks
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 32
From: The Top of Utah
The two codes listed are what a 1984 automatic SHOULD have. The 1226466 is the PART number for the chip with either code.
"1984 W/A.T. Prom, Code: 3235CCC, 3940CDR..................PN 1226466"
Tells you that the part number to order to replace a prom with "that CDR #" (3940CDR) is 1226466. It also confirms, that IF you have a 1984 corvette, with an automatic transmission, not built with the "Export to Canada" RPO of NM5, that the prom already in your car is the correct prom.
RACE ON!!!
"1984 W/A.T. Prom, Code: 3235CCC, 3940CDR..................PN 1226466"
Tells you that the part number to order to replace a prom with "that CDR #" (3940CDR) is 1226466. It also confirms, that IF you have a 1984 corvette, with an automatic transmission, not built with the "Export to Canada" RPO of NM5, that the prom already in your car is the correct prom.
RACE ON!!!
Drifting
Joined: May 1999
Posts: 1,478
Likes: 3
From: Sacramento, CA Money can't buy happiness - but it's more comfortable to cry in a Corvette than a Yugo.
Originally Posted by CFI-EFI
Controller (ECM)
1984 W/A.T. Fed, Calif................PN 1226026 (Reman.)
1984 W/M.T. (MK2)....................PN 1226430 (Reman.)
1984 W/NM5 (Export, Canada)......PN 1226430 (Reman.)
1984 W/A.T. Fed, Calif................PN 1226026 (Reman.)
1984 W/M.T. (MK2)....................PN 1226430 (Reman.)
1984 W/NM5 (Export, Canada)......PN 1226430 (Reman.)
According to their online site the two NAPA ECM part numbers for the 84 are:
GM #1226026 - NAPA # NEC XTP613
GM #1226430 - NAPA # NEC XTP139
For those who are interested, 85-91 GM ECM part numbers where transmisson type does not matter:
GM #1226870 - 85 auto/manual
GM #1227165 - 86-89 auto/manual
GM #1227727 - 90-91 auto/manual (L-98)
Thread Starter
Melting Slicks
Joined: May 2005
Posts: 3,134
Likes: 11
From: At the St. Louis Playboy club.
Well guys the new computer worked.
I knew immeadatly when I started it. I was looking at the injectors.
I saw they were spraying cone shape but with alot less volume than before.
I could "see" the differerence.
It ran smoother.
Also, no codes
The average gas miliage tripled.
I was so excited I drove right to the emmissions testing place.
But it barely failed.
But it improved a hundred fold.
It failed HC it read 2.0899.Ive got to get that down to 0.8
The Co & No passed. They were real bad last time I tested.
What do I need to do to lower HC?
Should I have driven it for a while to clean out the cat?
Thanks all you guys.
I knew immeadatly when I started it. I was looking at the injectors.
I saw they were spraying cone shape but with alot less volume than before.
I could "see" the differerence.
It ran smoother.
Also, no codes
The average gas miliage tripled.
I was so excited I drove right to the emmissions testing place.
But it barely failed.
But it improved a hundred fold.
It failed HC it read 2.0899.Ive got to get that down to 0.8
The Co & No passed. They were real bad last time I tested.
What do I need to do to lower HC?
Should I have driven it for a while to clean out the cat?
Thanks all you guys.
Le Mans Master
Joined: Oct 2003
Posts: 6,130
Likes: 2
From: seattle WA
that's cool.How long did you drive it before the test? Have you changed the oil lately and checked the air cleaner.You may need to drive it more- sometimes the computer has to
learn from your driving and make adjustments. I'm very happy for you.
Last edited by rick lambert; Mar 30, 2006 at 05:25 PM.
Drifting
Joined: May 1999
Posts: 1,478
Likes: 3
From: Sacramento, CA Money can't buy happiness - but it's more comfortable to cry in a Corvette than a Yugo.
Originally Posted by 7thvet
Well guys the new computer worked.
I knew immeadatly when I started it. I was looking at the injectors.
I saw they were spraying cone shape but with alot less volume than before.
I could "see" the differerence.
It ran smoother.
Also, no codes
The average gas miliage tripled.
I was so excited I drove right to the emmissions testing place.
But it barely failed.
But it improved a hundred fold.
It failed HC it read 2.0899.Ive got to get that down to 0.8
The Co & No passed. They were real bad last time I tested.
What do I need to do to lower HC?
Should I have driven it for a while to clean out the cat?
Thanks all you guys.
I knew immeadatly when I started it. I was looking at the injectors.
I saw they were spraying cone shape but with alot less volume than before.
I could "see" the differerence.
It ran smoother.
Also, no codes
The average gas miliage tripled.
I was so excited I drove right to the emmissions testing place.
But it barely failed.
But it improved a hundred fold.
It failed HC it read 2.0899.Ive got to get that down to 0.8
The Co & No passed. They were real bad last time I tested.
What do I need to do to lower HC?
Should I have driven it for a while to clean out the cat?
Thanks all you guys.
rick lambert lists very good points about pre-emmissions things to do. Before I get mine emmissions tested, I always put in a new Purolator air filter, change to fresh oil, new cap & rotor, pull & check the gap of the plugs. Then drive it enough for the ECM to "learn" about the changes and make sure it is really well warmed up before going to the test station.
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Thread Starter
Melting Slicks
Joined: May 2005
Posts: 3,134
Likes: 11
From: At the St. Louis Playboy club.
She was warm.
It was kicking on the fan at about 220, while I was waiting in line.
The emmissons place is only about 3 miles away.
So I should of driven it for a while.
I was just so happy I thought It would pass & I'd be able to report a complete sucsess.
The mileage improvement will pay for the parts.
I changed the oil a couple of weeks ago ,but that doesnt mean its not contaminated.
You know what I dont have & think I need is the little filter that goes in the air cleaner. Its like a breather filter?
Plus I have a K&N air filter, its clean.
Thank you guys so much. This really the first time since 1999 that this car has run right, almost right.
I dont know why I kept avoiding the computer, throwing sensors needlessly at it.
I live & learn.
Thanks again you guys.
Do you think I just need to drive it?
It could use some fresh gas.
I may get to drive it this weekend 120 mile round trip.
It was kicking on the fan at about 220, while I was waiting in line.
The emmissons place is only about 3 miles away.
So I should of driven it for a while.
I was just so happy I thought It would pass & I'd be able to report a complete sucsess.
The mileage improvement will pay for the parts.
I changed the oil a couple of weeks ago ,but that doesnt mean its not contaminated.
You know what I dont have & think I need is the little filter that goes in the air cleaner. Its like a breather filter?
Plus I have a K&N air filter, its clean.
Thank you guys so much. This really the first time since 1999 that this car has run right, almost right.
I dont know why I kept avoiding the computer, throwing sensors needlessly at it.
I live & learn.
Thanks again you guys.
Do you think I just need to drive it?
It could use some fresh gas.
I may get to drive it this weekend 120 mile round trip.
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 32
From: The Top of Utah
HCs (Hydro Carbons) are unburned fuel. They CAN result from the unburned portion of a rich mixture, they can be the result of a misfire, even one you may not detect, and they can be introduced via the PCV system. With all the piddling you've done on your car lately, you could probably drain your oil pan into your gas tank and have it run.
Do everything rick lambert said, then take it out and drive the **** out of it. Take it for a good loooong drive. Let it get, and stay, hot for a while. Then after it cools, check the plugs one more time, make sure the cap and rotor are up to snuff and then get it good and warm (hot) before the next shot at the smog test. If you still have a cat, it ought to be duck soup.
RACE ON!!!
Do everything rick lambert said, then take it out and drive the **** out of it. Take it for a good loooong drive. Let it get, and stay, hot for a while. Then after it cools, check the plugs one more time, make sure the cap and rotor are up to snuff and then get it good and warm (hot) before the next shot at the smog test. If you still have a cat, it ought to be duck soup.
RACE ON!!!
Thread Starter
Melting Slicks
Joined: May 2005
Posts: 3,134
Likes: 11
From: At the St. Louis Playboy club.
Originally Posted by CFI-EFI
HCs (Hydro Carbons) are unburned fuel. They CAN result from the unburned portion of a rich mixture, they can be the result of a misfire, even one you may not detect, and they can be introduced via the PCV system. With all the piddling you've done on your car lately, you could probably drain your oil pan into your gas tank and have it run.
Do everything rick lambert said, then take it out and drive the **** out of it. Take it for a good loooong drive. Let it get, and stay, hot for a while. Then after it cools, check the plugs one more time, make sure the cap and rotor are up to snuff and then get it good and warm (hot) before the next shot at the smog test. If you still have a cat, it ought to be duck soup.
RACE ON!!!
Do everything rick lambert said, then take it out and drive the **** out of it. Take it for a good loooong drive. Let it get, and stay, hot for a while. Then after it cools, check the plugs one more time, make sure the cap and rotor are up to snuff and then get it good and warm (hot) before the next shot at the smog test. If you still have a cat, it ought to be duck soup.
RACE ON!!!
Thanks for your help also, & all the guys.
You think my cats crap?
Does the cat affect HCs?
I bet my cylinders valves exhaust everything has carbon build up.
I think a drive will help.
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 32
From: The Top of Utah
I'm not saying I think your cat is crap. I was just asking if you have one. It isn't easy. but mine passes without a cat. If you have one, you really should be able to get it to pass fairly easily.
RACE ON!!!
RACE ON!!!
Thread Starter
Melting Slicks
Joined: May 2005
Posts: 3,134
Likes: 11
From: At the St. Louis Playboy club.
Yes I have a cat its about 2 years old.
Thats what I think made it pass emmissions 2 years ago.
We were talking about this earlier, did it clogg up from all the fuel its been dumping into it.
I want to thank you for saving me $60 on a prom.Thanks for those part #s, & all your input.
Thats what I think made it pass emmissions 2 years ago.
We were talking about this earlier, did it clogg up from all the fuel its been dumping into it.
I want to thank you for saving me $60 on a prom.Thanks for those part #s, & all your input.
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 32
From: The Top of Utah
I'm all about not wasting money. I'm happy I could help. You may have hurt the cat as much as you ran it rich. I'd start with all the recommendations and see if it passes. I'm thinking it will pass. Based on what kind of numbers it generates, we can help you test the cat and prepare for a follow up test, if necessary.
RACE ON!!!
RACE ON!!!
and well done guys
Le Mans Master
Joined: Oct 2003
Posts: 6,130
Likes: 2
From: seattle WA
Don't know when your next test is-and here I go 
I'd get a can of SeaFoam, about $5. when I use it I don't follow their directions-instead
I put one half can in fuel tank, one half through vacumn-I use the brake booster. IF you do it-TWO, maybe three things, keep the RPMs up around 1800 while putting it through the vac line-it's gonna smoke like hell for ma few minutes-AND you may throw an 02 code-I said MAY, if you do don't worry, it burns off, then just disconnect the battry for a few minutes to clear the code.Quote from the can "helps pass emmisions". MAIN thing is get that oil changed-probably fuel contaminated.
Then take it out and run it-make sure you get it up to operating temps-let it cool down and do it again.
I'd get a can of SeaFoam, about $5. when I use it I don't follow their directions-insteadI put one half can in fuel tank, one half through vacumn-I use the brake booster. IF you do it-TWO, maybe three things, keep the RPMs up around 1800 while putting it through the vac line-it's gonna smoke like hell for ma few minutes-AND you may throw an 02 code-I said MAY, if you do don't worry, it burns off, then just disconnect the battry for a few minutes to clear the code.Quote from the can "helps pass emmisions". MAIN thing is get that oil changed-probably fuel contaminated.
Then take it out and run it-make sure you get it up to operating temps-let it cool down and do it again.
Last edited by rick lambert; Mar 31, 2006 at 12:21 PM.
