82 corvette hard to start,won't idle cold & lousy mileage - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Engine> Modern Electronic Engines
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 02-19-2012, 08:25 PM
Registered User
 
Join Date: Feb 2012
Posts: 5
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
82 corvette hard to start,won't idle cold & lousy mileage

my 82 vette which use to get 25 mpg now gets about 9. i've replaced the temp sensor & upgraded to a jet chip. i subscribed to ask.com & attempted to check electronics per their instructions. other than the problems i mentioned , she performs normally. i live in the desert in se. nm. so the availability of talented local help is limited. i would consider going to carburetion if it would fit under my stock hood
Attached Thumbnails
Click image for larger version

Name:	217.JPG
Views:	89
Size:	380.8 KB
ID:	63130  

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 02-19-2012, 09:02 PM
Registered User
 
Last photo:
Join Date: Jul 2011
Location: Shawnee, Oklahoma
Posts: 78
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Well for the idle spraying a can of intake cleaner on the butterfly
where the mass air flow sensor is located helps. The carbon buildup
messes up the sensors readings and causes lots of problems.
Hold the butterfly open and spray away. You should be able to see where
the MAF sensor is so spray like half the bottle on it.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 02-20-2012, 10:13 AM
EagleMark's Avatar
GearHead-EFI.com
 
Join Date: Sep 2011
Location: North Idaho
Age: 54
Posts: 73
Wiki Edits: 0

Thanks: 0
Thanked 2 Times in 2 Posts
You can also ruin a MAF sensor by cleaning it improperly...

That is a very early and now very old EFI system. Before you start throwing parts at it I would get something to read engine data to see where the problem lies. Yes it could be MAF, or CTS sensor or a lot of other things like fuel pressure to high, blocked return line causing pressure to high or bad O2 sensor.

Do you have any CEL or error codes stored?

If you have a laptop, you can buy or make a cable and use TunerPro, free to try and only $39 to buy. All definitions are free. So once you get to using it on one car you can use it on others as well with out more costs per car!
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 03-09-2012, 07:15 PM
Registered User
 
Join Date: Feb 2012
Posts: 5
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
MAF sensor ???

I looked beneath the throttle blades & did not find anything that looked like a sensor. The parts clerk @ my local O'reillys looked up my 82 vette & said they do not have a MAF. Wassup!!!
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 03-09-2012, 07:19 PM
LATECH's Avatar
Hotrodders.com Moderator
 

Last journal entry: Motor - vator
Last photo:
Join Date: Jul 2010
Location: Northeast Pennsylvania
Posts: 5,299
Wiki Edits: 0

Thanks: 220
Thanked 272 Times in 252 Posts
So it is a crossfire injection system right?
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 03-09-2012, 07:39 PM
LATECH's Avatar
Hotrodders.com Moderator
 

Last journal entry: Motor - vator
Last photo:
Join Date: Jul 2010
Location: Northeast Pennsylvania
Posts: 5,299
Wiki Edits: 0

Thanks: 220
Thanked 272 Times in 252 Posts
put a scanner on it,look at the datastream and trouble codes (if any)
diagnose any trouble codes that arise. Then look at the data stream for anything that doesnt jive. Sounds like a CTS problem or possible MAP sensor, not to be confused with MAF sensor.
Also the ECM can substitute a value for a sensor that has an issue or fails, also it will use a value that was its last known good value if the corresponding circuit in the ECM fails as well.
My third guess would be a defective ECM...however dont just throw parts at it. Take a look at it and post back here what you have found.
Myself and/ or eagle mark are well versed in MEE as well as a handfull of others around here... and can help.
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 03-09-2012, 07:47 PM
Registered User
 
Join Date: Feb 2012
Posts: 5
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by latech
So it is a crossfire injection system right?
yes it an all original 82 vette which all had cease-fire injection
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 03-09-2012, 11:05 PM
EagleMark's Avatar
GearHead-EFI.com
 
Join Date: Sep 2011
Location: North Idaho
Age: 54
Posts: 73
Wiki Edits: 0

Thanks: 0
Thanked 2 Times in 2 Posts
Quote:
Originally Posted by evanst
yes it an all original 82 vette which all had cease-fire injection
I think your using a language translater?

Well if cease fire is same as cross fire it has 2 one barrel TBI units and would use a MAP sensor.
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 03-10-2012, 06:19 AM
LATECH's Avatar
Hotrodders.com Moderator
 

Last journal entry: Motor - vator
Last photo:
Join Date: Jul 2010
Location: Northeast Pennsylvania
Posts: 5,299
Wiki Edits: 0

Thanks: 220
Thanked 272 Times in 252 Posts
Hee hee... I see he has created a fond new "nickname" for his EFI.
When at the dealer, we commonly reffered to them as "campfire injection"
I understand the reason for GM going to this setup, but later setups like the Tuned port work much better.
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 03-12-2012, 06:36 PM
Registered User
 
Join Date: Feb 2012
Posts: 5
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
if my 82 has a MAP sensor, where is it located ? I see nothing below the throttle plates in the intake manifold [ plenum]
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 03-14-2012, 12:16 AM
Registered User
 
Join Date: Jul 2010
Location: hesperia
Posts: 27
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
i'm very familiar with your problem and the injection system on your car, do you have a hard time starting when cold? how does the engine respond when it's cold? does it run better cold or hot?

the most common problem with this system is a small hose inside the fuel tank, it goes between the pump and the feed line to the engine. the hose will rot out and get a small pin hole in it, it makes the car hard to start cold, respond bad and get horrible fuel mileage. pm me if you need more help. crossfire systems are very simple minded and it doesn't take much to make them run bad.
Reply With Quote Quick reply to this message
  #12 (permalink)  
Old 03-14-2012, 06:41 AM
T-bucket23's Avatar
Hotrodders.com Moderator
 
Last wiki edit: Engine basic condition - how to check Last photo:
Join Date: Aug 2005
Location: Massachusetts
Age: 57
Posts: 5,291
Wiki Edits: 26

Thanks: 7
Thanked 130 Times in 114 Posts
I have seen several of those with rotted vacuum lines as well. Before you go getting in to deep, check over all the vacuum lines for cracks or rot.
__________________
Artificial Intelligence is no match for Natural Stupidity



Chet
Reply With Quote Quick reply to this message
  #13 (permalink)  
Old 04-06-2012, 09:56 PM
Registered User
 
Join Date: Feb 2012
Posts: 5
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
good advice !!! after a year of sweating this problem , it was a broken vacuum connection @ the map sensor . thanks for the help!!!
Reply With Quote Quick reply to this message
  #14 (permalink)  
Old 04-07-2012, 11:43 AM
T-bucket23's Avatar
Hotrodders.com Moderator
 
Last wiki edit: Engine basic condition - how to check Last photo:
Join Date: Aug 2005
Location: Massachusetts
Age: 57
Posts: 5,291
Wiki Edits: 26

Thanks: 7
Thanked 130 Times in 114 Posts
Quote:
Originally Posted by evanst
good advice !!! after a year of sweating this problem , it was a broken vacuum connection @ the map sensor . thanks for the help!!!
Glad I/We could help. I am actually looking at an 82 myself right now. Similar issues and the guy just wants to dump it. I havent looked at it but he is so frustrated he might let it go for a grand. I will fix it and it may be my wifes summer car.


glad it worked out for you
__________________
Artificial Intelligence is no match for Natural Stupidity



Chet
Reply With Quote Quick reply to this message

Recent Modern Electronic Engines posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Carbed ls motor hard to start hot or cold sherman8r Engine 8 08-31-2012 04:17 PM
87 gm tbi hard to start when cold chevyAL Engine 4 01-14-2010 04:14 PM
Easy cold start, hard hot start dedub Engine 34 08-13-2008 05:21 PM
400 hard to start when cold zoc65 Engine 6 06-24-2008 07:56 AM
hard cold start akm Engine 19 05-16-2004 10:46 PM


All times are GMT -6. The time now is 09:33 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.