Automotive Forums .com - the leading automotive community online! Automotive Forums .com - the leading automotive community online!
Automotive Forums .com - the leading automotive community online! 
-
Latest | 0 Rplys
Go Back   Automotive Forums .com Car Chat > Chevrolet > Corvette
Corvette
Reply Show Printable Version Show Printable Version | Email this Page Email this Page | Subscription Subscribe to this Thread
 
Thread Tools Search this Thread
Old 05-25-2013, 01:33 PM   #1
JGMJ
AF Newbie
 
Join Date: May 2013
Location: Burleson, Texas
Posts: 6
Thanks: 3
Thanked 0 Times in 0 Posts
1985 Corvette starting and interior lights problems.

My 85 Corvette has been stored since 1995. It has travelled less than 17,000 miles and was working perfectly when stored. When the battery is connected, the fuel pump is activated and the door lights come on sporadically, draining the battery (The ignition switch remains in the off position and the doors are closed.) I have replaced the pump and sending unit and this new pump also starts when the battery is connected (but with the ignition in the off position). I have also changed the fuel filter. The engine turns over quickly but does not start. I poured some gas on to the air filter and the engine immediately fired up and runs until the gas in the air filter has been used up. I've also tried a new Fuel pump relay, with no effect.
Questions: 1) Why does the pump start running when the Ignition is off and the battery is connected?. 2) What is stopping the gas from reaching the engine? and 3) Another topic. Why do the door courtesy lights come on when the Ignition is off and the doors closed?
JGMJ is offline   Reply With Quote
Old 05-26-2013, 10:07 PM   #2
Schrade
AF Enthusiast
 
Join Date: May 2005
Location: Snow Hill, North Carolina
Posts: 690
Thanks: 0
Thanked 1 Time in 1 Post
Re: 1985 Corvette starting and interior lights problems.

Is the motor OEM configuration? L98?
Schrade is offline   Reply With Quote
The Following User Says Thank You to Schrade For This Useful Post:
JGMJ (05-27-2013)
Old 05-27-2013, 08:19 AM   #3
autojoe
AF Regular
 
Join Date: Jan 2004
Location: Newbrighton, Pennsylvania
Posts: 193
Thanks: 1
Thanked 12 Times in 12 Posts
Re: 1985 Corvette starting and interior lights problems.

gm used a oil pressure switch as a backup for a failed fuel pump relay.contacts would close about 4 psi oil pressure and provide voltage to pump.may take a few seconds before starting.I dont know what year they started that....maybe 1986.if you have that then switch maybe shorted.try disconnecting the oil pressure switch.The lights would be controlled by a body control module I think.I am not at work.I would have to look up on my alldata.Carb spray is safest to spray into throttle body to test for fuel problems.apparently your injectors are not being pulsed......computer has to see a crank signal before grounding injectors.did the drain and lighting issue and no start and pump running all the time happen together?let me know engine size.
autojoe is offline   Reply With Quote
The Following User Says Thank You to autojoe For This Useful Post:
JGMJ (05-27-2013)
Old 05-27-2013, 12:52 PM   #4
Blue Bowtie
Registered Offender
 
Blue Bowtie's Avatar
 
Join Date: Mar 2006
Location: Rural
Posts: 6,037
Thanks: 3
Thanked 256 Times in 252 Posts
Re: 1985 Corvette starting and interior lights problems.

A-Joe,

In this case, size doesn't matter. It's a TPI, and the '85 version of the Bosch/Delco TPI with the 16K EPROM, analog MAF, cold start injector, and all the baggage that went along with it.

Good call on the auxiliary oil pressure switch!

Obviously, the distributor is generating reference pulses since the engine runs if fuel is applied. Check the INJ1 and INJ2 fuses to verify the injectors have supply voltage. Verify proper fuel rail pressure with a gauge - Minimum 34 PSIG KOEO.

As for the interior lights, check the door and deck switches and their wiring first, and the IP light dimmer since it has a courtesy lamp override at its full-on position. If those are intact, check the courtesy lamp theater lighting module. I've had a few of them fail with the transistor in the shorted E-C mode which keeps the light on constantly. P/N 14080625. It's behind the RH kick panel.
__________________
Permanent seat assignment on the Group W bench...
Automotive Forums Survival Guide
Blue Bowtie is offline   Reply With Quote
The Following User Says Thank You to Blue Bowtie For This Useful Post:
JGMJ (05-27-2013)
Old 05-27-2013, 01:14 PM   #5
JGMJ
AF Newbie
Thread starter
 
Join Date: May 2013
Location: Burleson, Texas
Posts: 6
Thanks: 3
Thanked 0 Times in 0 Posts
Re: 1985 Corvette starting and interior lights problems.

Yes , it is a L98
JGMJ is offline   Reply With Quote
Old 05-27-2013, 01:16 PM   #6
JGMJ
AF Newbie
Thread starter
 
Join Date: May 2013
Location: Burleson, Texas
Posts: 6
Thanks: 3
Thanked 0 Times in 0 Posts
Re: 1985 Corvette starting and interior lights problems.

Thanks for taking the trouble to answer. I'll start to apply your ideas.
JGMJ is offline   Reply With Quote
Old 05-27-2013, 01:28 PM   #7
JGMJ
AF Newbie
Thread starter
 
Join Date: May 2013
Location: Burleson, Texas
Posts: 6
Thanks: 3
Thanked 0 Times in 0 Posts
Re: 1985 Corvette starting and interior lights problems.

Blue Bowtie.
Thanks for all the information. I'll start applying your recommendations.
JGMJ is offline   Reply With Quote
Old 05-27-2013, 01:45 PM   #8
JGMJ
AF Newbie
Thread starter
 
Join Date: May 2013
Location: Burleson, Texas
Posts: 6
Thanks: 3
Thanked 0 Times in 0 Posts
Re: 1985 Corvette starting and interior lights problems.

Autojoe. The Engine is the 5.7 litre L-98. All problems occurred simultaneously when I started the process of getting the car running. (added a new battery)
JGMJ is offline   Reply With Quote
Old 05-27-2013, 10:53 PM   #9
autojoe
AF Regular
 
Join Date: Jan 2004
Location: Newbrighton, Pennsylvania
Posts: 193
Thanks: 1
Thanked 12 Times in 12 Posts
Re: 1985 Corvette starting and interior lights problems.

oil pressure switch has an orange wire and a red wire.with key in on position there should be no voltage on red wire.....or disconnect with key in on position and see if pump quits running.....if there is voltage on red wire and pump quits running when oil pressure switch is disconnected then replace the switch.see if injector 1 and injector 2 fuses are good.if they are good then you will have to see if the drivers inside the computer are working.these are bank fired injectors and you have 2 banks of 4 injectors.take a test light connected to ground....i always use the negative battery terminal....injectors 1,3,5,7 the control wires will be light blue....backprobe this wire at one of the injectors 1,3,5,7 and observe test light during cranking....the test light should flicker.next on injectors 2,4,6,8 the control wire color is light green...back probe one of these injectors and see if test light flickers.this will tell you if computer is pulsing the injectors on and off.How is the fuel quality in tank?alcohol/moisture?
autojoe is offline   Reply With Quote
Old 05-31-2013, 03:49 PM   #10
JGMJ
AF Newbie
Thread starter
 
Join Date: May 2013
Location: Burleson, Texas
Posts: 6
Thanks: 3
Thanked 0 Times in 0 Posts
Re: 1985 Corvette starting and interior lights problems.

Autojoe and Blue Bowtie: Thank you for your advice, which I am now trying to implement. My local mechanic printed out the location of the Oil Pressure sender.(Alldata.) It is shown at the rear of the Engine next to the Distributor (Driver's side). I haven't been able to locate it there. (I'm assuming that the Oil Pressure Switch and Oil Pressure Sender are the same.) Where should I find the Oil Pressure Switch?
JGMJ is offline   Reply With Quote
Old 05-31-2013, 08:47 PM   #11
autojoe
AF Regular
 
Join Date: Jan 2004
Location: Newbrighton, Pennsylvania
Posts: 193
Thanks: 1
Thanked 12 Times in 12 Posts
Re: 1985 Corvette starting and interior lights problems.

autojoe is offline   Reply With Quote
 
Reply

POST REPLY TO THIS THREAD


Bookmarks
Go Back   Automotive Forums .com Car Chat > Chevrolet > Corvette

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not 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



All times are GMT -5. The time now is 07:57 PM.

Community Participation Guidelines | How to use your User Control Panel

Powered by: vBulletin | Copyright Jelsoft Enterprises Ltd.
 
 
no new posts