C4 Tech/Performance L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

1985 won't start

Old Feb 19, 2010 | 11:53 PM
  #1  
zeek racing's Avatar
zeek racing
Thread Starter
Heel & Toe
 
Joined: Mar 2002
Posts: 24
Likes: 0
From: Benton Ar
Default 1985 won't start

I'm working on a 85 vette with tuned port. Someone had changed the intake with one off of a firebird, injectors and all. The guy could not ever get it running right after that. I discovered it had the wrong injectors on it, too small. I ordered some new injectors off of a web site. They called for 22lbs injectors. I have noticed on here that 85 had 24lbs and 22lbs on 86 and later. I know if the injectors are a little small it should still start just not run right. After the injector swap I checked for leaks and was good there. I tried starting the car and it would just turn over and not fire up. I check fuel pressure and it was at 40. Then I pulled the plugs and they were fauled and covered in gas. I grabbed a plug that I had laying around to check for spark, we had spark. I ran to the parts store and got another set, put them in and nothing. The car just continues to turn over. The car ran before I worked on it, but very badly. His digital guages are not coming on also. They normally go on and off while driving. I don't understand why this thing is not running. Please help, thanks! I replaced the injectors with the bosh III style.

Last edited by zeek racing; Feb 20, 2010 at 12:00 AM. Reason: style of injector
Reply
Old Feb 20, 2010 | 12:22 AM
  #2  
jfb's Avatar
jfb
Team Owner
20 Year Member
 
Joined: Mar 2001
Posts: 54,124
Likes: 30
From: Cincinnati, Oh USA
Default

Wet plugs is a sign of leaking injectors flooding the engine. Too rich condition will never start! Engines need spark and spark at the right time, fuel and air and in the correct ratio and compression in order to start and run. Use a timing light to see if you have spark at the right time during cranking. Use a noid light (available at parts store) or make one with an LED and a series 680 ohm resistor (polarity must be correct on the injector plug) and see if you have injector pulses during cranking. Watch the fuel pressure after the ign is turned off, it should hold up for a long time. If it drops rapidly you may have leaky injectors or a defective check valve in the fuel pressure regulator. I'd even check compression. Also, pull any stored codes. Unplug the MAF and see if it will start, you may also have a defective MAF.
And from you post in the general section, car batteries left sitting for a long time and not kept charged up are door stops. Trying to start a car with a totally dead battery and jumper cables isn't always successful because of the high voltage drop across the jumper cables. C4's won't run below about 10 volts. Put a good battery in place of your dead one. From now on, use a battery tender (trade name) on your battery when you aren't going to use the car for over a month. If you keep your battery charged you will experience normal battery life, letting it sit ruins the battery, even disconnected!

Last edited by jfb; Feb 20, 2010 at 12:47 AM.
Reply
Old Feb 20, 2010 | 12:45 AM
  #3  
Frizlefrak's Avatar
Frizlefrak
Race Director
20 Year Member
 
Joined: Dec 2000
Posts: 17,551
Likes: 26
From: El Paso Texas
Default

Also, check for a large vacuum leak. Introducing "false air" into the engine tricks the ECM into thinking it's too lean, and it richens the mixture to compensate.

Let's expand on the leaking injector thing for a moment. Get a helper to assist....hook up your fuel pressure gauge. Pinch off the return line with vice grips as close to the rail as possible. Now, have your assistant turn the key on but don't crank the engine. Immediately after the 2 second prime, pinch off the pressure line as well. Now watch your gauge. With both fuel lines pinched off tightly, it should hold 40 or so psi indefinitely. If the pressure suddenly falls off, you have a leaking injector(s). If not, you don't.

Now....they may not be pulsing correctly and may be hung open when grounded. Or you may have a bad injector driver in the ECM, but we will cross that bridge if/when we get to it.

Run the test, post the results
Reply
Old Feb 20, 2010 | 05:17 PM
  #4  
klkordzi's Avatar
klkordzi
Instructor
10 Year Member
 
Joined: Nov 2005
Posts: 161
Likes: 0
From: Pittsburgh Penna.
Default

As was already suggested, check the voltage. I would also check to make sure the the distributer was set right when the previous owner put it back in. Also at the back of the manifold is ground that would have had to be removed when the manifold was replaced. I'd check that also.
Reply
Old Feb 20, 2010 | 05:31 PM
  #5  
pletzvet's Avatar
pletzvet
Pro
10 Year Member
 
Joined: Nov 2005
Posts: 602
Likes: 0
From: North Bay Ontario
Default

Originally Posted by zeek racing
Someone had changed the intake with one off of a firebird, injectors and all. The guy could not ever get it running right after that.
Running right? or Running period? I'd be suspecting the problem is related to the intake change. Apart from wondering why the intake was changed, I'd be checking that the distributor has be re-installed properly. Have you checked the timing or at least checked that it is close even without the engine running?
Reply
Old Feb 21, 2010 | 07:06 PM
  #6  
zeek racing's Avatar
zeek racing
Thread Starter
Heel & Toe
 
Joined: Mar 2002
Posts: 24
Likes: 0
From: Benton Ar
Default

I took apart the dist cap and one of the connectors was off of the control module. I pluged it back up and fixed some rigged up wiring and vooom, it started. There are some hesitation when you first floor it. I'm going to check the timing and the tps sensor and maybe I can take care of that, but its running great. thanks everyone!
Reply
Old Feb 21, 2010 | 07:57 PM
  #7  
Harsh20's Avatar
Harsh20
Instructor
 
Joined: Nov 2008
Posts: 199
Likes: 1
From: Asheboro NC
Default

i was going to say the timing was off but you got it. good luck with it
Reply

Get notified of new replies

To 1985 won't start



Thread Tools
Search this Thread

All times are GMT -4. The time now is 07:03 PM.

story-0
2027 Chevrolet Silverado 1500 First Look: Everything You NEED to Know!

Slideshow: Is the 2027 Chevrolet Silverado 1500 the best Silverado yet?

By Michael S. Palmer | 2026-06-16 08:01:12


VIEW MORE
story-1
5 Best & 5 Worst Corvette Daily Drivers

Slideshow: 5 best and 5 worst Corvette daily drivers

By Joe Kucinski | 2026-06-15 10:32:13


VIEW MORE
story-2
The Headlights of Every Corvette Generation Explained

Slideshow: The headlights of every Corvette generation explained

By Joe Kucinski | 2026-06-15 10:17:14


VIEW MORE
story-3
5 Best & 5 Most Overrated Corvette Track Packages of All Time!

Slideshow: The 5 best and 5 most overrated Corvette track packages ever.

By Joe Kucinski | 2026-06-09 12:46:45


VIEW MORE
story-4
Every 2027 Corvette Engine Explained

Slideshow: Every 2027 Corvette engine explained

By Joe Kucinski | 2026-06-09 12:16:31


VIEW MORE
story-5
Designer Imagines A Corvette That Looks More Like a Corvette Than the Corvette

Slideshow: A Jaguar designer's personal project imagines what a modern front-engined Corvette might look like if Chevrolet revisited the golden age of the Stingray.

By Verdad Gallardo | 2026-06-08 19:53:43


VIEW MORE
story-6
10 Ugly Corvettes That We Still Kinda Love

Slideshow: 10 ugly Corvettes that we still kinda love.

By Joe Kucinski | 2026-06-03 10:34:17


VIEW MORE
story-7
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer

A lot of money has changed hands at the online auction house over the years.

By Brett Foote | 2026-06-03 10:21:50


VIEW MORE
story-8
10 Things Every Corvette Owner Needs (2026 Edition)

Slideshow: 10 great gifts Corvette enthusiasts actually want for Father's Day!

By Michael S. Palmer | 2026-06-03 15:43:40


VIEW MORE
story-9
8 Most "Only Corvette Owners Understand" Quirks and Problems

Slideshow: These are the quirks, annoyances, and oddly lovable problems that every Corvette owner eventually learns to live with.

By Pouria Savadkouei | 2026-05-28 09:31:39


VIEW MORE