1984 gmc diesel starting problems

1984 GMC SIERRA
129,000 MILES • V8 • 2WD • MANUAL
Avatar
JMHAMBRIGHT
  • MEMBER
  • 5 POSTS
we have a 1984 gmc sierra classic 6.2l diesel when we can get it to run it smoke badly, but the problem we have it getting it to start we have put new diesel in it replaced the glow plugs,the glow plug controller, the alternator,the thing that looks like a solenoid but controls the glow plugs, both batteries twice now and used starting fluid and we cannot get it to start, also the batteries got hot last time we tried to start the truck and we then took the batteries in and replaced them both because they both had hardly any charge on them and no cold cranking amps.could you please help us if possible. thank you,J
Aug 23, 2011 at 6:20 PM
Advertisement
Avatar
MHPAUTOS
  • ✓Experienced Mechanic
  • 31,937 POSTS
What colour is the smoke? black or white?
Aug 25, 2011 at 12:45 AM
Avatar
JMHAMBRIGHT
  • MEMBER
  • 5 POSTS
the smoke is whitish gray
Aug 25, 2011 at 11:49 AM
Avatar
MHPAUTOS
  • ✓Experienced Mechanic
  • 31,937 POSTS
This can be due to low compressions causing incomplete combustion, do a compression test.
Aug 25, 2011 at 3:31 PM
Avatar
JMHAMBRIGHT
  • MEMBER
  • 5 POSTS
If I could get it to run I will do that do you have any idea by I cant get it started by the description I gave you.
Aug 25, 2011 at 5:08 PM
Avatar
MHPAUTOS
  • ✓Experienced Mechanic
  • 31,937 POSTS
A diesel will not start with low compressions, these are compression ignition engines, they rely on good compression to fire and run.
Aug 25, 2011 at 7:32 PM
Avatar
JMHAMBRIGHT
  • MEMBER
  • 5 POSTS
ok now I understand,what can I do besides the compression test to fix this problem does this mean my engine needs to be overhauled or replaced if it is showing low compression after the test.
Aug 25, 2011 at 8:18 PM
Avatar
MHPAUTOS
  • ✓Experienced Mechanic
  • 31,937 POSTS
Lets see what the comp test shows, then we can decide on what the next step is.
Aug 26, 2011 at 1:05 AM
Avatar
JMHAMBRIGHT
  • MEMBER
  • 5 POSTS
ok thx
Aug 26, 2011 at 10:42 AM
🔧 Tools & Auto Repair Parts
Find automotive tools, diagnostic equipment, and replacement parts for your next repair.
Shop on Amazon →
Paid affiliate link. As an Amazon Associate, we earn from qualifying purchases.
Add a reply
Join 2CarPros for free, one of the most advanced car repair communities on the internet. From first-time drivers to seasoned mechanics, everyone is welcome to reply, share details, and get better answers. You can add a temporary image or video first; uploads are limited to 20 MB.

Ask a new question

Frequently Asked Problems for This Vehicle