1990 454 with no compression in 4 cylinders? - 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
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 01-26-2011, 06:24 PM
Registered User
 
Join Date: Jan 2011
Location: El Mirage, Arizona
Posts: 2
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
1990 454 with no compression in 4 cylinders?

What I Have Is a 1990 Chevy C3500 Longbed Extended cab 2 wheel drive 1 ton pickup. The other day i had a really bad back fire it killed the engine , i puled over fired her back up and drove her home. The next day on my way to work it did it again but not as bad, except this time it didnt start at all , I had to be pulled home. once i got it home it still wouldnt start,No spark? so i replaced the ignition control module, It started and idled fine after that, after about 10 minutes the truck wasnt running for ****, rough idle and bad miss. so after this i checked compression in all cylinders, driver side had about 70 psi per cylinder and passenger side none whatsoever, checked to see if all pistons were stil moving when engine is cranked over and they are !. so today i pulled the valve cover and intake, nothing out of usual, Maybe i have a blown head gasket? theres no water in oil either.

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 01-26-2011, 06:33 PM
cool rockin daddy's Avatar
1.21 giga-watts???!!!!
 
Join Date: Aug 2003
Location: wherever cool cars are
Posts: 1,535
Wiki Edits: 0

Thanks: 0
Thanked 3 Times in 3 Posts
Flattened cam lobes?
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 01-26-2011, 06:38 PM
cobalt327's Avatar
WFO
 
Last wiki edit: Intake manifold
Last journal entry: 1980 Malibu Wagon
Last photo:
Join Date: Mar 2009
Location: Atlanta
Age: 59
Posts: 5,037
Wiki Edits: 1616

Thanks: 128
Thanked 597 Times in 546 Posts
There's a chance the timing set has given up the ghost. Either by jumping time a couple or more teeth- or it broke the chain completely

The first thing I would do is to crank the engine and watch the rockers. If they're still moving, you need to set the engine to TDC using the timing line on the balancer and the timing tab.

Then remove the distributor cap and see if the rotor is pointing at #1 or #6. Mark the position of #1 and #6 on the distributor BODY, using the cap as a guide.

With the timing marks at TDC, the rotor should be just after the marks you made. If the rotor is pointing elsewhere, suspect the timing set has jumped time.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 01-26-2011, 06:50 PM
Registered User
 
Join Date: Jan 2011
Location: El Mirage, Arizona
Posts: 2
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Even If It did break the timing chain would it still run? cause before i tore it all down it was running just very poorly i even drove it like 5 or 6 miles before i tore it down, and from what i can see on the cam the lobes arent worn,
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 01-26-2011, 07:59 PM
cobalt327's Avatar
WFO
 
Last wiki edit: Intake manifold
Last journal entry: 1980 Malibu Wagon
Last photo:
Join Date: Mar 2009
Location: Atlanta
Age: 59
Posts: 5,037
Wiki Edits: 1616

Thanks: 128
Thanked 597 Times in 546 Posts
Quote:
Originally Posted by Garrett.m12
Even If It did break the timing chain would it still run? cause before i tore it all down it was running just very poorly i even drove it like 5 or 6 miles before i tore it down, and from what i can see on the cam the lobes arent worn,
If the chain was broken it wouldn't run at all. It still may have jumped time. Follow the sequence I wrote above and you will know if that is, or is not, the problem.

If you have the engine apart far enough to see the timing chain and gears, rotate the engine CW as you face it from in front of the radiator to get the two alignment dots on the timing gears as close to each other as possible.

This will be: crank gear dot at 12 o'clock, cam gear dot at 6 o'clock.

If you find that the dots will not align perfectly, you will know the chain has skipped. Plus the chain will be loose, the cam gear may even show considerable damage. The crank gear usually survives this w/o showing anything.

Good luck.
Reply With Quote Quick reply to this message

Recent Engine 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:
If you do not want to register, fill this field only and the name will be used as user name for your post.
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
Gas in #7 and #8 Cylinders Florida Camaro Engine 15 10-05-2009 01:16 PM
New... with 100% more cylinders! 5_speed Introduce Yourself 15 12-25-2008 05:15 PM
4 Cylinders oshermo Introduce Yourself 1 11-26-2005 02:11 PM
new brake cylinders to 1990 pickup HzSandman Suspension - Brakes - Steering 1 05-10-2005 04:47 AM
Not using all the cylinders? alex_0227 Engine 15 03-28-2005 01:06 PM


All times are GMT -6. The time now is 03:02 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.