Set timing on a '99 Chevy 454 ? - 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 02-17-2008, 03:00 PM
Registered User
 
Join Date: Feb 2008
Location: Ohio
Posts: 3
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Set timing on a '99 Chevy 454 ?

Hi Folks, new to the forum so not sure if I'm where I'm suppose to be. OK here goes, I have a 1999 Chevy motorhome with the vortex 454 and I want to check / set ignition timing. Can't find any specs on it in the books I have nor online so far. Some earlier Chevy's required a harness to be disconnected or a wire to be grounded but can't find any info on this year. Plus I'd like to find out how much total timing the motor has and if it can be tweaked to get more if possible. I'm doing this to try and gain a bit of fuel mileage and use more of the motor's torque band rather than RPM's. When it hits a small grade now it just starts downshifting rather than hanging in there and pulling it. Any advise that you can offer will be appreciated.
Thanks, Jack from northern Ohio

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 02-17-2008, 04:21 PM
DoubleVision's Avatar
Not Considered a Senior Member
 
Last photo:
Join Date: Oct 2002
Location: Heart Of Dixie
Age: 40
Posts: 10,658
Wiki Edits: 0

Thanks: 15
Thanked 59 Times in 56 Posts
If the timing has not been altered theres not a issue with it, it downshifts likely because its tired or it's in need of a good tune up. Far as I know there is no timing adjustment in the traditional way of just moving the distributor.
But I have found a site that gives better detail than I can.
http://67-72chevytrucks.com/vboard/s...d.php?t=269518

When was the last time it was tuned up? was the best pieces used like spiral core spark plug wires? How many miles are on it? what kind of air filter? what kind of exhaust?
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 02-17-2008, 05:11 PM
Registered User
 
Join Date: Feb 2008
Location: Ohio
Posts: 3
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Chevy Timing

We live in Ohio and traveled to Florida around New Years. Before leaving I gutted the single exhaust (including the converter) and had dual exhaust made for it. I also ripped all the stock air cleaner out of the right front wheel well (it was collecting water there) and moved it forward under the front hood and put on a cone shaped K & N filter.
Before leaving on the return trip home (from FL) I did a complete tune up including wires, plugs, cap, rotor and fuel filter (didn't really need any of these parts). The coach has 15,000 original miles on it and isn't tired by any means. But I understand where your coming from and I forgot to include that information in the original posting. We're leaving for Denver here shortly and I have re-modified the air system, pulled the mass air flow and opened up the screening besides adding a trans shift kit to help it hold the gears a bit longer.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 02-17-2008, 05:28 PM
carsavvycook's Avatar
My 2 cents worth
 
Last photo:
Join Date: Sep 2007
Location: Lakeside, CA
Age: 57
Posts: 2,855
Wiki Edits: 3

Thanks: 2
Thanked 2 Times in 2 Posts
Quote:
Originally Posted by moorwhine
Hi Folks, new to the forum so not sure if I'm where I'm suppose to be. OK here goes, I have a 1999 Chevy motorhome with the vortex 454 and I want to check / set ignition timing. Can't find any specs on it in the books I have nor online so far. Some earlier Chevy's required a harness to be disconnected or a wire to be grounded but can't find any info on this year. Plus I'd like to find out how much total timing the motor has and if it can be tweaked to get more if possible. I'm doing this to try and gain a bit of fuel mileage and use more of the motor's torque band rather than RPM's. When it hits a small grade now it just starts downshifting rather than hanging in there and pulling it. Any advise that you can offer will be appreciated.
Thanks, Jack from northern Ohio
The timing is computer controlled. To set it you need to have a scan tool hooked up to the diagnostic connector. The scan tool needs to have a set procedure program in it. It will instruct you to synchronize the cam and crank sensors (engine running) by pushing the throttle to full throttle. It will then show the distributor timing degree #. It must be within 2 degrees of zero.

If it does not go full throttle to synchronize you either have a worn accelerator cable, or bent gas pedal assembly. This has to be done with the engine hot and in closed loop. That is also a split year for another timing setting procedure. The other one is to unplug the single wire tan/black GM service pack connector. It is located on the wire loom within 6 inches of the distributor. Disconnect it and set the timing to 0 degrees. The computer will take care of the rest. Just make sure you replace the fuel filter once a year whether you put 30,000 miles on it or not. Condensation accumulates in the tank and causes fine particle's of rust that plug filters quickly.

Hope this helps.
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 02-17-2008, 05:32 PM
carsavvycook's Avatar
My 2 cents worth
 
Last photo:
Join Date: Sep 2007
Location: Lakeside, CA
Age: 57
Posts: 2,855
Wiki Edits: 3

Thanks: 2
Thanked 2 Times in 2 Posts
I forgot to mention you can get a aftermarket programmer to increase you pulling power. There are a lot of good ones out on the market now, and the prices are starting to drop because of competition.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 02-17-2008, 08:14 PM
Registered User
 
Join Date: Feb 2008
Location: Ohio
Posts: 3
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
set timing on 99 Chevy

Thanks to those who replied back to my question. Great site and your time and replys are much appreciated! It has given me additional thoughts on which to move further forward with this beast. I took my 1993 33' motorhome from 7.5mpg to over 9mpg towing the same vehicle with also running a 454 motor. This vortec 454 is proving to be a much more difficult mountain to climb. It runs like a scaled dog even dragging the Saturn along, it just doesn't want to release the crappy fuel mileage. I'll continue to tinker with the thing but have to admit its won the first 3 or 4 rounds!
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 02-17-2008, 08:56 PM
carsavvycook's Avatar
My 2 cents worth
 
Last photo:
Join Date: Sep 2007
Location: Lakeside, CA
Age: 57
Posts: 2,855
Wiki Edits: 3

Thanks: 2
Thanked 2 Times in 2 Posts
The only other option other than a computer programmer would be a adjustable fuel pressure regulator.




Good Luck
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 02-17-2008, 09:10 PM
SAATR's Avatar
Member
 
Last wiki edit: Header design
Last journal entry: And still more pics...
Last photo:
Join Date: Dec 2003
Location: Shreveport, LA
Age: 29
Posts: 247
Wiki Edits: 1

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
The timing is computer controlled. To set it you need to have a scan tool hooked up to the diagnostic connector. The scan tool needs to have a set procedure program in it. It will instruct you to synchronize the cam and crank sensors (engine running) by pushing the throttle to full throttle. It will then show the distributor timing degree #. It must be within 2 degrees of zero.
Quote:
If it does not go full throttle to synchronize you either have a worn accelerator cable, or bent gas pedal assembly. This has to be done with the engine hot and in closed loop. That is also a split year for another timing setting procedure. The other one is to unplug the single wire tan/black GM service pack connector. It is located on the wire loom within 6 inches of the distributor. Disconnect it and set the timing to 0 degrees. The computer will take care of the rest. Just make sure you replace the fuel filter once a year whether you put 30,000 miles on it or not. Condensation accumulates in the tank and causes fine particle's of rust that plug filters quickly.
x2

The first procedure you'll need some fairly specialized equipment for, and unless you have a friend with a proper scan tool, it's best left to a shop. The second is the same procedure used for the tbi sbc and v6 trucks of the early 90's.
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 02-20-2008, 09:56 AM
Registered User
 
Last photo:
Join Date: Dec 2006
Location: Kansas City MO
Posts: 99
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
CAMSHAFT RETARD OFFSET TEST
The ignition timing cannot be adjusted. The distributor may need adjusting to prevent crossfire. To insure proper alignment of the distributor, perform the following:


With the ignition OFF, install a scan tool to the DLC.
Start the engine and bring to normal operating temperature. IMPORTANT: Cam Retard Offset reading will not be accurate below 1000 RPM
Increase engine speed to 1000 RPM .
Monitor the Cam Retard Offset.
If the Cam Retard indicates a value of 02 , the distributor is properly adjusted.
If the Cam Retard does not indicate 02 , the distributor must be adjusted.
ADJUSTING CAMSHAFT RETARD OFFSET


With the engine OFF, slightly loosen the distributor hold down bolt. IMPORTANT: Cam Retard Offset reading will not be accurate below 1000 RPM
Start the engine and raise engine speed to 1000 RPM .
Using a scan tool monitor Cam Retard Offset.
Rotate the distributor as follows:
4.1. To compensate for a negative reading, rotate the distributor in the counterclockwise direction.
4.2. To compensate for a positive reading, rotate the distributor in the clockwise direction.

Repeat step 4 until 02 is obtained.
Turn the ignition OFF.
Tighten the distributor hold-down bolt to 3 N.m (25 lb. ft.) .
Start the engine, raise engine speed to 1000 RPM and recheck Camshaft Retard Offset.


Quote:
Originally Posted by moorwhine
Hi Folks, new to the forum so not sure if I'm where I'm suppose to be. OK here goes, I have a 1999 Chevy motorhome with the vortex 454 and I want to check / set ignition timing. Can't find any specs on it in the books I have nor online so far. Some earlier Chevy's required a harness to be disconnected or a wire to be grounded but can't find any info on this year. Plus I'd like to find out how much total timing the motor has and if it can be tweaked to get more if possible. I'm doing this to try and gain a bit of fuel mileage and use more of the motor's torque band rather than RPM's. When it hits a small grade now it just starts downshifting rather than hanging in there and pulling it. Any advise that you can offer will be appreciated.
Thanks, Jack from northern Ohio
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 05-16-2012, 05:08 PM
Registered User
 
Join Date: May 2012
Posts: 4
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Hey im new to the site but had a suggestion if you still have problem. You said you took the screen off in front of the mass airflow, put that back on. Its specifically designed to control how the air flows across the sensor, if its not reading correctly it wont run as it should guaranteed
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
Chevy 454 overheating no matter what I do rakundig Engine 26 02-13-2011 04:03 PM
Chevy 292 Timing Question BIG292 Engine 9 07-29-2007 09:58 PM
EFI manifold from a '99 chevy 454 vortec dough88 Engine 0 05-26-2007 03:22 PM
1987 chevy tbi timing? hiball Engine 1 04-19-2007 02:10 PM
having trouble figuring out where to set ign timing, fast68 Engine 34 02-03-2006 06:49 AM


All times are GMT -6. The time now is 06:43 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.