94 Buick RoadMaster Estate Wagon LT1/ TPI question - Page 6 - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans Advertise
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Engine> Modern Electronic Engines
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #76 (permalink)  
Old 06-27-2019, 12:07 PM
Registered User
 
Join Date: Apr 2007
Posts: 12,271
Wiki Edits: 0

Thanks: 166
Thanked 1,088 Times in 869 Posts
Toward the end of my OBD 1 computer I had to reboot so much I put a switch in the dash so I could just turn the power off to it when ever I shut down. I finally just made a permanent conversion to a carb rather than do any more fixes to the computer system.

A problem you have with the Buick is it isnt exactly an OBD 1 and it isnt an OBD 2 but it is a little of both.

You've been through exhaust leaks, possible sensor failures and replacements, most everything yet the problem persists. I'm thinking that like my old OBD 1 it's getting down to the computer itself having brain farts. These things don't last forever. It didn't die suddenly it just got increasingly haywire hardly noticeable at the start but enough that since I design these systems for aerospace I knew from experience that it was starting to die. As a step alng the way it turned out the 4l60E died the 3/4 clutch death so I replacd it with 700R4 which didn't need the computer. The computer over the next couple years got flakier and flakier. So did my heart so I had to take time out for a ring and valve job on that, so in the latter months of recovery I went to the shop and replaced the EFI with a carb and intake. If nothing else that simplified the underhood wiring mess of GM's.

I had to relearn how to operate a carb, no more just turn the key and it starts, the fuel mileage isn't as good, I can duplicate the mileage of the EFI but you have to work at it, it doesn't just happen. The down side is that isn't much fun.

The LT 1 and 4 can be converted to a carb and conventional HEI with a GMPP carb intake. It is possible to retain the 4L60E with a throttle position sensor and tach signal to the computer if it still knows how to shift gears in its old age.

Bogie

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #77 (permalink)  
Old 06-27-2019, 05:38 PM
LATECH's Avatar
Hotrodders.com Moderator
 

Last journal entry: GTO Reproduction Hood
Join Date: Jul 2010
Location: Northeast Pennsylvania
Posts: 7,708
Wiki Edits: 0

Thanks: 547
Thanked 833 Times in 712 Posts
When I worked at CHEVROLET in the late 80s and early 90s we considered an injector cleaning to be periodic maintenance.More so than a tuneup. Fuels were borderline sludge and injectors were finicky.

We would hook the alternative fuel/detergent supply to a warmed up engine and start it.Prop the throttle at 2500 rpm and stand back and listen for a few minutes. You could hear cylinders changing tune as they fired, misfired and eventually cleared up. At the end it wasnt uncommon to have the engine running at 3000 rpm or a bit higher due to the improvement that cleaning made.

It isnt changing parts, it is just cleaning what you have . You should try it.
__________________
Fact is stranger than Fiction
Reply With Quote Quick reply to this message
  #78 (permalink)  
Old 06-28-2019, 10:53 AM
bentwings's Avatar
bentwings
 
Join Date: May 2002
Location: St.Paul, Minn
Age: 77
Posts: 2,553
Wiki Edits: 0

Thanks: 8
Thanked 229 Times in 195 Posts
In my quest for knowledge on this system I came across “smoke testers” for leak detection. There are some videos and methods of use. Using the power brake port was a good one shown in static test.
There are commercial ones of various prices then some home made ones.
The pressures noted are very low....1-2 psi. Only 4” HG. It would seem to me that you would have to block the exhaust system on both sides and still have a very dense cloud to see anthing on the intake system.

Any comments?
Reply With Quote Quick reply to this message
 
  #79 (permalink)  
Old 06-28-2019, 02:44 PM
Registered User
 
Join Date: Apr 2007
Posts: 12,271
Wiki Edits: 0

Thanks: 166
Thanked 1,088 Times in 869 Posts
I'll go back to where i was yesterday, that being that computer chips don't last forever.

ROMs, EPROMs which are at the heart of these EFI and vehicle management systems have a reliable life span of 10 to 15 years, and that's measured in a benign environment like a building. Anything longer is an uncalculated gift of the computing gods. As these devices age out they just get forgetful resuluing in holes forming in their programming. Of the sensors that are sending data to the program that sums to an address that has fuel or timng data stored there and that location has lost function, you will see an error code genetated against the subject sensors. Another common event is the CEL comes on but will not read an error code, or the error code displayed makes no sense to the encountered problem. Back in my earlier aerospace days we used to joke that it was the function of "Built In Test Equipment" (BITE) to point to the other guy as causing the error. What that really gets down to is you as designer, tester, mechanic, or technican need to have a good view of the wider system and how the parts work together inorder to decipher the true meaning of the codes you see. This isn't an all the time thing but when the codes don't match what's happening, or fixes to the stated error don'tchange anything this is a good sign that the problem as stated isn't really the problem.

Think of it as Alzheimer for computers, I had an uncle that had thi (as a human); when he had to pee he went to the refrigerator to do this business. Shows you what living in Cleveland and working at the POC brewery all your life could do to you.

Bogie

Last edited by BogiesAnnex1; 06-28-2019 at 02:54 PM.
Reply With Quote Quick reply to this message
  #80 (permalink)  
Old 08-15-2019, 08:27 AM
bentwings's Avatar
bentwings
 
Join Date: May 2002
Location: St.Paul, Minn
Age: 77
Posts: 2,553
Wiki Edits: 0

Thanks: 8
Thanked 229 Times in 195 Posts
Boggie, you know we have done virtually everything
to the car/system, lately my guy and I discussed installing new injectors. We weighed the tests and what’s going on and what’s not going on. I hate throwing parts at these things and the more I get into the EFI the more I see this happening. The latest was a smoke tester top if the line thing to test for suspected leaks. It showed no leaks anywhere. Then another compression test..normal and another set of new plugs on the right bank. Still the same issue. The right bank is dead max rich.

So at this point we have no options but to start with the computer. So I have to apologize for taking your comments lightly. We have a guy coming over that reflashes these. Flames it happens more often than you think. I also discovered that Rockauto has rebuilt computers and the EPROM available. Hefty core charge too.

So I may have to go this route. It really gets under my skin as the car ran so good then just overnight it started acting up.
But like you said these things don’t last forever. Is just the testing frustration of ot being able to identify the issues.
Reply With Quote Quick reply to this message
  #81 (permalink)  
Old 08-22-2019, 10:33 AM
bentwings's Avatar
bentwings
 
Join Date: May 2002
Location: St.Paul, Minn
Age: 77
Posts: 2,553
Wiki Edits: 0

Thanks: 8
Thanked 229 Times in 195 Posts
The guy that does does the Reflash said he can’t do these. No reason given at this point.
I kinda lost it I guess, I just said fix the dam car, I need it quickly. I’m really tired of screwing around with it.
Virtually everything is pointing to the computer. What elas can it be? I did. Chat with a detailer and he said he no longer pressure washes cars under the hood. He did it on one and it acted like it had been submerged. Nothing ever really worked correctly. He said it cos,t him a fortune to fix it.

The new computer is on the way complete with the new EPROM. Hopefully by the week end.

Meanwhile my Quadrajunk el Camino just purrs on. It starts instantly cold or hot doesn’t get very good mpg but at least I get there. I have two of them on the boat that I just don’t have time to go through so I’m taking them to The Carb shop. A nationally know carb rebuilder. He said he could turn them around pretty quickly.
Reply With Quote Quick reply to this message
  #82 (permalink)  
Old 08-22-2019, 07:38 PM
Registered User
 
Join Date: Jun 2018
Posts: 33
Wiki Edits: 0

Thanks: 0
Thanked 4 Times in 4 Posts
Quote:
Originally Posted by bentwings View Post
The guy that does does the Reflash said he can’t do these. No reason given at this point.
I kinda lost it I guess, I just said fix the dam car, I need it quickly. I’m really tired of screwing around with it.
Virtually everything is pointing to the computer. What elas can it be? I did. Chat with a detailer and he said he no longer pressure washes cars under the hood. He did it on one and it acted like it had been submerged. Nothing ever really worked correctly. He said it cos,t him a fortune to fix it.

The new computer is on the way complete with the new EPROM. Hopefully by the week end.

Meanwhile my Quadrajunk el Camino just purrs on. It starts instantly cold or hot doesn’t get very good mpg but at least I get there. I have two of them on the boat that I just don’t have time to go through so I’m taking them to The Carb shop. A nationally know carb rebuilder. He said he could turn them around pretty quickly.


Hey I'm not wanting to hijack this thread but I wanted to share my experience and help I got from this thread, I just rebuilt my 94 chevy 5.7 in my k1500 z71, made it into a mild 355 and it runs great, anywho I was experiencing some weird things kina like what you have had going on and couldn't pin it down to one thing it kept messing up and idling extremely rough and missing and then it would just suddenly clear up and be fine, I'd think it was all fixed, and then a couple days later it would do it again and throw in some new wacky stuff just to make it interesting, I got a cable and using aldldroid I checked just to see if there was anything noticeably wrong or if it would give me a code but it all seemed peachy. Well after reading bogies post about "crusty" computers I thought well I could try it, as I'm wanting to tune it myself down the road I figured it would be good to start with a fresh computer anyway. Found a company on Ebay that reflashed them, swapped memcals, plugged it in and bam! Usually it would turn over for a couple seconds before firing off but not tonight, I hardly hit the starter before it went off and ran so beautifully, no miss no rough idle, no weird hunting anymore. So far I'm very happy and I hope that fixes your problem. Thanks bogie and all the guys on here with the great info
Reply With Quote Quick reply to this message
  #83 (permalink)  
Old 09-02-2019, 11:13 AM
bentwings's Avatar
bentwings
 
Join Date: May 2002
Location: St.Paul, Minn
Age: 77
Posts: 2,553
Wiki Edits: 0

Thanks: 8
Thanked 229 Times in 195 Posts
I hope that happens tomorrow when I stop by or call the shop. Somehow I have a gut feeling it’s more of the same.

I did find my laptop and scanning cable so I can deep scan right away. I think I’ll bring it along so I can compare scans. If irs running great I’ll be sooo happy.
Reply With Quote Quick reply to this message

Recent Modern Electronic Engines 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:
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:
Insurance
Please select your insurance company (Optional)

Log-in



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
what engine? 77 buick estate wagon roadlet_411 Engine 15 04-27-2010 09:29 PM
1962 Buick Electra 225 LT1 Swap crazycasey General Rodding Tech 1 02-05-2010 04:00 PM
b or g hemi joe Body - Exterior 5 05-03-2009 02:50 PM
'96 roadmaster LT1 compatibility HOUCKXLR8 Engine 9 04-17-2007 10:43 AM
Buick Roadmaster stanray Introduce Yourself 2 02-06-2007 06:06 AM


All times are GMT -6. The time now is 11:54 PM.


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.