Continuous Code 543 AGAIN
Hotshot
Joined: Jun 2015
Posts: 12,786
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Have you checked the connections at the relay as was suggested in this post and also in Post #2? This was the cause of stalling in my ‘89.
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Laughing Gas
Joined: Feb 2015
Posts: 765
Likes: 1
When I replaced the relay it looked fine, I'll likely replace it if I can find a quality version, same for the EEC relay socket.
Fleet Owner
Joined: Oct 2005
Posts: 20,785
Likes: 1,751
From: Kentucky
x2.....we have seen several threads where this was the root cause.
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Laughing Gas
Joined: Feb 2015
Posts: 765
Likes: 1
Update: Had the best guy I know look at it today, he was with me and drove it ~50 miles of varying conditions. The truck lost power ONCE, he seems to think it's electrical/wiring perhaps causing the ignition to cut out, doesn't seem to think the fuel supply is being interrupted at all. He told me to keep it and drive it through the week and if it resurfaces then to bring it back. 
Typical, the problem is absent when I'm trying to get the ****ing problem fixed. Goddammit I'm so frustrated with this thing ... 
Typical, the problem is absent when I'm trying to get the ****ing problem fixed. Goddammit I'm so frustrated with this thing ...
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Laughing Gas
Joined: Feb 2015
Posts: 765
Likes: 1
Bump. I'm back to getting 111 on both tests and the problem is back, nowhere near the garage. Go figure. Starting to go crazy over this. Need help.
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Fleet Owner
Joined: Oct 2005
Posts: 20,785
Likes: 1,751
From: Kentucky
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Laughing Gas
Joined: Feb 2015
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Hotshot
Joined: Jun 2015
Posts: 12,786
Likes: 2,423
EDIT: Found my receipt. Used the Interwebs to look up which part number was for which relay.
EC199 fuel pump relay connector
EC121 computer control relay connector
Fleet Owner
Joined: Oct 2005
Posts: 20,785
Likes: 1,751
From: Kentucky
That implies you should do the same...flip the sockets over to check for corrosion.
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Laughing Gas
Joined: Feb 2015
Posts: 765
Likes: 1
So have you or have you not physically looked at the wiring going into the relays? A week later and you didn’t find the relay connectors? Listed right there on Napa’s web site.
EDIT: Found my receipt. Used the Interwebs to look up which part number was for which relay.
EC199 fuel pump relay connector
EC121 computer control relay connector
EDIT: Found my receipt. Used the Interwebs to look up which part number was for which relay.
EC199 fuel pump relay connector
EC121 computer control relay connector