Truck will randomly shutoff while driving.

I have a 1990 Chevy c1500. 350 700r4. I’ve been having this issue of it shutting off while driving like the key was turned. The first time it happened it wouldn’t start until it sat for awhile. I replaced the ecm map sensor and fuel pump. Before this I’ve replaced the TPMS and the IAC. The other night it happened again but it will start. It’s now showing codes 22 and 42.

1997c1500 said:

It’s now showing codes 22 and 42.

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Don't see your 90 emissions manual..
Maybe look at the 91..
page 1365 looks like where code 22 is...TPS
and code 42 down below....EST
Can't imagine it wouldn't be helpful....

scott2093 said:

Don't see your 90 emissions manual..
Maybe look at the 91..

88-98 Service Manuals

Over the years I have collected a bunch of GM service literature. Links to PDF Scans of service and STG manuals and a links to the Parts manuals. You'll need the FREE Adobe Acrobat reader to open these files. Get it directly from Adobe here {http://get.adobe.com/reader/} If you're not...

www.gmt400.com

page 1365 looks like where code 22 is...TPS
and code 42 down below....EST
Can't imagine it wouldn't be helpful....

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I have a book that came with the little tool and tells me what the codes mean.

1997c1500 said:

I have a book that came with the little tool and tells me what the codes mean.

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The factory manual will have theory of operation and troubleshooting steps to determine what to do next. Mentioning the codes was more just a courtesy for others to chime in in case they forgot...lol