99 Tahoe 5.7 vortex P0300 code HELP
- Thread starter Mackb23
- Start date
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It's running lean based on your short-term fuel trims (fuel is being added -- a lot!). One possibility is a vacuum leak, or something else could be causing that. Check the intake from the MAF to the throttle body to be sure there aren't any leaks in that plumbing. It could be a hose left unplugged, or damaged.
I’ll definitely take a look at that in the morning! I appreciate it.
Hoesgottaeat2
Full Access Member
Did the new motor come with new ignition components?
My '99 Hoe had a P0300 and it wound up being a bad distributor cap, that was replaced just months before the issue arose.
The new cap resolved the issue immediately.
My '99 Hoe had a P0300 and it wound up being a bad distributor cap, that was replaced just months before the issue arose.
The new cap resolved the issue immediately.
It did not come with anything but I did replace the distributor cap and rotor, along with new plug wires and plugs
I’m also having multiple misfires on 1 and 5
Multiple parts on this series of trucks-most aftermarket parts don't work or not very long.
The first on my list- Dist cap/rotor. Use only Delco, Delphi, or United DCR820x only. Packard Wires a help also.
Gmt 400 trucks do not like certain aftermarket parts.
First on my list is Dist cap/Rotor- Use only Delco/Delphi, or United DCR820x. Packard wires a help too.
Looking at fuel trims- 1st do an idle leak check using carb cleaner around intake. 2nd- fuel pressure check, Best is a 6 foot fuel hose and stick Gauge under wiper. Report findings here. We're here to help.
Looks like a vacuum line, but I wouldn't mind seeing a pic of where it is on the engine.
