Miss / lean condition only while cruising

super red91

Registered User
Driving WOT the car functions just fine. Driving with a partial load on the car it functions just fine. If I cruise (slight to no load) at 3k the car will randomly miss and feel like it slows up for a split second. At the same time I can notice my a/f gauge go extremely lean.

I've checked all grounds, cleaned maf, the car has new plugs and wires. There is no check engine light on. However I pulled codes and got the following:

159 - maf sensor fault, above or below normal.
157 - maf sensor fault, low voltage.
187 - fault in injector pulse width circuit / low
 
im thinking fuel pump mine acted up for a year before i put new pump mostly after run for an hour or so and would lift for an exit ramp it would die for a few seconds then pick up
 
Running the stock air filter? Checked it lately or re-oiled a K & N, etc?

Did you get the ground from the right motor mount to the frame?

Have a spare MAF you can swap in to test?
 
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Suspect turbulence in the MAF. Possibly pressure surges in the intake system causing backwash through the MAF or else road turbulence. A datalog would speak volumes.
 
I already swapped mafs with a known working one, inspected the wiring and all looked fine. Issue did not go away.

For grounds I have driver side motor mount to frame. Block directly to negative terminal on battery, and passenger side head to frame.

No stock air filter, 9" that's been on the car for about 2 years. Not in bad shaped but I guess I could clean that and see if it makes a difference.

I'd love to datalog but have nothing to do so, I'm behind on that one :eek:
 
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