Mechanics

HAVING HESITATION PROBLEMS OFF IDLE AND WHEN CRUISING AT 60 MPH CAR IS SURGING

1993 Nissan Serena • 170,000 miles

Installed new egr valve, new bpt valve, new egr solinoid and new exhaust temp sensor. Also new oxygen sensor, new plugs, cap, rotor, air filter, new fuel pump and fuel filter, new iacc valve, all new injectors. Problem goes away if I unhook egr valve vacumn hose. It feels like egr is opening too far.
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Karlandee
March 2, 2012.



EGR seems to be opening too long. Have you tried cleaning the EGR passages?

KHLow2008
Mar 2, 2012.
Yes I cleaned all egr passages and checked to make sure I was getting exhaust out of all passages and tubes.

Tiny
Karlandee
Mar 2, 2012.
Something is telling the computer to keep the EGr opened for longer than necessary and it could be the O2 sensor. If the sensor is not OEM, it can cause such problems.

The other thing to check would be the PCM and MAF. Ensure the TPS is working correctly

KHLow2008
Mar 3, 2012.
Yesterday I bought a brand new bosch oxygen sensor and the car has alot more power but still hesitates. I will check the tps and maf tommorow, Thankyou, KARL
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Tiny
Karlandee
Mar 3, 2012.
Just installed new tps and adjusted- car runs better and no surging at 60 mph but still hesitates off idle at stop signs.

Tiny
Karlandee
Mar 3, 2012.
Did you clean the throttle body?

KHLow2008
Mar 3, 2012.
Yes I cleaned it completly.

Tiny
Karlandee
Mar 3, 2012.
Did you check the ignition timing and valve clearances?

What about the MAF?

KHLow2008
Mar 3, 2012.
Timing is set to 10 degrees and vavles have been adjusted, MAF is next on the list. Thankyou for all your help, KARL

Tiny
Karlandee
Mar 3, 2012.

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