Mechanics

WHEN DRIVING DOWN THE ROAD THE VAN WILL START JERKING

2005 Chevrolet Express • 158,111 miles

I replace the camshaft positioning sensor I also replaced crankshaft positioning sensor I also replaced manifold absolute pressure sensor I replace mass air flow sensor all 4 oxygen sensors I replace spark plug & wires I replace distributor cap I replace rotor and I replace the distributor it all help but I steel have the same problem
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Benfaust
July 18, 2013.




4.3 v 6 E1500

Tiny
Benfaust
Jul 18, 2013.
Scan for codes and check fuel pressure first with a gauge

Hmac300
Jul 19, 2013.
No codes & fuel pressure maintain 62 pounds

Tiny
Benfaust
Jul 19, 2013.
Try cleaning the throttle plate on both sides with choke cleanerif it still does it have the injector professionally cleaned with either gm upper engine and ijector cleaner. Do not use the stuff you put in tank tis won't be strong enough. They have to hook up to fuel rail and clean that way.

Hmac300
Jul 19, 2013.
Today going to work jerking worse every time I stop at a red light it dies. Code finally came on p00300 multiple miss fire twice
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Tiny
Benfaust
Jul 19, 2013.
Multiple misfires are very hard to diagnose, have a pro scan it and freeze frame it to seeif anything is out of whack electrically. A lot of times sensors won't set a code but will read wrong voltage wise so they can try changing that part. One other thing if this has s K&N type filter on it clean it out but don't oil it, clean the maf and see if that helps. It's only with those type of filters not factory ones. You could check for a vacuum leak with choke cleaner as that can cause it as well then or if you have done this tuff do a compression checkon all cylinders. If there is a 20% variance on any of them then check to see why on the offending cylinder/cylindrs. Of cours it cold be ahead/intake gasket leak as well if you are losing coolant.

Hmac300
Jul 19, 2013.

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