Check engine light after sudden acceleration

[scottmech]

Hey guys new to the forums here.

Just picked up a 2000 Chevy 3500 dueally crewcab, 6.5TD automatic, 138,000 miles. Had it about a week so far and love the truck. Truck was well used, but not abused. Best I can tell it was a 1 owner/driver truck.

Truck starts great, runs/shifts great, no smoke, normal fuel mileage for the gear it has.

If I'm sitting still, then nail the throttle and stay into it at least till it gets into second gear, the check engine light comes on about 30-60 secnds later. Doesn't matter if it's 1/4 or full tank of fuel. Truck still runs the same whith cel illuminated, no perfomance degridation noted.

If I don'trepeat the above scenario during the next 2-3 start/stop cycles, the light will go out....but will return if I get into the throttle again.

No other lights come on (WIF, Throttle, etc), and best I can tell, the truck is completely stock (one of the reasons I bought it).

Just wondered if anyone has run into this before. Next step will be scanning it to get codes, but just hoped to get some preliminarry info from the pros before I get into this.

Thanks.

[charliepeterson]

Scanning for codes will tell you. Try looking out the right side mirror when you drop the hammer. Heavy black smoke is a sign of no boost pressure. This will turn on the SES light.
Near the top of this page if you hit the "search" feature and type in a phrase your looking for it will give you lots of direct hits on your subject. Otherwise come back here and we'll help you.

[chickenhunterbob]

As per Charlie,

If you have a SES light come on while driving, you will have a code set in the system, almost for certain.

For your year of truck, you need a scanner or code reader of some sort to determine which particular code, and which particular subsequent system to aim your troublesooting effors to.

In the US, apparently a place called "Autozone", and perhaps others will read codes free of charge. That is your best starting point.

Vacuum related is a good bet, first order of business to check air filter, but have the codes read before you go changing any parts.

Good luck and keep posting, you will find all the help you need here!

[scottmech]

Thanks guys.

As for smoke on acceleration, there is some black smoke, but not like a black fog screen that you can't see through. To me it looks normal...like it's running slightly richer at full throttle.....sort of like a fuel injected gas engine.

Noticed that after dropping the hammer, the truck accelerates, then after another few seconds I feel another small burst of acceleration.....almost like theres a delay in the turbo spooling up. Will need to hook a boost gage up to verify that though.

Havn't hooked a boost gauge up yet, but will do after I get the codes read, will also look at boost reponse during a hard launch and see what I get.

[scottmech]

Got the codes...PO236

Just did a search and found a good troubleshooting thread on this code.

Vacum from the pump is a 23-24 in as measured at the wastegate vacum solenoid...so the pump is good.

Also checked the line going to the wga from the wvs.... my handheld vacum pump will hold steady vacum (no leakage), and the wg arm moves and operated like it's supposed to. So it seems all the vacum lines/actuator diaphram are in good order.

Next step is to replace the wvs. Ordering one this afternoon to see what it does.....

[ 07-07-2005, 07:06 AM: Message edited by: scottmech ]

[scottmech]

Installed the new solenoid.

Seems to have solved the problem. Have got on it hard a few times today and no SES.

Thanks for the help.