OK. I need some advice on my 6 cyl 96 SE.
Last week I had the ARG vallve replaced, new sparks and wires and a new manifold cover and seals replaced,amomg other things. My Bonneville had been starting real hard and running rough after driveing a while. When I would first start in the morning,it would turn right over. After driving a while,and parking,it would be very hard to start,and when it did,it would almost stall out and then catch.
I had alot of work done, hoping this would solve the problem.
It'* still doing the same hard start routine, now the check engine light is on,and it stalls when idling for a while,and this afternoon it stalled in the garage when i put in in park.
This is frustrating.as you can guess. I'm taking it back to the mechanic in the morning to be looked at. I took it back already, and he ran a full diagnostics test...fuel,computer,electrical,etc. but could find nothing.
Any ideas?
Please let me know.
She'* only got 80000 miles on her.
Just remembered one more thing.......I filled up on Chevron Techron Supreme as always...put the trip counter to zero.....have gone through a half tank and have only driven 55 miles. Somethings up.

What'* an ARG valve? Never heard of that one.

You shouldn't waste your money on Supreme (premium) fuel. It'* of no benefit to you if your car isn't supercharged.

Have you scanned for codes? What'* your coolant level like? Can you test your coils using the procedure in Techinfo?

I'm not good at Bonneville advice, but all I can say is that my car'* had my mechanics stumped for 2 days because it won't start consistently (and it stalled on me before). They've thought of/ replaced everything: crank sensor, starter, fuel pump, coils... They've even gone through multiple sensors to make sure, still haven't figured it out. I guess what I'm saying is when you know something, tell me!

Thanks for the reply willwren....coolant level is fine...had the system flushed as it was in the shop....mechanic replaced it with green,not pink which made me wonder. He said green was actually better for the engine than GM pink. Yeah it turned my head too.
ARG valve has something to to with emission he said, it blew off when it back fired originally taken to repair.

I think AGR = EGR

Well,sorry about the mistake. I thought I could ask for some advice,and not an insult.

would a Bosch valve cause problems, like reported with the Bosch 02 sensors?

Who said anything about a Bosch valve?
How are your battery cables by the way?

You know how the Bosch 02 sensors often cause problems? Well, if the EGR was replaced with a Bosch one could that cause a problem? I'm over my head here so idk.

Hi and welcome..

No biggie on the AGR vs EGR.. Being an online forum WillWren may not have understood what you meant. Since you aren't the gearhead like us.. do you have your receipt to refer to? You mention a manifold cover, I'm thinking that the upper intake manifold was replaced, need you to confirm though.

No worries if the EGR is Bosch or not.

We'll need you to go to an Autozone or another auto chain where they can scan your car for codes. Get the codes, don't buy any parts and come tell us what the codes are. We'll have a much better understanding once we know what the car is seeing for issues.

Meanwhile some things to think about are when the last time a general tune up was done, including:
O2 sensor
Plugs
Wires
Fuel filter

And if you have the ability to have the fuel pressure tested. Although if you had issues and the upper manifold was replace, the plugs/O2 sensor could be the culprits. The codes will tell the story.