87 GN pings while hitting 2 red boost lights

copo

Member
Joined
Apr 25, 2003
This week when I took out my 87 GN and hammered on it, it started to ping bad at high RPM and both red boost lights are lit. The same thing happens if I floor it on the highway at any speed when the RPMs climb and so does the boost to dual red leds. Before it used to hit 1 red then it would shift into the next gear with the RPMS climbing wihout any pinging.

Any thoughts what I need to adjust? Would this be caused by a sticking waste gate rod. My GN is all stock and is stored in the winter months.

I filled up with clean Shell 91 premium with zero ethanal and it still pinged. I haven't tried going back to Sunoco 94 but also noticed that Petro Canada has 94 octane here now. But I don't think the 94 will help here if I'm hitting the double red boost lights. I have to let off when I hit the 1st red boost led light so it doesn't ping.
 
Get the higher octane in there. Or you will become an expert at replacing head gaskets.
 
Both the led tachometer and boost gauge are notorious for being out of calibration after 24 years. Don't trust them.

Mine was off 1500 rpm and boost was off by 5-6 psi.
 
Thx, I'll use up the 15 bucks I put in the other day and go back to using 94 but I'll try Petro Canada 94. I hear too many people with new trucks experiencing engine chuging at WOT due to the increased amount of corn Sunoco is using here in Canada. I use nothing but Shell 91 with 0 ethanal on my mowers, weed eater and snow thrower and my 70 Z28.
 
Any thoughts what I need to adjust? Would this be caused by a sticking waste gate rod. My GN is all stock and is stored in the winter months.

Something you might want to consider if you are still running the stock chip is getting a more modern upgraded one. Alot of members here use the turbotweak chips with great results. Here is a link to their website.

TurboTweak Home
 
It was the hose off the waste gate T and the hose going to the passenger valve cover. I'll have to go to the dealers and see if they have the shaped hose, otherwise it's 3/8"OD and 1/4"ID.
 
Overboost + 91 oct= melted pistons. How's that for Turbo Buick math. Do yourself a favor and get a real boost gauge and a Scanmaster...
 
Both the led tachometer and boost gauge are notorious for being out of calibration after 24 years. Don't trust them.

Mine was off 1500 rpm and boost was off by 5-6 psi.

try a boost gauge.i wouldn't trust the stock gauge at all. when mine was stock it would peg both gauges before it shifted to 2nd gear. wire ties on the vacume line won't hurt either
 
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