Knock During Powerbrake Start

[tomjon]

Possible causes? None on knock gage during hard start with no boost. '86 GN has street chip (maker unknown), 93 octane gas, stock turbo that max's out at 17.5 psi. Thanks.

 

[Steve Wood]

Wheel hop, downpipe hitting control arm or pinchweld on lower firewall

 

[Sinful6]

Yup, wheelhop.

 

[tomjon]

Thanks for the info. Wheel hop must be causing engine rocking, right?