smashed plug

[68442]

1990 laser that is all stock except a few free mods and a mbc. Car runs great until you get into 12psi of boost. It then bends the #1 spark plug's electrode. I assume this is from running cheap 89 fuel? I must be getting some detonation. Bend the tip back and it runs great again(27mpg). This is going to the father in law and I doubt he'll rod on it. I warned him not to floor it unless he has good fuel in it. Would putting some BPR7ES in there instead of BPR6ES help?

I have yet to do a boost leak check, the timing on it is set correct. Compression test all equal. I suspect the fuel but any other suggestions to check would be great. Probably do the boost check tomorrow.

Thanks!

 

[WarSaw]

Excessive detonation can bend the arm on the spark plugs. On a turbo car though I wouldn't recommend running 89 octane anyway though.

 

[68442]

With the dish pistons I knew it wasn't them. I agree, no cheap gas anymore for messing around This car is a touchy bastard.

 

[68442]

I'm starting to wonder if its not a fuel delivery problem. Only #1 is getting the problem and #1 is the last cylinder to get fuel from the rail. Might have to do some fuel checks.

 

[bastarddsm]

I'd get a walbro 190 and a fresh fuel filter. The pump is probably dieing..

 

[4g63Powered]

Get some 91+ in it ASAP, and see if it still happens. And don't boost on the low-grade, or you risk more damage than a bent sparkplug.