Ok, heres a really dumb question that I should know the answer to already, but...don't.
WTF is the difference in the 93 octane tune, and the 87? I know it has something to do w/the timing(I've had it checked), but my valves are rattling like hell here lately (after I got my head gaskets replaced) and I wanna go down to the 87 tune, BUT don't wanna loose any power?? What are my options here, if I have any??
Any other suggestions I'd be more than happy to hear also.
Thankz
If you run the 87 tune you will lose power vs the 93 tune, the program has to pull some timing.
Are you saying that you have knocking on the 93 tune while running 93 fuel?
If that is true you might want to try a different brand of gas. I had a hypertech on a 97 GMC and it would knock if I used Amoco gas, but ran smooth on Citgo, both 93 octane. Maybe this helps a little, I'm sure someone else will chime in.
Jay
03 GMC ecsb Z71
Nelson Tune
Volant Intake
LS1 Fans
Before the head gaskets got replaced, it wouldn't knock, ping, whatever its doing at all. I've run Chevron, Amoco, BP, Citgo, just about everything imaginable. Would the valves be out of adjustment somehow?? I asked the guy at the shop, but he told me they adjust themselves...?
I've been running nothing but 93 octane since I bought the truck 2 years ago..and I've always used the 93 tune.
You had the head gaskets replaced ??
Couple things...
Thinner headgasket could be increasing compression...
or
Were the heads milled/shaved - were they warped ?
- Both would cause an increase in compression
or
carbon build up
Try a can of top engine cleaner - see if the ping goes away.
Follow the directions on the can
2003 LS 2wd ECSB 5.3 3.42 locking,
D&J Intake, 180F T-stat, Gibson Sport Truck system-replaced muffler w/ Race Truck muffler,
TB Bypass, ASP pulley, B&M 24k SuperCooler, Nelson Tune.
Hotchkis 2"/4" - IAS Rear Shocks
6,700 miles
AIM = Buyer Beware !!
http://members.cardomain.com/csherma1
Try changing your fuel filter first,you would be suprised how much a lean condition will cause ping detonation.
2003 GMC 5.3, RADIX 8#'s, GT7, 3.73 TRUTRAC. CORSA, YANK 2600, NELSON TUNE
excellent points csherma1
2002 ECSB 4.8L 3.73
The heads were checked, and were not warped, so I don't think they shaved them (for what I got charged they should have). They replaced the gaskets with a top-end kit they got from NAPA..I don't think it was a GM kit, so the thinner gasket you suggested I wouldn't doubt. I'll try the cleaner you mentioned first and see how that works, and also change the fuel filter. Thanks for all the help. If it doesn't work, I'm sure y'all will hear me bitching about it.
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