Tunned a GTP today
#1
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Tunned a GTP today
Today a 98 GTP came over for a tune. He said he got a dyno tune, cost him $700. After the tune he called them back and said the cars not running right. That will cost you another $300. He wasn't happy about that. So I took a look.
Why is the timing so low? OK, let'* get started here, unplug the MAF and lets do a VE tune.
Holy cow, that needs some work.
After adjusting the VE table the first thing he said is, wow, it'* running better already.
So I adjust the VE table and then check the MAF table. It seems kind of good but rather lean on the WOT area.
So I pull up the PE table, odd, why is everything at zero? And why is the commanded AFR at 14.1:1? That'* not right at all. So I grab my tables and copy them over to his and add 4* of timing. Then go out again.
Wow, the timing looks much better, the AFR is much better. The car pulls like crazy, no KR. He'* really happy now.
He said the guy that tuned his car last time was canned because he messed up a few cars. Looks like that guy was a real clown. He zeroed out several tables and never put them back. A over site like that could have wrecked a engine. It'* a good thing he watches his car so close. He knew something was wrong right away and didn't get on it to hard. All in all, a good time tuning.
Why is the timing so low? OK, let'* get started here, unplug the MAF and lets do a VE tune.
Holy cow, that needs some work.
After adjusting the VE table the first thing he said is, wow, it'* running better already.
So I adjust the VE table and then check the MAF table. It seems kind of good but rather lean on the WOT area.
So I pull up the PE table, odd, why is everything at zero? And why is the commanded AFR at 14.1:1? That'* not right at all. So I grab my tables and copy them over to his and add 4* of timing. Then go out again.
Wow, the timing looks much better, the AFR is much better. The car pulls like crazy, no KR. He'* really happy now.
He said the guy that tuned his car last time was canned because he messed up a few cars. Looks like that guy was a real clown. He zeroed out several tables and never put them back. A over site like that could have wrecked a engine. It'* a good thing he watches his car so close. He knew something was wrong right away and didn't get on it to hard. All in all, a good time tuning.
#2
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Nice job Dan. I cant believe he paid $700 for someone to garbage his setting that way. Shows that having a Tuner doesnt make you a tuner. Hehehe. It'* amazing what you need, and need to know to get things right in todays engines. When I was a kid, it took a timing light, vacuum gauge, allen wrench, and a slotted screwdriver.
#3
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Tell me about it. I still have a distributer wrench in my tool box. For timing you turned the distributer adjusted the dwell and gap, for mixture you turned a needle valve or two, perhaps change the jets. That was about it. Old school was easy. Now you can adjust one cell covering a small RPM range, and do something different if the throttle is doing one thing or another, and also a different thing if the engine temp is different. Each table works off another. Set the VE table, then the MAF curve, then the PE table. Then you can adjust timing. My head hurts just thinking about it.
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He stopped over again today and we changed his serpentine belt, now that was fun. Why is it a 5 minute job always takes over a hour. Later on Chris came back with Dave. We talked, oggled, and talked some more.
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