Finally got a scan tool, but.......

[fizzler]

Yep got my scan tool and love it! I was playing with the chip some tonight and saw a quick 10 degrees of retard "once" so I quit!Ha

Couple of things that I don't understand...

Why would the scan tool say 13 psi of boost and the auto meter gauge says 17 psi or so? Am I missing something?

Also I did a couple of dead stop pulls and right before it would shift into 2nd it would just quit pulling for just a milli second (like it had shut off) then pull again fine! The second time I did it I noticed my fuel pressure drop "way" off while it did this stumble! I didn't have very much gas in the tank, could this be the reason? Probably 1/8 of a tank! It doesn't do it if I stab the gas if I'm already moving a bit, only on a fairly hard launch!

Thanks for any help on this, I sure need it!

God bless

 

[MikeRenz]

do you have a 3 bar map sensor? if so you need to change your preferences to reflect that map sensor.

 

[sy112]

what scan tool? My turbolink is off just a little on boost.

could be gas in tank,or possibly hitting overboost or rev limiter. I believe both of those are fuel cutoffs. What was you boost/rpm's when this occured? But being as this happens only on boosted launches I'd say it's the "slosh effect". But then again it does it when shifting into second, which is real close to max boost and rpm before shift. I never really get on my truck if it's much below 1/2 a tank, better safe than sorry. Do you have a way to post the file? would like to see.

 

[fizzler]

The scan tool I have is a "OTC 4000E".

What settings do I need to change with the 3 bar MAP??? Don't understand!
BTW, I have an Ultimate chip.

I don't have a way to post the file, but the shut off occurs before shifting into 2nd. The more I think about it, I think it's slosh related! From the time I hit it, it has just enough time to use the fuel in the line then pressure drops to, ha, under 30psi as it dies for a second, then of course I get out of it! I'd say I had no more than 1/8 of a tank!!!!! Learning something every day about the Sy!

What do I need to change (preferences) to reflect my 3 bar MAP! Really got me there!

God bless,
James

 

[MikeRenz]

i was kinda hoping you just had datamaster. I've never heard of your scan tool....but i bet that is why your reading seems way off. Just like the stock boost gauge doesn't show your correct boost level anymore.

 

[InvisiBill]

That's just a generic GM scantool. I don't know if you can set it to read the 3-bar correctly. The scantool programs (DM and TL) have a setting where you can switch between stock 2-bar or 3-bar. The 89 Turbo Trans Am is what used the 3-bar stock. Can you set the scantool for that maybe? I don't know if that would screw up the rest of the data though...

In short, this isn't nearly as good as DM or TL.

As for cutting out, it's well known that these trucks have a problem with fuel slosh. You shouldn't be doing launches at less than 1/4 tank, 1/2 or so if you've lowered the rear of the truck to level it out.

 

[fizzler]

Hmmmm, I just bought this scan tool! Thought I was gettin a deal!haha

Question: how do I know if there is a 2 or 3 bar Map sensor in my tuuck???

Thanks for all the help, I really appreciate it!

God bless

 

[Flyin Ryan]

Here's a pic of my 3 bar map.. I guess you can blow the pic up and compare part #'s to the one you have.... . and don't do boosted launches with less then 1/2 tank of fuel... motor go pop!

 

[InvisiBill]

Question: how do I know if there is a 2 or 3 bar Map sensor in my tuuck???

What chip do you have? The chip has to be calibrated for the proper MAP sensor. If you have a stock or big-name aftermarket chip (ATR, KB, etc.) it's a 2-bar chip. If you have an Ultimate or a custom 3-bar chip (duh), it's a 3-bar chip.

Turn the key on, but don't start the truck. If the stock boost gauge shows 0, you've got a 2-bar sensor. If it shows negative something, it's a 3-bar. This is because the gauge is calibrated for the 2-bar sensor.

I believe the only difference in appearance of the MAP sensors is the color of the connector...

 

[fizzler]

Thanks guys and no more launching with under a half tank! (even though it wasn't hard launching)!

Thanks for the pic Boostedpimp, it helped!!!!!

 

[Flyin Ryan]

Thanks guys and no more launching with under a half tank! (even though it wasn't hard launching)!

Thanks for the pic Boostedpimp, it helped!!!!!

No prob.. do you have any pics of your cobra??