Hi,

I just want to know if anybody had any problem with a map sensor because of a racing cam with a tpi because I have only 3 psi of vaccum (idle) and my engine is running way too rich so I would like to know if you would have a solution about that problem!?!?!??

Thanks

Steph

 

dont know what ecm you are using but i use a EBL Flash and they have a parameter for N alpha which bases fuel more on speed and tps then MAP.... so you might want to look into if your ecm has that ability also....

 

How do I know all that because I know that the computer is a 92 camaro with a 5.7 and I do have a custom chip made!!! But it is so rich that it's my third set of spark plug that I've use without pulling the vehicule out of the garage!!!

Thanks

Steph

 

Idle at around 80kPA? Fun isnt it? at that kPA the ECM thinks you have the throttle almost to the floor.................

You need to tune your spark table (raise the SA) and VE (lower it) to match it , also increase idle speed and remove "idle vs rpm tables" would help. You also may have to change the O2 mV settings to get the idle stable, you will need a WBO2 to tune it correctly.

Read this

https://www.thirdgen.org/forums/diy-...light=big+idle

/N.

 

Thanks for all those infos!!! The only thing that I would try for now is an adjustable map!!!

We will see!!!

Thanks

Steph

 

an "adjustable map" would be lying to the ECM, you could be headed for trouble doing that. if you set it so at 80 kpa at idle the motor is getting the right amount of fuel, but when you have some RPM built & its at 80 kpa it will be too lean.
the way to do it is by tuning the chip for the correct amount of fuel at idle.
with a big cam, it really needs to idle in open loop too.

you said its a 92 5.7, so i take it its TPI.
JP86SS & a few others put together S_AUJP_V4 that is for the TPI speed density systems that were used from 90~92 on the TPI motors. it has the ability to idle in open loop.

 

Thanks for your precious help! You are amazing guys!!!

My 383 TPI (speed density from a 92 Z-28). Have some 11.1 pistons, a crane blue racer cam and some 210 cc cylinder heads with 64cc chamber. The chip as been reprogrammed by FASTCHIP!



P.S. I found this yesterday on ebay: http://cgi.ebay.ca/ws/eBayISAPI.dll?...m=150244742346 looks pretty interesting!!!

Steph

 

I dont think any mailorder tune can get it to run right...... So take it to a shop that can tune TPI's correct or DIY (get a WBO2 and buy the chip burning stuff......)

/N.

 

Ok gta324 but I am new in there so I need to know what is a WB02 and where can I get that stuff???

Thanks

Steph

 

wide band 02 sensor I purchased here with a group buy from Innovate. Summit sells too along with others.

Craig Moates site will show you the tuning equiptment.

As stated you need to idle "open loop" with no feedback from stock NB 02 sensor. you basically command the A/F ratio (13.5/1?)