Ok so i have a 98 car. I current just did a lq4 swap stock bottem end, 233/239 113lsa cam and cnc'd l92 heads, and 2010 ls3 intake manifold rails and 42 lb injectors, and ls3map sensor wired into the factory harness colors to colors. Ok so the car is hard to make idle when cold to start off with idles fine once it warms up problem 1. problem 2 is that when you try and get into the throttle the car goes lean so was thinking fuel problem so we demanded 10.5 air fuel ratio and still went 17 lean. So then we have a gauge on the rail has 60lb at idle and no less than 55 if that when your getting into it. What could be the problem with this ! ! ! !

 

and it has a walbors 255 in it already as well.

 

injectors intake and rails are off a 2010 camaro 42lb injectors. only thing electric changed on car is was the map sensor cut stock one off wired in pig tail ls3 , same colors orange orage, grey grey, green to green. And then also injector adaptors that plugged and played from ls3 injectors to fit ls1 harness. Thats the only thing.

 

The idle problem is probably just cause it needs tuning with that cam... Do you have a base tune in it that takes into account the injector size and the cam?

Are you logging it when this is happening? First thing I would suspect is the MAP sensor - not sure that just wiring it up color to color is gonna work. The sensor could be different in operation (different scaler needed). You need to see what kind of MAP readings you are getting when this is happening.

 

Look at the scanner, if the MAP is reading about 98-100 kPa with the key one engine off, that should be OK. If you are trying to run this on the stock 98 tune it is not going to happen. It sounds like you have a wideband, just start tuning it. You will hurt the engine if you screw around too much. Do not do WOT runs on a untuned engine.

 

Ok I have heard ls3 map won't work with a 98 pcm. But I have ready about the conversions and that's why I did it. At idle its hard on cold startup runs fine when hot. And you can richen up the car at idle and that works but if you try to richen up the car when you on the gas it won't add. We demanded 10.5 airfuel and still went 17 lean. So does anyone else think it could be the map sensor with the 98 pcm ??? What should I look for there. Its a 1.5 bar 98 is 2 bar not sure of the difference.

 

Have datalogged it and said it needed 50 perect more fuel added. Asking for that much.

 

Did you change the MAP scaler & offset?

 

No I was told that it wouldn't wor'k that way. What does the map scale and offset need to be set at for a ls3 map to a ls1 harness

 

Map is reading 80 83 kpa with key on

 

There's your problem! You need to change the scaler and offset till it is 101 kpa with the key on.

Try changing the scaler from 94.4336 to 128.125 and change the offset from 10 to -0.31 (those are the values in an LS3 stock tune) see if that gets you close. Adjust by small amounts till it is 101 kpa.

Then retune it...

 

thanks alot ! !! will try that !

 

Copy the LS3 settings
101 kPa is @ sea level,
you set the scaler and offset for the sensor itself not to get the reading you want.

 

ok and where would i find that just search on hpt and get a tune someone has from a ls3 and look at the map stuff?

 

The numbers I gave you above are for an LS3.

 

Ok will in fact try it and let you know what I find out as soon as I get home

 

Sent you and the tuner PM's - I think the problem is HPtuners doesn't have those tables available for you. I checked several 98 tunes that I have on file with EFILive and I can see tables C6301 (scaler) and C6302 (offset)...

I recommend you find someone with EFILive near you to hook you up...

One more thing on my list of why I use EFILive instead of HPtuners...