SpeedPRO Bottom End/Idle Tweaking

[dhegge]

Okay gus I have finally got my speedpro installed and operational... this thing is way cool. It was very easy to install since I had one of the fasttrackperformance interfaces?

I do have a couple of questions that I hope someone can help me with.

1. The car starts much harder than the old GM ECM... e.g. you have to crank it for a few 3-5 seconds to get it to start. Where as the old GM ECM used to start with just a bump of the key. Is this normal or do I need to tweak some parameters? Also once it does start the car starts to run fine, and then sounds like it is going to die, catches itself and then hunts for a few seconds and then runs fine. All of this with no throttle. I had to set the VE cells up to about 75 to get the car to stay idling. What am I missing?

2. Where should the RPM settings for the Open/Closed loop be?

3. Lance or Craig this one is for you! The 93 LT1 Corvette that I put the speedpro in has two fans a primay and secondary. Will the SpeedPRO sink enough current to drive both relays in parallel? I have it hooked up that way and it seems to be working fine, but I wanted to make sure. Otherwise I can add a third relay, but I really don't want to do that unless I have to.

4. The car does not seem to have near as much torque on the bottom end below 2000RPM. e.g. with the old computer it used to tear up the tires good. The new one barely chirps them when under a WOT takeoff. It pulls hard, damn hard in the mid range but seems to be a little light on the bottom end. I am thinking too much fuel?

Thanks,
Doug

 

[GPZ406]

I am having the exact same starting issues!!! Please help!!!

 

[UR50SLO]

Try this...

We had the same problem.

Try going under Idle parameters: IAC vs Coolant Temp

From what I remember it's a 2d screen and it should show you where your IAC is with the key on with one a line all the way up the screen. We set our IAC starting point **High number on vertical scale** very high.. that number is where the IAC will start at what ever coolant temp the engine is at. If you set that number high.. it will start up quickly and then work it's way down to where you have your base Idle set. This setting mainly helps with start-ups... Hope this helps guys. ~Scott.

Ps.. ours would not originaly start with out a good tap on the gas pedal~

 

[dhegge]

That Helped

Okay now that I cranked my IAC settings way up as you suggested... near 200 across the board the car now starts and idles smoothly. It still takes a good 2-3 seconds of cranking before it comes to life Is this normal? Best of all it no longer tries to die or hunt. It just idles nice and smooth

It seems like the high vertical number is way out of parameter, perhaps there is something else wrong that this is masking... Lance/Craig/Others?

Thanks for the Tip!
Doug

 

[dhegge]

RTFM

Okay after reading the Windows Documentation I found my problem. I had to add more fuel (ms) to the cranking table. Now the car starts like a dream, idles smooth, and goes like hell I have so much to learn, but so far I absolutely love my new SpeedPRO thanks Lance and Craig for making such a great product!

Doug

 

[HighPSI]

If your starting IAC #'s are in the 200 range, what is the IAC# when the car is warmed up and idling in neutral? If it is still high, open the throttle screw a litle more, then reset the idle parameters. Once I have the idling IAC #'s close to the botom (less than 20), I usually reset the TPS and try and get it to 13. I chose this# because of the resolution of the bottom scale on the throttle follower screen.

 

[dhegge]

TPS and IAC

Okay I will try that... FYI my TPS is 12 with no throttle and only 73 with full throttle/WOT. Should the TPS be higher. I saw a post somewhere that indicated that this should be atleast 80?

Doug

 

[HighPSI]

12 is fine for the idle TPS. You need to have over 80 TPS for the "clear flood mode" to work.

 

[dhegge]

80 TPS/Clear Flood

Okay how do I set the TPS on an LT1 motor? The old GM ECM used to say that it was 93% at WOT, but the SpeedPRO now says we are at 73% does that make any sense?

Clear flood... So if I understand what you are saying if you flood the motor you can hold the pedal on the floor and the engine will crank, but the injectors won't fire is that correct?

This would explain why I have flooded the motor a few times will playing with Cranking/Feul and not been able to get it to start without waiting a bit... I hate that!

Thanks,
Doug

 

[HighPSI]

I am not sure if this is possible, but you might want to get a TPS off of an L98 motor. The bolt holes are slotted on them. Although, it probably isn't worth the hassle (how often do you flood the motor?).

Your understanding of the "clear flood" mode is correct.