Pretty new at this still and I can't track this down quite yet. It's about 30F right now and I can't get the car to start. If I give it just a tiny spray of starting fluid it'll fire right up. Playing with the base timing seems to help also. It will restart fine if it's run only a few seconds or more. I'm not sure if I need to be adjusting the IAC settings or if this is a fuel or spark issue. I'm using an $8D mask and engine specs are L98 with LT1 intake, 24# injectors, LT4 hot cam, shorty headers, and pro topline heads. Trans is T56.

 

Does it crank for ~30 seconds or so and then fire off or it won't ever start when cold without starting fluid?

Reason I ask is when I had the FP relay go out it would crank and crank for a half minute or so and then fire off just fine because of the oil pressure switch and how it bypasses the relay after a bit.

 

It's not the FP relay. I can hear the pump running the whole time.

 

When did this problem start? You say playing with base timing or starting fluid helps. So does advancing the timing or retarding help?

 

I can't remember now which way I had to adjust the timing. I just started working on it again for the first time in about a year and I've just been using starting fluid to get it fired up. I'm reading that below 400rpm that the ignition module is controlling spark; What about fuel? Is that handled by the table or is there a default that's used below 400rpm also?

 

During cranking the distributor sparks the plugs at the base timing. No ECM control. With that cam and intake the base should be about 8 degrees BTDC. Set this with the engine up to temperature and also set this value in the calibration (they need to match).

In $8D, for fueling during crank there is a stable of PW tables and modifiers. There is also a base PW scalar value. I'd be tempted to just increase that value by 10%. And see how it works out.

Between the base timing and some additional fuel should start right up.

RBob.

 

Thanks, RBob! Base timing is 6 degrees right now, I'll bump it to 8. Where can I adjust the PW scalar in TunerPro RT? I found in another of your posts that it's at L83AD: FDB 13108 ; SCALAR FOR MAX PW but I don't use an editor so I'm not sure where to find it. I've looked through the list of scalars in the program but haven't found it. After some late night reading last night, I figured I need to raise the crank PW vs temp values and then possibly pulse mult. vs ref pulses and fuel delivery delay vs MAT.

 

Well, that was easy. I tried the AUJP crank PW vs. temp table and the car tried to start but didn't quite make it. So, I raised the values 15% at 8 deg C and colder and it fired right up. The high idle dropped off rather quick, though, and it feels sort of like it's choked too much for about a minute before smoothing out. I'll take a video next time I start it from cold. It's about 65F here now, by the way.

 

Just as an FYI Adding to the 8* and below probably did very little. Since 65F ambient would hit more in the 20* value. In my own case I had to increase the values to about the 56* box to get things smoothed. Of course like anything in DIY prom it's trial and error.

 

Yep, you're right. It must have been cooler in the garage than outside so the change at 8deg had an effect. Today it was even warmer, about 70deg, and I had to adjust the 20C value for more fuel for it to start. Here's the video from dead cold when it started:
http://www.youtube.com/watch?v=3ar03le3UuM
You can hear a bit of a surge at about the minute mark and it smells pretty rich so I think I need to lean it out there a bit.

 

Here's another video (from outside) where it's easier to hear the surging. Someone told me I might need to adjust the Loop Open % Change AFR Vs. MAP and the Loop Open AFR % Change Vs. Coolant. Is changing this a good place to start or should I be changing the VE table around idle?
http://www.youtube.com/watch?v=gHgVgwGM0FY