Rough idle with new tune

[Travis Koch]

 So I have Venom running and driving but there are a few things to sort out, one of which is the aforementioned rough idle.  I am going to do a bunch of searching right now but just in case this rings a bell with someone, I'll ask here first.

 Sounds like a miss but smooths out when RPM's are raised towards 1500-2000.
Injectors appear to function, as do plugs, cables, etc....
Boost leak checked and fixed all boost/vacuum leaks,...... I think..... (found a leaky fuel line while I was at it)
Coolant temp sensor works, TPS is adjusted, base idle is set and BISS has been set.

By the way.... my timing was off by a tooth but I reset the timing the other day and it is much better than it was at that point.

I noticed if I pinch the vacuum line going to the MAP ( I am on speed density by the way) the motor almost instantly smooths out but after a few seconds it doesn't want to run anymore, so I released the pinch and it goes back to idling rough...

It runs at about 10 inches hg.

Definitely needs some fine tuning done to the ECU.  this will be accomplished with Ostrich.  I am not sure if this roughness will be smoothed out with some proper tuning but so far everything seems to check out so hopefully that is all that it needs is a good tune.  I may put in new plugs and wires but the engine was running fine before the AEM shit the bed and I couldn't use it anymore.

So anyhow, off I go to use the Google machine...

[Vlad Busta]

Try adjusting your timing at idle.  It could help with your rough idle.  Also be sure to keep your afr around 15 while playing with your timing at idle.
by pinching the hose to your MAP you have the ECU thinking you're at 0psi and 1000rpm so it's using that VE and timing spec from the tables. 
I think you'll be able to smooth it out with timing.  Just be sure the car is heated up properly before playing with the VE tables.
Later, Vlad.

[Travis Koch]

Thanks Vlad, I'll try that.  I have swapped in a new black top CAS to see if that would help but there was no change there.  I will try the timing adjustments, and I still have to get the lean warm up situation under control.  From what I could see, my last round of adjustments didn't appear to make any difference to the lean idling.  Probably just need more practice. 

 I have the front end apart again to make some adjustments to the lower control arms but that's minor. 

Tomorrow night I should have a bit of time to make some ECU adjustments.  I am trying to make small adjustments right now and if there is no change I return them to the original setting, I don't want to change too many things and make it even harder to fix or simply forget what I did. 

 Sitting in a hot car on a hot day trying to think doesn't work so well.

By the way,  I noticed on my logger that the timing is bouncing around from 6 - 12 - 18 degrees.  IT doesn't want to stay steady.  Not sure what to expect but when I log my Laser the timing stays pretty f'n close to 16.

[Vlad Busta]

The reason why the timing might be jumping is that the boost readings might be changing if you're playing with the throttle. You could try and set your entire timing table to say 16 and go down 1 degree at a time from there. Also be sure that when you upload the new bin that it says successful. If not then reinitialize the ostrich and try the upload again.
By setting the entire timing table to 16 you don't have to worry what rpm or boost you're at.
Later, Vlad.

[Brett Haviland]

Went and helped trav out. Multiple tables were set up a bit off. Zero'ed out all the closed loop tables and got the VE tables setup to maintain a constant a/f ratio now. Wierd thing I noticed is at 14.5-15 a/f ratio, engine idles like it has nasty cams or the timing is off. At 13-14 a/f it idles like stock almost. Really wiierd.

[Vlad Busta]

Weird that the car likes it that rich.  Could be that you just need to play with the timing at idle.  Travis, what cams are in the car?

Later, Vlad.

[Travis Koch]

well, I thought they were stock but of course they will have to be measured to be sure.  I am going to install a set of 272's and spec these ones out to be sure what they are.

I have it idling a bit better but I want to be able to take it out for a good cruise, and until I swap the tranny that is not going to happen.

Another funny thing is that the car is quite hard to start after it is hot.  This seems like a recent change so I am going to go back and start with the original tune you gave me and see if there are any starting differences.  Brett mentioned that there may be a possible dirty injector, so I swapped injectors (w/660's) to test out the theory, with no change in starting behaviour.  I'm thinking it may have more to do with the coolant comp table here but we'll see.  I guess i'll pull the cams, swap the tranny, install new cams, maybe some adjustable cam gears.....

 No panic for any of that, lot's of work to do on other things for a bit...

[Ryan Singh]

I once had a bitch of a time getting mine to start once it got hot...like even just going to the 7/11 ten min from home. I'd turn it off and run in to grab something and come back to start it and nothing. Had to wait like half hour minimum at times...ended up being the coolant temp sensor.

[Vlad Busta]

The coolant temp table is probably where you want to start.  Remember that 3 means zero enrichment.  Anything above 3 and you're richening it up at that coolant point and anything less than 3 is leaning it out.  Start with 0.5 increments and see if leaning it out or richening it up helps.  If not then you may need to play with the 120 second start up table.

I too have this issue but am too lazy to play around with it    I find it easier to play with the throttle when warm but I think it's just because I'm too rich and just need to lean the table out.

Later, Vlad.

[Brett Haviland]

Yeah, I played wiith the coolant temp enrichment tables. Zero"ed out the 120 second table as well (all 3's) I was going to give trav my adjusted coolant temp tables from my white colt... but I had to head down to California for vacation before I could pull them. off my labtop. Adjustment of the coolant temp tables should help. I also played with the timing at idle ( increased by 5 deg increments, minimal change in the lumpy idle (once the a/f's were set back to 15 a/f) and also tried reducing the timing in. 5 deg increments, same thing. May just have cams, or regrinds, and trav just doesn't know it lol.

[Vlad Busta]

Yeah, I played wiith the coolant temp enrichment tables. Zero"ed out the 120 second table as well (all 3's) I was going to give trav my adjusted coolant temp tables from my white colt... but I had to head down to California for vacation before I could pull them. off my labtop. Adjustment of the coolant temp tables should help. I also played with the timing at idle ( increased by 5 deg increments, minimal change in the lumpy idle (once the a/f's were set back to 15 a/f) and also tried reducing the timing in. 5 deg increments, same thing. May just have cams, or regrinds, and trav just doesn't know it lol.

You might be right 

Travis, I have a set of Delta 272 in my car, I don't know if you remember the way my car idled when I stopped by that day but it is a little lumpy and pulls a -10 inhg of vacuum.  Like I said though, play with the 120 second table in 0.5 increments and see if it helps.

Later, Vlad.

[Travis Koch]

Getting closer..... Reset the tables for coolant comp and 120 sec. and made a few more adjustments before I fired up...... AAANNNDDDDDD..... Got a respectable 15.3, 15.1, fluctuation around this area upon start up.  I think I'll look into the tranny swap next before I carry on tuning anymore.......  We'll see.

Thanks for your help so far guys.

BTW,,,,,is the injector PW startup table only valid while cranking or is it constantly in effect?

[Vlad Busta]

Only on start up.