Hot start fix for the EVOX's.
 

Hey guys,

I don't know if somewhere in the forums this has been covered or not. I don't spend much time reading/looking around in the tuning section unless I post a specific question.

I've got a few EVOX's out there that have a difficult time starting once they are hot.

Example, car starts great cold, you drive it, get it to full temps. Then you stop somewhere and when you come back out to restart you have a LONG crank time to get the car to fire. That is the situation I am talking about.

I finally have my car sorted out so it doesn't have this problem.

I am running ID1000's in my car. The other few cars I've seen this on are running DW1000's or the ID1000's.

So, open your ROM, open the "Fuel OTher" tables. Then open "Cranking Enrichment IPW Adder (Main).

The stock table in my ROM looked like this:

-32/57
-18/40.2
-8/20.5
7/12
20/8.4
34/6
50/4.2
77/2.4
82/2.4

The new settings that have made the car start every single time when it is warm are like this:

-32/57
-18/40.2
-8/20.5
7/12
20/8
34/4
50/0
77/0
82/0

I hope this helps someone else out.

Badass! Thank you david!

Interesting Dave.

I'm in the Southeast with 105º days and I don't see this problem with FIC 1100's. I have also not touched that table.

Could there be another cause to this issue?

My car does this stock. It has since a few weeks after I bought it brand new. It's probably only happened 8 or 10 times and seems completely random about when it happens. I'll have to try these changes. Thanks!

i will post mine up later on ... figured this out abt 4 mths back ;) cos where i'm at is pretty hot even without running the car yet.

thx for sharing david and will ttys pretty soon;)

I believe the real issue is a mechanical one. Those injectors you listed can slowly leak as the car sits off. Then when you go to start it, there is too much fuel in the engine already.

This does fix that issue.

The FIC1100's don't have this warm start issues at all. If you read MrFred's post on the 1100's, you will see the issues he has had in the past with other brand injectors.


This is a good fix for it. :)
BTW: Do you think there will be any issues with cold starts when it is really cold out. (I live in NE and it get pretty fricken cold here.)

To some degree this has been addressed but not regarding pump gas, it was involving using E-85 and needing to adjust the IPW to get it starting like it was supposed to regardless of hot or cold temperatures. Tephra I think posted something a few months back on what needed to be changed when the IPW table was included.

For reference, FIC and ID's are both made by Bosch, so don't tell me FIC's don't have the issue and ID's do.

My car cold starts PERFECTLY 100% of the time. The only issue I've seen is with hot, restarts after the car has sit for over a few minutes.

I am just sharing what I found, my car has not had any trouble starting since the change was made and I hoped it would help someone else.

I don't really like posting tuning tips and such but figured I owed something. Use the tip I supplied or don't, I was just trying to be helpful.

BTW, all these cars are on pump gas, not E85.

Also, in reference to ID injectors. It is 100% my choice of injector in every build we do. NO other engine management, nor the EVO8-9's have this same problem. It is NOT the injector.

Yea same idea for cold starts with E85, but the opposite.

This is not necessarily new news, however it's good news to re-appear every so often.

The IPW adder is for a stock car with stock injectors so it makes sense that it needs to be tweaked when different injectors go in the car

- Bryan

The formula to figure out how much you need to change... this is for regular fuel (93/91)

New Cranking primer IPW = old IPW x [ old injector scale / new injector scale]

for E85...

Although I am not 100% sure...

Is figure out the forumla same as above, since most likely you tuned latency and scaling on regular fuel then switched to E85. Then once those values are figured out... multiple the entire table by 0.3-0.35 or 35-35%. To have new numbers...

Hmm i have hard starts when I am cold. Starts fine when hot.

Then try increasing the IPW at colder temps, see if it helps.

If not, try the other way. ;)

- Bryan

Started to happen right after JNZ pump upgrade and injector install so filters may be dirty or leaky injectors? As for changing stuff I have an 2009 so kind of in a wasteland of no useable methods of getting a tune other than OTS maps.

Sorry for the derail.

Possible improper injector tune. If you post your scaling, latency and current fuel trims we can help.

- Bryan

Nice work Dave, I'll have to file this into my tuning book of tricks just in case. :)