Running very rich

[thedugan]

Trying to figure out why its running soooo rich at idle. Oil has some gas in it which scares me, plugs are getting fouled way to fast, and im also sick of stinking like gas when I leave the shop. I have the regulator set at 45pounds and the DFI to match. Running a Wide band so I figured that it would adjust the air fuel for me. Not sure what im doing wrong.
Car idle's fine and runs smooth just running wayyy to rich
Accel DFI Gen7 setup. 55 pound injectors. Timing at 20 degrees at 2000.
Thanks. Doug

[ProdigyCustoms]

The wide band will only make up for 20% and you DO NOT want the correction at 20% all the time.

Have you set up your targets and adjusted you VE table yet?

[LSXfan]

try lowering the minimum pulse width for the injectors, if the rest of the tune is good

[Jim Nilsen]

Are you running sequential or batchfire?

[thedugan]

sequential. The good old DUAL SYnc.....

[Jim Nilsen]

sequential. The good old DUAL SYnc.....

What is your injector timing set at ?

[thedugan]

Jim I did not touch it so its factory.
If Im on the screen that you are thinking of all the values read 360.

[Jim Nilsen]

Jim I did not touch it so its factory.
If Im on the screen that you are thinking of all the values read 360.

The factory default may not be correct and may need to be set correctly. The injector timing is supossed to be set at 90 degrees before the intake valve opening at .050 which makes it start to fire the injector about the same time the piston is halfway down on the firing stroke. If I remember it right the default is 218 degrees which is way late by at least 70 degreees and could cause problems with some cams.

I am still learning and have gone thru a lot of versions and they are not all the same. Some do not have the same screens and prompts that others do. If you search long enough you will find it, just remember how you got there,lol.

There are so many of the same parameters in multiple screens that it gets confusing to start out. Depending how you tune it some things don't matter and will get worked out and somethings like the injector timing have to be right or nothing else will be able to mask it or change it.

I will try to find it so I can explain how to get there.

[Mike Norris]

Without looking at both the current tune and a data log it is very hard to say. Frank has hit a valid point and if you are constantly at a large negative correction it can be at the limit. This can happen even when all the base parameters are correct.

If you want to send me a log and current program I can take a look. Also please send me some good info as far as cam specs, throttle body, cubic inches and compression ratio.

Mike Norris

[thedugan]

Email sent

Thanks for the help Mike and Jim. Appreciate it

[Mike Norris]

Got it Doug and sent you some info back. let me know.

Mike Norris

[thedugan]

Well drove it today for the first time in 2 years. Car wants to go once I get the tune together. And it let me get some good data on the tune.

[thedugan]

What do you think my timing should be set at. I set it at 22 at 2000 RPM based on what Accel told me. Synced the DFI with the balancer. Seems like I should have more timing. Its a blower motor and I dont want to take to many chances so I want confirm if anyone thinks it needs more.

[ProdigyCustoms]

I know you sent the program to Mike, if you want to send it to me I will look it over also. Mike is on a tuning trip down here and is staying with us tonight, so we can compare notes and see what we can find.

Send whatever logs you have also.

[thedugan]

Email sent Frank. Thanks a bunch guys

[ProdigyCustoms]

DO NOT drive the car. Found it. The MAP is sclaed completly wrong, your running off the map. Got lots of work to do. Super lean as soon as you touch the gas.

[Mike Norris]

Hi Doug,

I talked to Frank a bit today and he said he had you on the phone. He said initally he had you going in what seemed to be the right direction and then it started going to heck. I believe you are checking for a vacuum leak now, whihc is good, but I have another idea for you.

It sounded like the hotter it got the leaner it got. What I think is going on is that your Base VE Correction Coef vs. Coolant Temp (BVEC vs. CT) table is not right. This also called Warmup Enrichment. In other words it is adding the improper amount of fuel as the coolant temp changes.

But before you go to make adjustments the BVEC vs. CT, you should get the car running properly at warm operating temps. By that I mean the Base VE tables can only be set at proper running temp of 170-180*F to 200*F or so with no Coolant Temp or Intake Air Temp correction.

Once the Base VE tables are set, then you can work on the Warmup Enrichment (BVEC vs. CT).

Looking at the original base tune you sent me, it is quite a slope. Not all engines are the same and some will need different slopes then others. Yours at the colder temps (-40*F) is adding as much as 41.8 percent fuel to the Base VE. At the normal cold temps (+40 to 50*F) she is adding about 32% to the Base VE table. From there is gradually slopes down to 0% correction at 190*F.

With that said I would say you may only need about 15-20% correection at the normal cold start temps (+40 to 50*F) and then gradually down to zero correction by 180*F.

Like I say, this is pretty much just a general idea, but hopefully this helps you out.

Mike Norris