Tuning my 3400/3500

[johnnymossville]

Well, I have had a chance to drive the Beretta a few times now. I will try to datalog this weekend and post it for input but I have a couple of issues right now.

1. It will not idle below about 1200 rpm without dying and I believe it is because it is to rich at idle. At idle the INT is like 131 and when I speed the engine up to 1500-2000 rpm it is 128. Does this make sense and what is the quickest way to get it to idle correctly?

2. After it has been running for a while and if it dies it is hard to restart. It sounds like it is flooded.What might this be and is their a quick fix?

I am getting the exh. on it Monday morning and then I'll be able to install the wideband o2 so that I will be able to get serious about tuning it, but it would be nice if I could get it to idle.
Thanks everybody, John.

[gp13069]

well i would start with simple stuff first like ,
idle relearn
check for leaks in the vacuum system gaskets , hoses , any type of vacuum tees your using.
you may need a vacuum pump to run the cam you have it may not make enough vacuum to run the all the goodies to tell the computer that you going to idle.
on the other hand it may be the egr system partly stuck open or not even working right. that may or may not trip a check engine light.
or you just forgot to hook something up. Ii have done this many times i get excited THAT SOMETHING I JUST WORKED ON IS GOING RUN. turn the key and either nothing happens or things break. ( that was when i was younger and in a hurry) i hope i have helped a little bit (:
good luck

[IsaacHayes]

I thought if the INT/BLM was higher than 128 it is adding fuel?

[Superdave]

I thought if the INT/BLM was higher than 128 it is adding fuel?

correct


Looks like it's lean at idle, which isn't always a bad thing when you have a large cam.


It sounds like you are going to need to adjust the cranking fuel pulsewidth, I'll check my settings tonight and let you know what they are...

[johnnymossville]

Thanks Dave, I'll be glad to get the wide band on there. I'll still try to get a datalog session on here so you can take a look at it. Hopefully I can get one up tomorrow.

[johnnymossville]

Wow, after further review it appears that I am running lean throughout the RPM range. Tonight I was getting readings from 131 to 148 on the INT and the BLM as I pulled the RPM up from 1250 to almost 4000. I keep getting an error box when I try to datalog, something about failed to start a log or something like that. I am going to try to figure out what the problem is as it won't let me type in the box to name the log. Earlier i was thinking that it was rich because becuase it was reading 131 and not that it was lean because it was asking for more fuel. Duh If you have any ideas I sure could use the help. Thanks

[johnnymossville]

I am having trouble datalogging. When I try to set up a datalog and click the "Select Log File For Rec/Play" it will not let me type in a name for a file and then it will not record becuase a file has not been created. How do I fix this?

[IsaacHayes]

Select a folder, hit open and then I think it prompts you to make a new one. Or something like that. It's deceiving.

[Superdave]

It should let you type in a random name for the .adl file.. don't type anything but "datalog1" and hit OK.. post up what happens..

if it accepts then hit the connect to ecm button... then the record button.

oh yah, make sure you have a valid .ads file selected in the menu as well.


*edit, NP on the tuning advice, glad it worked out.

[3400-95-Modified]

Its amazing what a car will do when you give it fuel too... I was running at 14.3:1 a/f at the dragstrip and still got a 14.8 at 95mph... LOL

[johnnymossville]

Yea, it works. Now I'll try to post them.

Datalog 3 has a roll and go from 8 mph to 76 mph. I actually cranked it like 6350 rpm when I had planned on shifting at 6000. I am curious what you think of of the INT, BLM, and the timing. For some reason I have the idle speed at 1000 rpm instead of 900 in drive, Duh. I'll have to change that tomorrow.


From what I see, it's lean at idle and rich everywhere else. It also has too much spark advance in my opinion. What do you think?

[Superdave]

ok, i finally got a chance to take a look... Pretty classic symptoms of the VE tables just needing to be dialed in. Looks like you've got some random knock but it's noting to be concerned about yet.. Once we get the VE dialed in most of that should go away, if it dosen't then we'll play with the spark advance table.


The first thing i'd do is open up the idle VE table, select all the values between 40 and 30 KPA / 800-1000 RPM, bring up the toolbox, make sure "Offset +/-" is selcted then add the number 2 to that section. That should get the idle back closer to 128, with a large cam alot of guys try to run the idle a little on the lean side, cam overlap causes weird things at low RPM's so the BLM's often read leaner than they really are.


Next, your part throttle cruse is all pretty rich everywhere.. open up the VE adder table and subtract 3 from 1200 RPM up to 3200 RPM for now.. then log it and see how she looks.


your PE fuel is a little lean but instead of throwing more fuel at it try decreasing the spark advance by 1.5 degrees between 90 and 100 Kpa, 3600 and 4800 RPM.

[johnnymossville]

Well, I modified the bin and put it in. It seemed to cruise better on the way to work but I didn't try to datalog until the ride home. That was a bad experience as it seems that my o2 sensor took a crap and the car didn't want to stay running unless it was in PE. When I got on the highway I passed a few slow cars and made it to 67 mph (55 mph speed limit),then it ran fine until I slowed down to turn into my subdivision. lol It ran like crap until I got into my drive and shut it off. Too much rain to change the o2 sensor so I'll try to get it done tomorrow. I'm sure the sensor is bad because it was reading over 1100 mv. and only crossed rich/lean one time while running for around twenty minutes. I'll post some logs after I change it and we'll see how the changes worked.

[johnnymossville]

Got the o2 sensor changed and updated the bin. today. I took it for a ride and did a few logs. Here they are after the changes.

Well, somehow these are all the same log of an idle log. LOL I'll try to upload the rest of them.

[johnnymossville]

Trying again. lol The first log is long and has idle, a hill, and a second gear pull. the other two are short because the computer locked up.