cam tuning question

[Black'Rado]

Ok so i just got my TSP 220/220 .581/.581 112 LSA cam in my truck and i had my tune updated by my tuner and im doing some fine tunning myselft.

my question is, if i put in gear and let off the brake it will slowly accelerate till ~1200 rpm and 20mph. What is causing this? my idle is set to 650rpm.

Also if im cruising along at like 30mph and i let off the gas, its like on cruise and it will stay at a constant speed for awhile before it starts deceleration very slowly.

I have searched and i think it may be the desired airflow is too high, but im not 100% sure.

Thanks

[txchevy]

If Idle airflow is to high you will get this,and also look at your throttle cracker!!

[1meangto]

Throttle cracker is most likely the culprit but ve can effect this also. But it would have to be wayyyy off.

[Black'Rado]

its probly the throttle cracker, ill have to check that out.

should i just decrease the table by a few percent?

[5.7ute]

Desired airflow in gear sounds like it is too high from the symptom you first describe as well as TC.

[1meangto]

Yes start with that. Desired airflow may also be too high as ute said. I forget about that table sometimes.

Just bring it down by a small %. Or attach your file and someone can take a look to see where it's at and possibly help you out.

[Black'Rado]

i decreased the desired airflow a tad bit. it seemed to help a faint bit.

here is my tune file.

[SOMhaveit]

your throttle cracker air flow is very high. Might want to find the oem values and try them.

[Black'Rado]

i have my previous tune before the cracker was adjusted....ill try putting those values in place of my current ones and see if that helps.

thanks

[Black'Rado]

well i looked at my tune before cam and after and the throttle cracker values are the same.

the throttle follower has been changed though.

[swingtan]

To tell if "min idle air flow" is too high, watch your commanded spark at idle.

Firstly, check B5932 to see what is the base commanded spark. In your tune it's 16'.

Next, note the settings in B5935 and B5936. These tell you how much the PCM will try and correct the engine speed when idling. Your settings are fairly agressive....

So, when looking at the actual commended spark while logging the idle, you "should" see 16' of timing with timing corrections going up and down. If you highlight a section, it should average 16'. If you have too much min idle air ( B4307 ) then the average will be well under 16', too little idle air will have an average over 16'. Your current setting of >10gm/Sec is high and I'd probably drop it to around 8gm/Sec at running temps.

Your cracker also looks a bit high. You might like to try selecting the first 3 rows and 5 columns as a block and reduce the values by 50% to see how that goes.

Try this and see if it does any good.....

Simon.

[Black'Rado]

Ill flash that in the mornin and log on the way to work.

Thanks for all the help

[SOMhaveit]

well i looked at my tune before cam and after and the throttle cracker values are the same.

the throttle follower has been changed though.

I wonder if the Cracker values for a truck are so much different because the spark tables are so different from the cars?

[Black'Rado]

well i flashed that tune in and it doesnt have the cruise effect anymore but it now takes 3 tries of cranking before it fires up.

[swingtan]

When you say 3 tries, does it fire then die, or not even fire?

[Black'Rado]

no fire on the first 2 and then the 3rd it will fire up

[swingtan]

Log the starting process and post the log. It might be just the cranking VE.

[Black'Rado]

ill do that in the morning.

thanks for the help

[Black'Rado]

ok here is my log on a colt start all the way till operating temp

[swingtan]

a couple of things....


it's not uncommon to need a longer cranking time than for a stock engine. It looks like you cranked for about 1.5 to 2 seconds on the first 2 goes. This may not be quite long enough as the cam overlap will drop the engine efficiency at very low RPM. so you might find that just cranking it for a little longer may help.
If the above is no good, then try the attached tune. I've added a small amount of initial prime fuel, but also dropped the efficiency of the cranking VE table to allow for the new overlap. This should ( in theory ) keep the overall fueling about the same, but let the PCM think there is less intake air entering the motor.
I've also bumped commanded idle air up in the lower ECT range. This should also help a little.


If none of this helps, try a few experiments, one at a time, when starting...

does giving it a little bit of throttle when cranking help?
does priming the fuel system a few times help ? Just key on to where the dash lights come up, wait a few seconds then key off. Do this 3 or 4 times then try cranking.
Test the start at different temps by starting the car at different times of the day. From the log, it was 30'C at 13:45. try starting it early in the m,orning when it's cooler to see if the problem is better or worse.


Simon.

[Black'Rado]

thanks for all the help.

i have a walbro 255 fuel pump and it takes a bit more priming before startup. before it would take two cycles to prime up so bumping up the prime could help that

usually when its a hot start it takes the same time to crank as a cold start sometimes it takes more.

ill load the revised tune in and see if that works and report back

thanks

[swingtan]

It might also be worth logging a Wideband on the startup then. It might be that the fuel pressure is not quite right the first couple of goes and the fueling is messed up.

Simon

[Black'Rado]

yea i need to get a usb to serial adapter to program my lc1 output to read wideband voltage, its default as narowband

[Black'Rado]

well if i cycle my key 3-4 times it starts up on the first or second try.......

now another issue i have is at WOT im at 13.3 AFR and during cruising i see anywere from 12.7-15.5 averaging in the 13.8 range.

i really need to set up my lc1 so i can log on efi live.

[swingtan]

OK, if you do the key cycle a few times, you should get a bit more "prime" fuel dumped in the manifold. So it sounds like it's a tad lean on cold start. that shouldn't be too hard to fix up.

As for the rest of the mixtures... You need to get that WB set up and do some VE and MAF tuning. That should fix up most of that stuff. In your original log, it looked like LTFT's were on, so I'm guessing that you still have the O2 sensors enabled. These will cycle the mixtures from lean to rich and back to lean again, back and forth. This is the normal operation and is nothing to get too alarmed about. When in Closed Loop mode ( O2's enabled ), you can check the fuel trims ( STFT's and LTFT's ) to get an idea of how the engine is running. Don;t go by the WB sensor in this case.

Simon

[Black'Rado]

OK, if you do the key cycle a few times, you should get a bit more "prime" fuel dumped in the manifold. So it sounds like it's a tad lean on cold start. that shouldn't be too hard to fix up.
The revised tune should fix this

As for the rest of the mixtures... You need to get that WB set up and do some VE and MAF tuning. That should fix up most of that stuff. In your original log, it looked like LTFT's were on, so I'm guessing that you still have the O2 sensors enabled. These will cycle the mixtures from lean to rich and back to lean again, back and forth. This is the normal operation and is nothing to get too alarmed about. When in Closed Loop mode ( O2's enabled ), you can check the fuel trims ( STFT's and LTFT's ) to get an idea of how the engine is running. Don;t go by the WB sensor in this case.

Simon

Im going to order the serial to usb adaptor tonight so i can set that up

[swingtan]

RE: Revised tune.... possibly. It may need a bit more fuel but you'll soon know if you try it.

RE: WB, you can always connect up via the analogue interface. You may have an earth offset issue, but if you leave the WB sensor on the bench over night, then hook it all up and test the WB reading on the V2 before installing it in the exhaust, you may be able to see any offset errors. It should read 25:1 in free air.

[Black'Rado]

i have the WB already installed in my exhaust and the analog out 2 wire from the lc1 run so i can connect it to my V1.

I just need to configure the LC1 to read the correct voltages on output 2 for efi live.

[swingtan]

sounds like you have it worked out. I think there may be some info on here about setting up the LC1. I don't have one so can't help there.

[Black'Rado]

yea i have read several tutorials on it.

since i have v1 i belive i just need to set up the pid for scanning and external wb and then change the output voltages on my lc1

im thinking about getting the greg banish dvd, any experience with it?

[swingtan]

Nope, I'm a "self taught tuner"...... Most of training has been on this forum, previous experience, talking to other tuners and long, long nights of trial and error.

[5.7ute]

Black'Rado, what operating system are you using? (Dont have Efilive on this computer to see)
There is a setting in the .bin files for the key on fuel pump prime. If your fuel pump is run from the PCM (I know the Aussie Os's dont) we may be able to give you a .cax file so you can increase the prime time.

[swingtan]

He's running OS:12208322

[5.7ute]

Thanks Simon, i will have a look tonight & see what I can find.

[Black'Rado]

i have table B3201-Initial Fuel Prime

is that the one your talking about?

[5.7ute]

i have table B3201-Initial Fuel Prime

is that the one your talking about?

No. B3201 is an injector prime pulse. I am talking about the actual fuel pump prime time.(the time in seconds that the fuel pump runs when keyed on)

[swingtan]

Have we found out what happens if the engine cranks for longer than 2 sec? I'd like to see if it fires if it cranks for longer to see if it's the fuel pump priming or if it's just am initial cranking issue.

[Black'Rado]

yes i tried just cranking longer and it takes 2 tries
the first try for 3 sec
and the second cranks in about 1-2 sec

[swingtan]

But what if you crank it once for 5 to 10 seconds ?

[Black'Rado]

i just tried and it started in about 5 seconds on a cold start

on a warm start it took 2 tries

[swingtan]

Try this one. It's got additional fuel commanded when cranking. It may work, it may not :P

Simon.

[5.7ute]

Here is the .cax file for the fuel pump prime time. As I said before I do not know if it is active in your OS. If when raised it does not increase the time the fuel pump runs before startin return back to the stock setting.

[Black'Rado]

my tuner sent me a tune to try and it is working good now....thanks for all the help guys.

i just need to get my exhaust leak fixed so my wideband reads correct and then start logging with it.

[SOMhaveit]

Well, post it up so this issue sees some resolution and the next person finds a starting point for the cure, or this will just be one more dead end thread/search for the next guy having the same problem you were having.

[WeathermanShawn]

my tuner sent me a tune to try and it is working good now....thanks for all the help guys.

i just need to get my exhaust leak fixed so my wideband reads correct and then start logging with it.

What did he do?

I agree with Somehaveit. Not only did a lot of people attempt to assist you in your problem, but it could really help the next reader.

It will also help the next time your 'tuner' can't help you out..:grin:..

[joecar]

+1 x2

[Black'Rado]

8389

he modified the cranking VE, Desired airflow, and startup friction airflow correction

[Black'Rado]

Check out these logs i got at the track.....
It totally sucked and i ran slower than before the cam. But on the street it tells a different story, it pulls hard on the street.

first two logs(track1 and natrack2) are on motor, it was extremely heat soaked so i belive thats one reason it didnt run like it should.
3rd log(nitrous) is on nitrous, 75 wet shot on window switch 3000rpm-6400. It fell on its face as soon as it sprayed.
4th log(streetlaunch) is, first wot from dead stop on motor second wot from dead stop on nitrous. It sprayed fine and pulled great.

So im thinking heat soak was the issue. what do yall think?

[WeathermanShawn]

BlackRado:

Yea, thats some very high IAT's.

See you have a DTC for 'Engine Misfire'. Did not check your entire log to see where it was it. But, worth investigating.

I see you do have some +LTrims at WOT. Did you log AFR's, or did I just miss it? Perhaps leaning it up might help on those times.

Any case, was it really that hot (55C) or did you heat soak that bad..

[Black'Rado]

i belive the missfire is coming from low rpms while idling because of my cam

I have not got my LC1 set up to log AFR yet.

Ambient temps were around 95F. and it heatsoaks bad in the staging lanes

[joecar]

95-97 % injdc and no wideband in the NA logs... that is scary... do you know what is happening when you spray...?

Do you have a wet or dry kit...?

The high IAT means you have to do something to get cold air.

[WeathermanShawn]

OP, that cam may have just pushed you to the limits of your Fuel Injector Duty. If you start getting fuel starvation at upper RPM's, not only will you lose power..but scary things can happen to your motor.

When you run it the next time with your wideband (non-nitrous) and can get rid of the positive Trims, and dial in a good AFR..you might squeeze another 5% of out of your injectors.

Otherwise, may be time to upgrade..

[Black'Rado]

im running a wet shot.

i have my afr gauge and i was watching it to make sure i wasnt lean, i just havnt got it set to log yet.

[5.7ute]

I dont believe the problem lies purely with the IAT's. Some silly questions.
Was your bottle on with good pressure?
Why is your nitrous timing higher than N/A?
Do you run a fuel pressure safety switch that may have kept the gas from spraying?
Are you spraying pre or post maf?

Those will do for starters.

[Black'Rado]

I dont believe the problem lies purely with the IAT's. Some silly questions.
Was your bottle on with good pressure?
Why is your nitrous timing higher than N/A?
Do you run a fuel pressure safety switch that may have kept the gas from spraying?
Are you spraying pre or post maf?

Those will do for starters.

yep full bottle at 900psi with an automatic bottle heater

Not sure on timing, it was sprayed on the same tune as motor runs. That is odd?

No fuel pressure safety switch

It sprays after the maf, its a plate between the throttle body and intake mani.

[5.7ute]

Without wideband data it is all just a guess. But it looks like when you hit 2900 rpm the motor really fell on its face, like there was no nitrous, just fuel or a major misfire. I also notice a tps sensor code that needs looking at.
You really need to get some timing out on the spray. Increased airmass in the cylinder wants less timing or cylinder pressures will get too high. I use COS5 in mafless mode for this but there are many methods around that can work just as well.

[Black'Rado]

yea the TPS code really is weird, i cleared the code and it has not came back on yet.

i dont understand why it sprays fine from a roll and a launch on the street?

im working on getting my LC1 set up to log AFR

oh also i read somewere that rotating your maf has an effect on its readings? i installed a UPD cold air intake and had to turn the maf about 90 degrees to clear the hood. could that cause a problem?

thanks

[5.7ute]

Once you dialled the maf in with it rolled it shouldnt be the problem, even though it may not be perfect. Are you using a microswitch or TPS voltage to activate the window switch? Was there more than one nitrous run on the track where it didnt activate? If so do you have a log of that as well?

[Black'Rado]

i havnt done any maf tuning since installing the cold air

im using tps voltage to activate the window switch....i taped the wire at the pcm

yea there was another run that it did the same thing on nitrous but for some reason my log didnt save

[5.7ute]

There is a start for you. First get the wideband logging & get the maf dialled in with the cold air fitted.
Then remove some timing before spraying again. 2 - 3 degrees for the 75 shot.
Log TPS voltage to see if there is an issue. Also recheck your wiring connections. I reckon that the tps voltage has caused the nitrous not to activate in that log, but over the internet it is extremely hard to diagnose without the necessary data.

[Black'Rado]

Ok ill get that wideband going.

If the tps voltage didnt activate the nitrous then the fuel noid shouldnt have activated either causing it to bog like it did, correct?

ill log the tps voltage tonight and see whats up with it.

[5.7ute]

You would think so. I am more thinking more of a reduced power mode being tripped with the TPS fault.(assuming you are ETC)

[Black'Rado]

its drive by cable

i logged tps voltage on the attached logs earlier.

first one is after a cold start and short trip in town
the second one is a ride down the highway.....the funny tps is because it broke loose at 60

i cleared the codes before the ride and it never threw another code????