Dissapointment at the dyno - Page 4

Tyson Schmidt · 10-08-2007, 12:28 PM

Maybe someone already mentioned this but.....

Have you checked that you are getting full throttle opening?

JohnJL · 10-08-2007, 12:33 PM

If I could suggest triple-checking the ignition again. Lots of people, including me, chase "fuel issues" that are in reality or compounded by spark problems.

Can you turn down the resolution on the map?

Are you using someone's tested msq file?

Do you perhaps have a sensor issue...have you tested your TPS and checked it is sending proper signal and it is moving throughout its range? That it is not pre-loaded at idle? If you dont have a TPS you can try running that in AAlpha-n (i think?) mode and see if that works better than your MAP sensor.

Also check your MAP sensor. Can you switch in another?

Scott R · Scott R's Garage

Quote:

Originally Posted by JohnJL

If I could suggest triple-checking the ignition again. Lots of people, including me, chase "fuel issues" that are in reality or compounded by spark problems.

Can you turn down the resolution on the map?

Are you using someone's tested msq file?

Do you perhaps have a sensor issue...have you tested your TPS and checked it is sending proper signal and it is moving throughout its range? That it is not pre-loaded at idle? If you dont have a TPS you can try running that in AAlpha-n (i think?) mode and see if that works better than your MAP sensor.

Also check your MAP sensor. Can you switch in another?

This system does not use a TPS, which is why it has custom code. The MAP sensor is inside the MS unit itself, I'll have to look into how you test that, I'm sure there is a way.

As far as the ignition system is concerned, the distributor was rebuilt when the motor was done, the MSD 6 is about two months old, only real suspect could be the plug wires. The wires were new last summer when the engine went.

TimT · 10-08-2007, 02:55 PM

Hmmm how are you collecting the MAP signal?

FWIW trying to tune an engine based on MAP load is difficult.Transitions and tip in will be tough..

With any sort of lumpy cam you want TPS or a TPS/MAP blend..

I agree with the others inre making sure your ignition system is up to snuff.. check total advance at 6000 rpm (ok you can sneak a peak at 3500-4000)... just assure you have say 30 deg at 6000... you wont be using ignition advance to tune for power just yet... If you dont have that sort of total advance... check the distributor..

tune the ECU at steady states through out the load ranges.. don't worry about total power first...

first run through the rpm range and set fueling for all rpm ranges with no load

then drive the car on the dyno.. apply load, and correct the cels such that you have a nice a/f say 13:1

continue this iteration....

takes hours from scratch...

wastintime · 10-08-2007, 03:57 PM

I've never read a tuning plot quite like that, but wht AFRs were you actually running, to me it looks like it's running rich even for a turbo let alone an NA car

Scott R · Scott R's Garage

Quote:

Originally Posted by wastintime

I've never read a tuning plot quite like that, but wht AFRs were you actually running, to me it looks like it's running rich even for a turbo let alone an NA car

The tables are set for 14:7 accept the accel bins which are near 13:1, that's what the computer believes anyway. The LC1 and dyno AFR disagree, and when you lower the bins further, the MAP wanders, surging is worse, hesitation starts, and bucking on hard accel.

EDIT: forgot to add when I add "barometric compensation" things get richer, and even more unstable.

sjf911 · sjf911's Garage

Is it possible your cams are timed incorrectly?

Scott R · Scott R's Garage

Quote:

Originally Posted by sjf911

Is it possible your cams are timed incorrectly?

Anything is possible, however the guy that did the rebuild has been doing this for 30 or so years, used to work under Grady Clay in the 70's. They turn out a tremendous amount of engines each year from what I've see. I will most definitely put a z-block on and check it though.

911Mac · 10-08-2007, 06:37 PM

Scott,

Tony's kit comes with 30 lb injectors and the fuel pressure regulator is set to 2.5 bar. This combination makes the injectors flow 27.4lbs/hr. According to Tony that's good for up to 254 HP. Why did you feel like you had to switch to larger injectors? What fuel pressure are you running?
FWIW, getting my SC to idle without hunting required setting all the VE bins around where it idled to the same value.

You're a braver man than me if you're willing to reinstall the CIS. I understand Wayne's point, but What if it doesn't run correctly? The CIS is no less complex than the EFI, but it is very different.

If I were in your shoes I'd take Ben up on his offer and swap injectors. Then start with Tony's base config and work your way very slowly and carefully through all the tuning steps. Make sure the LM-1 is setup correctly and reporting the correct AFR to MSI. I would second the suggestion to hookup another LM-1 at the tailpipe to see if you're getting good readings. Also check the readings on all the sensor input to megasquirt. Make sure everything looks "normal".

Just my two cents.

Mac

Scott R · Scott R's Garage

Quote:

Originally Posted by 911Mac

Scott,

Tony's kit comes with 30 lb injectors and the fuel pressure regulator is set to 2.5 bar. This combination makes the injectors flow 27.4lbs/hr. According to Tony that's good for up to 254 HP. Why did you feel like you had to switch to larger injectors? What fuel pressure are you running?
FWIW, getting my SC to idle without hunting required setting all the VE bins around where it idled to the same value.

You're a braver man than me if you're willing to reinstall the CIS. I understand Wayne's point, but What if it doesn't run correctly? The CIS is no less complex than the EFI, but it is very different.

If I were in your shoes I'd take Ben up on his offer and swap injectors. Then start with Tony's base config and work your way very slowly and carefully through all the tuning steps. Make sure the LM-1 is setup correctly and reporting the correct AFR to MSI. I would second the suggestion to hookup another LM-1 at the tailpipe to see if you're getting good readings. Also check the readings on all the sensor input to megasquirt. Make sure everything looks "normal".

Just my two cents.

Mac

I didn't change the injectors, the kit changed for a time, you probably have the Ford black injectors, I have the Python Orange tops, I ran the part number and they are #42/hr As far as setting the bins in the idle area, I have tried 100 ways to sunday to set those guys, probably over a 100 hours alone on the idle bins.

I've gone back to the base config so many times that I have it saved in multiple locations on multiple laptops, the default with idle average bins at 50 is so rich it makes your eyes burn. I'm also on my second LC1, and a Uego borrowed for good measure, not to mention the dyno afr system they used.

As far as the sensor inputs, Tony says they all looked good at last pass a few days ago, although I suspect that MAP sensor has never worked correctly.

BTW **** Here is the video I shot at the dyno, so we can put a picture with all of this info.

doug_porsche · 10-08-2007, 07:11 PM

Scott,

I am in denver and running a BitzRacing MS on my 3.0l. If ya want lets get together and see what we can see.

Doug.

303.876.0113

911Mac · 10-08-2007, 09:17 PM

Scott,
Peeked at your msq file. Your reqFuel is set to 5.8 which is the value you'd use running 30 lb/hr injectors at 2.5 bar. If your injectors are truely 42lb/hr then it sounds like Tony may have been shipped the wrong injectors and not realized it. The reqFuel value affects many of the calculations done by Megasquirt, so if it's wrong, Tony's base config wouldn't even be close. You'll need to recompute it for the smaller injectors you just purchased, but you'll need to know what fuel pressure you're running. Megatune will figure the value for you, I think there's a button you click on. What's the lbs/hr for the new ones?

niner11 · 10-08-2007, 11:29 PM

Scott, I'm fairly new to MS but I run MSII on another turbo car I have and one way to check the MAP input might be to open megatune and look at your KPA with the key switched on and MS powered up. Take that KPA number and convert it to inches of mercury(pretty easy to find conversions using google). Using your elevation you can tell how close your MAP setting is.

When I first fired up my MSII the type of MAP sensor selected in megatune was incorrectly set and the car ran insanely rich until I changed the setting.

I know that the MS forums aren't always busy but Lance over there has a tremendous amount of knowledge and may be of some help. It took me quite a while to get my car running but its has been worth the trouble. Good luck, Chuck

ischmitz · ischmitz's Garage

Chuck, have you looked at his log files? MAP is around 58 at idle (normal) and goes up to 80 under WOT or when the engine is off. Denver airport pressure is 83 kPa - see on page 1. So this seems normal. MAP dips deeper on decel. I don't think it's a setup issue of the MAP sensor. I believe as others suggested he is running with a wrong (too high) setting of "required fuel" and too big injectors resulting in a very rich condition.

niner11 · 10-09-2007, 08:41 AM

Ischmitz, you are correct those values for MAP that you posted should be fine. I am half way around the world without my windows machine....never bothered to load Megalog viewer on the mac so I'm unable to do much with the datalogs or msq.

Sounds like doug_porsche's MSQ is an excellent place to start.

Scott R · Scott R's Garage

Quote:

Originally Posted by doug_porsche

Scott,

I am in denver and running a BitzRacing MS on my 3.0l. If ya want lets get together and see what we can see.

Doug.

303.876.0113

I would be up for that, can you tell me ho your car runs? I'm starting to think I have unreasonable expectations. I think I base everything on my Audi's, maybe it's not supposed to run perfect.

niner11 · 08:57 AM

Scott, I feel your pain but once things are sorted out MS can run incredibly well. There is so much info in the megatune manual that I find myself reading it over and over again when I am tuning my car. Here is an index I bookmarked:

http://www.megamanual.com/megatune.htm#se

edit: just page up to the index, for some reason the page will not bookmark correctly

Scott R · Scott R's Garage

Quote:

Originally Posted by niner11

Scott, I feel your pain but once things are sorted out MS can run incredibly well. There is so much info in the megatune manual that I find myself reading it over and over again when I am tuning my car. Here is an index I bookmarked:

http://www.megamanual.com/megatune.htm#se

edit: just page up to the index, for some reason the page will not bookmark correctly

I use it as a bible, have the entire thing printed out in a binder.

tbitz · 10-12-2007, 08:18 PM

I was just made aware of this thread.

Scott,

All kits were shipped with 30lbs/hr injectors and the base configuration is setup for 30lbs/hr injectors and 2.5bar fuel pressure. The FPR is pre-calibrated and tested by me for 2.5bar fuel pressure.

The python injectors were very used in a very limited number of kits as I wasn't too happy with the quality. Email me the part number of all the injectors, and I'll call to request the flow rate from python. If you truly have 42lbs/hr send them back to me and I'll ship you some 30lbs/hr injectors.

30lbs/hr with 2.5bar fuel pressure have worked on countless kits even those running the smaller 2.7L engine so this is not an issue. First let's be certain of the injectors size and then we can move on to isolating the problem.

The kit has been installed in cars running a 964 cam with great performance, so the cam is not the issue assuming there are no installation issues. By doing an engine rebuild and installing a new fuel system there are many things that could have gone wrong, but we should keep in mind that this EFI setup works with your engine.

If you post in the support group more folks with the EFI conversions can chime in if they have seen similar issues.

Just to note that I worked with one fellow for a year trying to figure out why his car would run great for 5 min and then run horribly. He assumed it was EFI related because that is all that was changed. We tried everything and had check all possible EFI problems. In the end it turned out he had a stripped spark plug thread which lost pressure when the engine warmed up.

I wait for your email.

Cheers,

Tony

tbitz · 10-12-2007, 08:47 PM

Scott,

I was doing my regular seach on Pelican archives after I made the above post to see if there were any other posts from folks with EFI issues and found the following reply from you in another thread:

Quote:

Originally Posted by Scott R

I don't know how to compare cams, however I'm running a 964 grind from Camgrinder, and high compression, my EFI is tuned perfectly for it. I have a dead steady idle, plenty of power where I need it, and good millage.

http://forums.pelicanparts.com/porsche-911-technical-forum/362603-early-car-efi-conversion-sources.html#post3434097

What has changed in your car in the last two months to go from perfectly tuned, dead steady idle and plenty power to the problems you are having today?

Please let us know if something has changed since then, so we can get to the bottom of the problem you are having today.

Cheers,

Tony