I am getting SO SICK of my car dying! Please help!

Davin · Post by **Davin** » Fri Jun 29, 2007 4:05 pm

My car starts great when cold, but over 180-190 degrees, it surges and dies EVERY TIME. It would be so nice to have a car that would just run. I've researched some and tired some fixes but nothing seems to work. Here are the SCALER changes I have made:

Scaler Name: Action Taken
EGR System Type changed from "0" to "2"; 2 = off
Idle in Gear (RPM) changed to "720"
Idle in Neutral (RPM) changed to "720"
ISC Maximum Drive RPM changed to "840"
ISC Maximum Closed Throttle Idle changed to "840"
Engine Displacement changed to "347"
fan_high_speed_ECT1_on changed to "196"
fan_high_speed_ECT2_on changed to "200"
fan_high_speed_ECT_off changed to "190"
fan_low_speed_ECT_off changed to "182"
fan_low_speed_ECT_on changed to "188"
Injector Slope High changed to "30.5"
Injector Slope Low changed to "38.5"
fuel_injector_breakpoint 0.00001975
fuel_injector_min_pulse_width 0.000005
Load Scaling Switch changed to "0"
spark_adder_global changed to "6"
Thermactor Present changed to "0"

I have taken the values in the "fuel_crank_PW_multiply_ECT" and
"Injector Offset V Batt Voltage" Functions and modified them by a factor or .63 to reflect my 30# inj (19/30=.63)
My MAF file is the stock PROM_30.MAF file that comes with the install.

I've made minor chages (+2-4 degrees) in the spark tables but the problem has been around before that and going back to stock tables does not improve matters. Please help me solve this once and for all.

Thanks

Post by **2Shaker** » Fri Jun 29, 2007 5:21 pm

You need to modify the start-up table too. I seem to recall cutting the values by around 50%. Crank is only while you are cranking. Start-up takes you from post crank to the end of the corresponding values (time and temp), then it's on stabilized OL fuel table and then closed loop. I would not have applied the factor to the battery vs injector offset - reset that to stock for now (but resetting this will have some effect on the rest of your tune depending on what you actually did).

Davin · Post by **Davin** » Fri Jun 29, 2007 5:46 pm

Thanks for the reply
The only function I see that talks about startup is "ISC Startup RPM vs ECT", nothing about fuel...is that what I should drop by 50%?
the scalars that talk about startup are ISC Startup RPM time adder, ISC Startup RPM adder,and ISC Startup Kickdown timer. Should any of these be affected?

Cougar5.0 · Post by **Cougar5.0** » Fri Jun 29, 2007 9:33 pm

I think he meant Fuel Table - Startup.

Post by **2Shaker** » Fri Jun 29, 2007 10:30 pm

ooops, I was in a hurry and tried to answer quickly off the top of my head. In CalEdit 1.30B it's called base_fuel_table_cold_enrichment_decay. In 1.30A10 I think it was called Fuel_Table_Startup or something like that. If you re using Bin Editor I don't know if it is named the same as CalEdit 1.30B and I don't have BE close by at the moment so I can look it up. The values in this table are subtracted from LAMBSE values thereby richening the mixture. The problem you describe sounds like an overich condition and is a common startup when warm problem when you install injectors bigger than stock. Don't hesitate to come back here and ask for more clarification if needed.

Davin · Post by **Davin** » Sat Jun 30, 2007 9:10 am

I would have replied sooner but I could not get on the site, some kind of debug error message, I guess it was getting maintenance? Anyway, I do have a table (not function) called "fuel_table_startup_OL" I don't know what OL stands for but this is the closest thing I see to what you are describing. It looks alot like the Fuel Table - Startup table in the "TweecerDefs" spreadsheet. Only real difference is that which time (sec) on that sheet span 0-28 sec, mine is more like 0-240 sec. Do you think this is the right one?

Cougar5.0 · Post by **Cougar5.0** » Sat Jun 30, 2007 10:11 am

Sounds like the one. OL stands for Open Loop as the car is in open loop until it warms up and this table is used to ramp from rich at startup to close to stoich over time.

Davin · Post by **Davin** » Sat Jun 30, 2007 10:42 am

duh!..I feel dumb, but thanks. I returned the PW v Batt to stock and multiplied the entire Fuel Startup table by .63. Gonna take her out soon so we shall see.

Davin · Post by **Davin** » Sat Jun 30, 2007 4:13 pm

well, no change from that, do you think I need to take more out?

Davin · Post by **Davin** » Sat Jun 30, 2007 4:22 pm

I just re-read and saw that 2Shaker had suggested 50%. I'll give that a try...

Davin · Post by **Davin** » Sat Jun 30, 2007 4:58 pm

Okay, I must admit I was hopeful but changing the settings in that table by a factor of .63, .5, .4, and then .3 had little effect. Once of twice when dipping down below 450 rpm the engine would surge and try one more time instead of stall, but it would still stall soon after.

Davin · Post by **Davin** » Sat Jun 30, 2007 5:06 pm

BTW I don't know if this is a factor, but usually when I first try and start it when its hot, it will surge and idle for around 5-10 seconds at around 850-950 RPM before dropping and stalling. (note: I have Idle set at 720 rpm). Is this definitly the startup or could it be stabalized or something?

stanger007 · Post by **stanger007** » Sat Jun 30, 2007 5:49 pm

Try zeroing out the table below for kicks...

Binary Editor table name: "Startup Fuel Table"
CalEdit table name: "base_fuel_table_cold_enrichment_decay"

Table description: "Value subtracted from base fuel tables for warm up enrichment"

Modifying this table has helped me with the same problem on two Mustangs.

Wes

Post by **2Shaker** » Sat Jun 30, 2007 9:08 pm

Davin,

What are the values you have in the 90 - 150 degree range?

Davin · Post by **Davin** » Sat Jun 30, 2007 10:10 pm

wes - can't find a table remotely like "base_fuel_table_cold_enrichment_decay" in v1.30A9 CBAZA but if you can direct me I'mall ears.

stanger007-
at stock *.3 :
90 120
240 0 0
120 0 0
60 0.11442 0.11442
20 0.11442 0.11442
15 0.34325 0.34325
10 0.34325 0.34325
5 0.34325 0.34325
0 0.22883 0.22883

Stock *.5:
ECT 90 120
240 0 0
120 0 0
60 0.228835 0.228835
20 0.28604 0.28604
15 0.5721 0.5721
10 0.5721 0.5721
5 0.6865 0.5721
0 0.457665 0.40046

stanger007 · Post by **stanger007** » Sat Jun 30, 2007 11:17 pm

Davin - I'm on the beta build of CalEdit - v1.30b3. The table must not be in the older version or is stored under a different name.

A friend of mine brought his Mustang over today after getting his exhaust put on (we installed a Trickflow kit on it a couple weeks back) and he was having idle issues. After setting the idle mechanically we still had a surge on hot start. Went and got gas and he started it, surged and died if not given gas. I had my laptop out datalogging so I zeroed out the table just to see if it had any effect and the next crank (and every one after that) was surge free. No more stalling or surges. :)

Wes

Post by **2Shaker** » Sun Jul 01, 2007 8:14 am

Davin,

You must be on CalEdit 1.30A9 or A10. In those versions of CalEdit the table is named "fuel_table_startup_OL" as you indicated above. In CaleEdit 1.30b3 Mike renamed it to "base_fuel_table_cold_enrichment_decay" which is more descriptive of what it is.

This table has coolant temperature values on the X axis, and time in seconds on the Y axis. The values in the cells are subtracted from the commanded LAMBSE (AFR) values which will richen the mix. Notice how the values get smaller as time goes on, and notice how much smaller and fewer entries there are as the coolant temperature gets higher. So if you start the car and the coolant temp is 70 degrees because it hasn't been run in a while then it will get more fuel, for a longer period of time than if the coolant was at 180 degrees and the car has been off for just a few minutes. This logic is emulating a choke from the carburetor days.

Setting the values to all 0's might work when ambient temperatures are high during the summer. But one cool day and you might find yourself not being able to get it to get it going at all. The values you have in those 2 columns I asked for (above) at the "stock *.3" are very close to mine. Something else might be causing your problem. Is your temperature sender working? Have you changed the "crank_fuel_pulsewidth" settings? What else have you done? Is this a new problem that has started after you made some other recent change to the motor or your tune?

Davin · Post by **Davin** » Sun Jul 01, 2007 9:07 am

stanger - I'll give the zeroing a shot.

2Shaker - Everything I have changed (except the spark tables) is listed in the original post. I have modified the function "fuel_crank_PW_multiply_ECT
" by a factor of *.63 but I have not toched the table "fuel_crank_pulswidth". I'm guessing that you are thinking it may be creating a condition that is too rich before it even gets to the startup table?

Also, can either of you tell me what conditions the "fuel_table_base_OL" and "fuel_table_stabalized_OL" are used, since I have not changed them either...

Davin · Post by **Davin** » Sun Jul 01, 2007 9:39 am

okay, I loked up those tables and I guess they are commanding AFR. Since my load at startup is usually 27-32% the tables have me at at least 14:1 so I doubt the problem lies there.

My ACT readin on a hot start can be anywhere from 115-155 degrees (I live in FL). My vlaues in fuel_crank_pulsewidth for the 120 degree column range from .09375 (@ - 40 and 0) to "1" for the rest of the rows. Not sure what this vlaue is though.

Also, I seem to remember reading something about long tube headers causing problems and the need to modify the exhuast Pulse Delay table. I do have LTs and have not modified this table if that means anything to you.

Post by **2Shaker** » Sun Jul 01, 2007 12:11 pm

Davin,

I believe the startup values are applied to the base fuel table. The stabilized fuel table OL is used after the EEC has finished the startup routine or anytime you are in OL. I would not modify either of these, at least not for this problem because they would affect so many other things.

Lets make sure I understand your scenario. Immediately after it starts to run it starts to go rich on you and "hunt (surge). Well how long does this last and does it ever get to closed loop? My car goes to CL shortly after the startup logic has timed out (based on the start up table). Even when mine had the same problem you have, before I discovered startup, it would clean up once it got into CL. Are you forcing OL all the time (I can't remember)?

Also, I've never taken the time to figure out how to set the injector breakpoint scaler. I know what it does, and I know EEC analyzer will tell you what to set it at, I just never got comfortable with it. So I have opted for the same approach Ford took on the Cobras - I set the High and Low SLopes to the same value which eleiminates the need for the breakpoint. You might try that just as an experiment to eliminate the breakpoint as a possible issue.

Davin · Post by **Davin** » Sun Jul 01, 2007 1:14 pm

No, I'm not forcing CL. When the car is hot, I start it up and it has a high idle around 900-1000. It stays there for 20-45 seconds and then surges once or twice (~1700) and then dies. Each subsequent start will die much quicker. If I start hitting the gas and keep it from stalling long enough it will eventually be okay. This might be b/c it enters CL but frankly I have not yet logged it to find out if this is the case or how long that time period really is. If I knew how long that period was, I could keep it up right until that point and then see if the CL takes over. How do I find out how long a period that is?

If I set the HS and LS to 30#, is there a different value I need to shut off the breakpoint or does it simply become irrelevant?

Cougar5.0 · Post by **Cougar5.0** » Sun Jul 01, 2007 4:27 pm

Davin wrote:
If I set the HS and LS to 30#, is there a different value I need to shut off the breakpoint or does it simply become irrelevant?

Breakpoint controls the transition from high slope to low slope (it's gradual and many times you never use the low slope completely). If high & low slope are the same, it becomes irrelevant.

Cougar5.0 · Post by **Cougar5.0** » Sun Jul 01, 2007 4:46 pm

BTW, I had a problem like yours. I would have it happen in the staging lanes at the track - it was the most annoying thing ever. One thing you might notice is that the HEGO's will stay rich or lean and never switch. Have you looked at logs? Why are you guessing as to what is happening? - don't you have logging available? These kinds of problems are much easier to solve if you have actual data of what is going on when it happens. With long tube headers and not adjusting the Delay, I can imagine that you are having problems. It's easy to get the loop timing out of synch without adjusting for the longer delay that it takes for exhaust to get to your O2's.

Davin · Post by **Davin** » Sun Jul 01, 2007 5:35 pm

Cougar, good segue...

I just got back from some data logging. The first time I heated the ECT to 194* and ACT to 104*. I started the car and it reached CL 40 seconds and was fine. I then drove some more and repeated the experiment. ECT 188* and ACT 116*. I tried starting it and it died at 32 seconds bf it could reach closed loop. If I hold my foot on the throttle long enough for it to reach CL (in my case 39.5-40 seconds), everything is fine.

The last time I logged LAMBSE and it seems to be around 10.8-11. When it hits CL, it takes about 2-3 seconds to transition to LAMBSE of over 14. Is this helpful, anything else I could report that would help you guys tell me what's going on.

Toy 94 GT · Post by **Toy 94 GT** » Sun Jul 01, 2007 7:19 pm

I had the exact problem with both my 24# before the SC and the 42# with the KB. I never figured it out with the 24# because I was using the Cobra tune snd figured all the fuel adjustments were right. Once I went to the 42# I had to play. I did the same as yau and multiplied all the values the the fuel_crank_pulswidth by .57 24/42. What I found out was that was to low. I have all the values in that table at .75. The only issue I have now is I need to give it just a little pedal when starting and I think that the values are just a tad high. But it starts right up with no surge.

Hope this helps
Bruce

Davin · Post by **Davin** » Sun Jul 01, 2007 8:11 pm

Hmmm. Here is my problem...according to the base fuel table cold, my lambse should be targeted around 14.073 at 30% load and 180 degrees ECT (the typical conditions of a warm start for me). Yet, when I start my car, the targeted lambse is less than 11. Realisically, regarless of if the base_fuel_table_cold_enrichment_decay adjustment, the commanded lambse still doesn't seem like it should be that low. I just wonder what is making that commanded lambse so low.. the values I'm getting are as if the engine ECT was at 60 and not 180.

BTW, I was noticing that the function "Open Loop Fuel Multiplier vs ACT" is used against the base fuel table and causes a richer condition as air temp goes up. At 116 it is x1, by 126* it drops to around .78. This seems that this may be the multipler causing the lambse to be to low. The question is should I try adjusting the multiplier to get a leaner lambse on warm start or is the real problem that the fuel tables or injector slopes are off and not achieveing the proper lambse?

Davin · Post by **Davin** » Tue Jul 03, 2007 7:18 am

thanks for the replies everyone. It appear that I have not been successfully clearing my KAMs, so its back to try all these methods over again. I'll let you know how it turns out.

Post by **2Shaker** » Tue Jul 03, 2007 12:15 pm

Davin,

I don't know whether the KAMs play a role when you are in the startup table or not - I would think they would not be part of the equation.

Davin · Post by **Davin** » Tue Jul 03, 2007 9:00 pm

well I fed my factory MAF data into the 10 to 30 point utility on the new CAL EDIT version on came up with a MAF transfer taht was leaner than what I had before but richer than what I had found online. I then set the base fuel ol decay table to *.63 (19/30) and the car stalled when starting hot. I tried what stanger 007 suggested and set the table to zeroes and it actually got to CL without stalling, a big improvement!. Finally I changed the base ol fuel decay table to *.25 of stock and it still worked. It seems that somewhere between 63% anf 25% it is working out. I am glad that it seems to be improving but I would really like to konw why>>>

stanger007 · Post by **stanger007** » Tue Jul 03, 2007 9:45 pm

Good to hear man.

Good luck with the tuning,
Wes

I am getting SO SICK of my car dying! Please help!

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