Engine won't start

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ToxikFlame

Member
I recently bought this donor and it appears to me that the engine is flooding with fuel and either won't start, or will only run for ~5 seconds.

I have tested the injectors and they aren't leaking and I confirmed the fuel pressure wasn't really high.

The previous owner mentioned that he had gotten a tune from ZZP but they were having trouble with it and I began to wonder if something was off there. The engine has 60# injectors, 2.8 pulley, larger intake, upgraded exhaust. Probably some other things, but I haven't found it and documented it yet. My initial thought was that maybe the tune file he got from ZZP wasn't set up for 60# injectors.

I ordered HP Tuners and got the tune out of the car and included it below. I would love if someone would take a look at it and point out any major flaws they see that might be preventing it from starting. Below are a few of the oddities I saw.

Note: This is the first time I have ever looked at tuning an engine and am trying to slowly get my head wrapped around all the data.

1. Dynamic Airflow appears to be turned off. Disabled above 100 rpm.
2. Fuel Flow Rate does seem low. From what I have read, it looks like this has to be somewhat tricked using the Flow Rate Mult which is still at 1.0.
3. Short Pulse Limit seems high and adders seem high.

That's about as far as I got before I realized I should ask for some input on this initial file before I go start messing things up.

I appreciate any help you all can provide

Tox
 

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Desert Sasqwatch

Desert Sasqwatch

Goblin Guru
Wondering who played with the program before you got the car? Racer Boi thinking that with all of the bolt on goodies that the engine needed a lot more fuel...maxed out should do the trick! :rolleyes:o_O:eek:
 
ctuinstra

ctuinstra

Goblin Guru
Holy Batman! That file has had about everything messed with!!! Give me a minute to digest some of this and report back.
 
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ctuinstra

ctuinstra

Goblin Guru
ToxikFlame said:
I ordered HP Tuners and got the tune out of the car and included it below. I would love if someone would take a look at it and point out any major flaws they see that might be preventing it from starting. Below are a few of the oddities I saw.

Note: This is the first time I have ever looked at tuning an engine and am trying to slowly get my head wrapped around all the data.

1. Dynamic Airflow appears to be turned off. Disabled above 100 rpm.
2. Fuel Flow Rate does seem low. From what I have read, it looks like this has to be somewhat tricked using the Flow Rate Mult which is still at 1.0.
3. Short Pulse Limit seems high and adders seem high.

Tox
Click to expand...
I'm not pretending to be an expert, but I'm a believer in stick close to stock and only change things that need to be changed and if you know for sure what you are doing. This file has just about everything changed, kind of a mess in my opinion. There are some things that I agree with and there are other things that may be slight differences in the model/year between your stock settings the the stock file I have.

But a couple of notes on your findings before I continue.

  1. Dynamic Airflow is turned off. You are correct. I don't know why they did that. It can run good with it turned off if everything else it tuned well. When I got my car tuned better, you could not tell it was turned of. I think it should be on.
  2. There is a lot of debate about the flow rate and "tweaking" and "tricking" the ECM. It's all bunk! The dyno tuner I took our car to doesn't believe in any of the tricks and he made a believer out of me. I have 60lbs injectors (with a boost referenced fuel pressure system) and I don't have to trick anything. Just properly tune the VE tables and the MAF and it runs just fine.
  3. Not uncommon to adjust the short pulse adders when going to bigger injectors. Bigger injectors don't work well with very short pulses and they start to act funky. I'm not sure they have to be adjust quite as much as these are, but not uncommon.
 
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ctuinstra

ctuinstra

Goblin Guru
Here is a list of items that are not stock. Keep in mind, this is using the OEM stock file I have and your stock settings may have been different. This may contribute to more items not being the same that actually aren't causing an issue.

24459

24460

24461
 
T

ToxikFlame

Member
I found a stock '06 SC tune in HP Tuners repository. Is there risk (and if so how much), in starting over? Try putting that in and see if it will run?

Thank you @ctuinstra for taking a look!
 
ctuinstra

ctuinstra

Goblin Guru
I'm not going to comment on every change, but I leave a few comments on a couple of highlights. Maybe we can work on a good base tune for you to try to get the car going again and then tune from there.

  1. The Idle Airflow has been tweaked a lot. This must be in an effort to fix the idle problem. I never touched any of these settings.
  2. The MAF Calibration is different obviously and it will be. It's not terribly off.
  3. The VE table has most of the values much lower than I would have expected. A good data logging and tuning will only tell you if it's way out of whack.
  4. As you mentioned, Dynamic Airflow is disabled.
  5. Injector flow rates seem reasonable for the 60lbs injectors. Along with the pulse corrections and min limits.
  6. Piston protection has been disabled. Not sure why they do that.
  7. Power enrichment has been increased in many areas. Typical of tuning, nothing wrong with adding a little extra fuel during long hard pulls so as not to burn pistons.
  8. RRM redlines are maxed out. Best to get the car running correctly before hitting the 'ol rev limiter!
  9. The entire spark tab has been adjusted. Some may be trying to correct idle issues.
  10. Without fail, ZZP loves to disable the Spark Retard in Torque Management, this makes the throttle undriveable in a Goblin. They just zero it out. Great for throttle response, but horrible trying to control the touchy throttle.
  11. And a couple of the boost limiters have been modified, not the worst thing in the world, I disable most of the boost limiters on ours.
  12. Many of the DTC (check engine) codes have been disabled. I guess if you can't fix them, disable them.
  13. The intercooler pump has been changed to turn on all the time. I like this, I have mine set that way. Easy to check if it's working when you start the car.
  14. Last, but not least, the speed limit has been raised.
 
ctuinstra

ctuinstra

Goblin Guru
ToxikFlame said:
I found a stock '06 SC tune in HP Tuners repository. Is there risk (and if so how much), in starting over? Try putting that in and see if it will run?

Thank you @ctuinstra for taking a look!
Click to expand...
Post that file. I want to see if it's the same as the one that I have. I think it would be a good idea to start with that but you will need a few changes to work well with the larger injectors. I will have to see if I can use some of the settings (before my BRFS) and modify the stock tune for a good baseline. For the best results, proper tuning will make it run the best.
 
ctuinstra

ctuinstra

Goblin Guru
I’ll take a look at it and make a tube file you can try.

I don’t suppose you have a fuel pressure gauge?
 
T

ToxikFlame

Member
I have a fuel pressure test kit. I ordered a gauge yesterday to mount on the rail. It should be here tomorrow.

When I tested it before pulling the tune, it was at 50.
 
ctuinstra

ctuinstra

Goblin Guru
Here is a file to try. This is basically stock with a few changes for the 60 lbs injectors. A summary of the changes from stock.

  1. Used stock VE table but smoothed it out a bit. Most of the values are very close to stock.
  2. Increased the injector flow rate +10 from stock. The curve is the same, but maxes out at 62.2.
  3. Ramped the Power Enrichment and increased the ramp rate. This adds a bit of safety.
  4. Turned off the COT adder (catalyst adder since you don't or won't have a cat).
  5. Put the RPM cutoff back to 6500 for P/N.
  6. Corrected Max Boost % from 200% to 100% (limits of the adjustments?).
  7. Turned off the Catalyst Test, again since you won't have one most likely.
  8. Kept VATS turned off (stock was turned on and I didn't want to turn it back on if you needed it off).
  9. Enabled the intercooler pump to start immediately and not wait.
  10. Disabled the A/C (if you are going to drive the donor and want the A/C, you will want to turn this back on).
  11. Re-enabled ALL DTCs. You may very well get codes now that you didn't get before. This could be a very good thing. Instead of hiding some of the issues, let's see the codes and work on them. This can be changed again later.
I offer no guarantees that this will fix your issues and make your car run great. This is simply to get to back the basics and remove all of the "tweaks" to see if we can get the car to run again. If it does run, please do NOT go racing around without further tuning. Also, all of the timing has be reset back to stock, it was advanced for power gains, but it's best to put it back to stock and then work on the timing later as it's running well again.

I hope this helps. If not, you may have other issues going on that need to be addressed.

24478
 

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T

ToxikFlame

Member
hmmmm. I don't know. Still feels like maybe over fueling, but I ran out of daylight to really check. Loaded your new tune in and it did fire up. I have attached a log file. Not sure if it's of any use, but I'm learning to use the software. When it's daylight tomorrow I'll check again. I did take a look at the spark plug in cylinder 1 and it was pretty wet.
 

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ctuinstra

ctuinstra

Goblin Guru
Not much there to work with. The only thing I can see is the commanded AFR is really low. Not uncommon for it to be rich during start but it's high is 10.5 and then drops again from there. Maybe it's trying to keep it running by going really rich. I'm thinking there is something else wrong that isn't going to be tuned out. That stock tune should have run. Maybe see about trying a set of stock injectors and a stock tune??? I have another set of 60lbs injectors, but that may not help much.
 
ctuinstra

ctuinstra

Goblin Guru
Have you tried without the MAF plugged in? It's not the best method to check it. We could disable it in the tune to see if it will run off the VE tables. The MAF also contains the air intake temp sensor, so unplugging it will cause it to read extreme cold and will riches it up more. But it may at least tell you something.
 
T

ToxikFlame

Member
I tried it before. I'll retry again with this tune tomorrow. I noticed in the log that MAP want linked. Is that normal on startup?
 
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