PTE 550 Tuning issues

**Jimvr4** · 02-27-2014, 10:13 PM

First, make sure the coolant temp has stabilized. Idle (low trims) don't even get adjusted until then. O2s also don't cycle until they warm up either. After things get warmed up the O2s look normal. Low trims are between -12.5 and +12.5. You have to wait up to 20 minutes for the low trims to stabilize as they only get adjusted like every 4 minutes. So just let the car idle and watch it. After around 20 minutes the low trims will settle where they will be. If they settle higher than +12.5 then add to the VE below 100 Hz and if they settle below -12.5 then take away from the VE below 100 Hz.

Oh and don't go by the wideband in idle until you are absolutely sure you have it calibrated correctly in Chrome. Make sure you don't touch the Evoscan formula for the WBScaled.

**TKIs** · 03-01-2014, 04:01 PM

Thanks for the reply Jim. I spent most of yesterday trying to get the low trims set. No luck. The best I got was -9 rear and +8 front. Also I noticed they never seem to stabilize even after 20 + minutes. I watch then cycle for a while and they would move 3% back and forth. In other words -9 +8 would go to -6 +11 and then come back down on the next cycle but no matter what i did to the VE table I could never get them any closer together than 17%. In comparison when I first set them up granted they weren’t good but they were 7% apart.

I also took the car out to see what the mid trims were doing. After about 2 hours and making adjustments to the VE table every 20 minutes the closest I was able to get them was -4 +5. In comparison there they used to be +-3% when I first set them up.

I did see that if the trims are further apart than +-5 then I need to rescale my injectors. Originally I had them scaled at 554 but like I said in my original post I read in a few different posts that they don’t flow that much so I scaled them back to 535 when I tried to set the trims. I’m not really sure where to go with them. I guess I can try to scale them back up to 545 or 554 and try to set the trims again and see what happens.

The thing that has me most confused at this point is the hard start issue. The car always started perfectly before I installed the injectors. Like I said in my original post I managed to get the cold start end of it resolved by lowering the cranking IPW values but warm starts are still a problem, but should I even have to adjust the startup tables? From the way I understood what I read in Greg’s post it should only be needed for 720cc injectors and above. Am I understanding this correctly?

Here are all the issues since installing the injectors.

1) Originally did not want to start when coldt When the car finally started it let out a plume of smoke. Smelled like raw fuel.
2) Warm start takes about 20 seconds of cranking over before it finally starts up.
3) Exhaust smells pig rich at idle.
4) Randomly going lean at idle. (The wideband is scaled properly. Adam confirmed that for me when I first got my ECU)
5) Going lean at takeoff until the car warms up. Sometimes the car wants to shut off.

Here’s what I’m thinking so far.

1) I’m misunderstanding something, missing something or royally screwing something up.
2) The latency values I’m using aren’t working for my car.
3) I have an intake leak that i missed (Although i did a pressure test up to 15psi the other day and found nothing)
4) I have an exhaust manifold leak that I missed.
5) What ever my low trim issue was to begin with was amplified by the bigger injectors.
6) The injectors are junk
7) See number 1.

I’m really not sure what to try next other than rescaling the injectors. Any more thoughts?

Originally Posted by Jimvr4

First, make sure the coolant temp has stabilized. Idle (low trims) don't even get adjusted until then. O2s also don't cycle until they warm up either. After things get warmed up the O2s look normal. Low trims are between -12.5 and +12.5. You have to wait up to 20 minutes for the low trims to stabilize as they only get adjusted like every 4 minutes. So just let the car idle and watch it. After around 20 minutes the low trims will settle where they will be. If they settle higher than +12.5 then add to the VE below 100 Hz and if they settle below -12.5 then take away from the VE below 100 Hz.

Oh and don't go by the wideband in idle until you are absolutely sure you have it calibrated correctly in Chrome. Make sure you don't touch the Evoscan formula for the WBScaled.

**Jimvr4** · 03-01-2014, 07:13 PM

My way of thinking about the trims is that as long as they aren't pegged at -12.5 or +12.5 they ARE set as well as they can be given the components. So that brings the next question. Do you know the history of the injectors? Were they cleaned and flow tested? How about the O2 sensors - are they unknown age? You may want to consider buying new ones if that is the case. Also the MAF needs to be connected and providing stable air readings, intake temp, and baro. The motor should be pulling a healthy vacuum of ~ -450mmHg.

**J. Fast** · 03-02-2014, 12:14 AM

If you have a vac gauge I would hook it up once the engine has reached operating temp and evaluate how much vac the engine is generating. Also, what plugs and wires are you using and what's their condition? Do you have your stock ECU still?

**Greg E** · 03-02-2014, 03:42 PM

Are you really sure you don't have an intake pipe popped off?

**TKIs** · 03-02-2014, 08:11 PM

I bought the injectors used so I'm not sure about the history. I did send them out to Pro Flow to have them cleaned and flow tested before I put them in. I was told they checked out. The o2 sensors were replaced about a year ago. The MAF is definitely plugged in. I'll do some logging on the air flow, temp and baro tomorrow. The vacuum at idle is 457 mmHg (18 inHg).

Originally Posted by Jimvr4

My way of thinking about the trims is that as long as they aren't pegged at -12.5 or +12.5 they ARE set as well as they can be given the components. So that brings the next question. Do you know the history of the injectors? Were they cleaned and flow tested? How about the O2 sensors - are they unknown age? You may want to consider buying new ones if that is the case. Also the MAF needs to be connected and providing stable air readings, intake temp, and baro. The motor should be pulling a healthy vacuum of ~ -450mmHg.

**TKIs** · 03-02-2014, 08:39 PM

Thanks for the reply. The plugs are NGK PFR6J's gapped at .32 and the plugs are Autolite 7mm's. Both replaced about 5k miles ago. I pulled the plugs in the front and they're definitely fowling out. I didn't get a chance to pull the back ones but I will tomorrow. The vac at idle is 18 inHg and the ECU is one of Adam's.

Originally Posted by J. Fast

If you have a vac gauge I would hook it up once the engine has reached operating temp and evaluate how much vac the engine is generating. Also, what plugs and wires are you using and what's their condition? Do you have your stock ECU still?

**TKIs** · 03-02-2014, 08:43 PM

Thanks' for the reply Greg. I checked all the intake piping made sure everything was in place and did a another pressure test and didn't find any leaks.

Originally Posted by Greg E

Are you really sure you don't have an intake pipe popped off?