fsvaasam

Unplugged harness today and tested pressure.
When cold gauge needle vibrates like crazy between 175-225 and when it warms up, it bounces between 210-225 so it calms a little.
Reverse bounces between 250-260.

And just like cherry on top, when i did all this in about 15 minutes, i started to hear a little grinding noise in every shifter position. I have lokar shifter so small noises comes cabin easily. Noise stopped only little bit of time, when changing shifter position.

Taking any suggestion where have i screwed up?

bbond105

I think the gauge needle vibrating is normal, I’m not sure thought as I have only used a pressure gauge once. IIRC mine was vibrating also. As far as the grinding noise I have no idea.

fsvaasam

Should unplugged pressure be more like close to 300psi everywhere?

When plugged 75 is steady needle at idle and reverse steady 110.

fsvaasam

This amazes me too when plugged. I have steady 75 psi when slowly adding idle to revs 5000 or something. When blipping pedal from idle it bounces high. There is no logic to me.

bbond105

The high pressure should be around 230. Your low pressure is a little low but that could be because you have a low idle speed. Low pressure should be around 90 with the boost valve that you have 75 stock boost valve.

The PCM uses the TSP and MAF sensor to sense engine load and adjusts trans line pressure accordingly. Just raising the engine RPMs in park or neutral without a load on the engine will not Couse the PCM to raise the trans line pressure any large amount. When blipping the pedal as you say, it places a small load on the engine and therefore a higher line pressure.

Check your pressure while power braking but only for a few seconds just long enough to read the gauge and then get off the pedal or while driving. If you power brake for very long you will over heat the trans.

fsvaasam

Plugged harness again and small grinding noise was gone. I dont know what it was and it came in warm and max pressure, so it can relate to that. I think no worries now.

Did some power braking and getting 175 when tires brake loose. Continued this burnout and saw above 200.

Also went in third gear WOT and it dont go to limiter anymore, so sonnax boostvalve did something here now.

Im worry about when accelerating WOT i can see only around 150 psi.

Should there be max pressure in use when WOT?

fsvaasam

This is starting to look like i have issues with tune here.
I have Texas-speed flashtune PCM.

I tried today with other stock tune PCM and of course i cant drive the car, but i can compare pressure rise that way.

When i started the car, pressure gauge needle jumps along easily when slowly adding revs. I tried power braking in my garage and i saw +175 psi without smoking tyres on a slippery epoxy floor.
So with stock PCM my pressure starting to build up more early and constant.

I dont know if Texas-speed change the table here, but seems there is significant difference how pressure gauge acts with these two different PCM.

bbond105

It could be in the tune. I'd call TSP and ask if they changed anything in the trans tables.

fsvaasam

I might ask them if they did changes, but could it be even something smaller thing like TPS or MAF calibration?
I dont know anything about these LS tuning software, just guessing.

Since i have to do corrections to PCM anyway i have to purchase my own sofware.
There is not much people here around to help and i have to learn to use.

HP tuners or EFIlive? I want easy tune as possible, so should i have some wideband version for tuning on road? What are you suggesting here?

bbond105

Yes a defective TPS or MAF sensor could cause that problem, but if a different PCM made the problem go away, I would think it is something in the tune or PCM.

I’m not a tuner so I can’t recommend which to use. I think most people use HP tuners, but I could be wrong.

mrvedit

Yes, HP Tuners seems to be more popular here, at least with us amateurs. Many of the pro tuners seems to prefer EFI Live.

Sorry not to have been as active here as usual, but Mr Bond is doing a great job answering your and other questions.
As he said, if changing PCMs changed the trans behavior, then the tune needs to be checked.

If you are sure the PCM is properly tuned for the engine, e.g. stock PCM and stock engine, then it is safe to disconnect the MAF for testing purposes. If the trans then shifts properly, I would try a replacement MAF.
The TPS is critical, but can be checked with even basic scanners. Hook up the scanner and make sure the TPS % varies from 0% to 100% (or at least 95%+). If if does not read 0% with the throttle closed I would suggest going through the TPS reset procedure; granted this won't affect your trans shifting, but can affect idle quality and prevent dying/surging as you slow down to a stop.

fsvaasam

Little update here, but not much. I found a friend nearby, who have EFIlive and he is still rookie too and learning it. Mostly he knows about engine tune.
We had both my stock and TSP pcm connected and noticed not much difference between tables.
We see that commanded amperage were differend between PCMs and pressure gauge needle vary 0-1A good when commanded.

I just ordered my own HP tuners today and starting to lear it soon so i can figure out and learn better.

My guess its still mostly with MAF tune, but still pure guessing. Like to know.

Is there any tuner who can say what parameters are affecting most to forcemotor command?

fsvaasam

Okay my old thread but i didnt tell you any conclusion here.

It ended up being tuning issue. Guess your mailorder tune is out from gas we use here in europe or something similar.

After real tune it was hitting rev limiter sometimes 2->3 but no slipping occurred.

I tried adding 1/2 quart oil cause it was easiest thing for me to do and BOOM.

Problem solved!!

I really wanna thank you all active members here who are willing to help, so THANK YOU

mrvedit

Glad to hear that you now have everything working.
And thank you for updating the thread.
I'm going to close it, but PM me if you want it open again, or just start a new thread.