misses when under hard bost

thebuddrik

New Member
Jun 2, 2007
149
0
0
45
Lafayette ,La.
learn me something IJ. how come it misses when im agressiveally accelerating and not when already at speed? could it have something to do with the timing advance?
 

thebuddrik

New Member
Jun 2, 2007
149
0
0
45
Lafayette ,La.
that is most probably it but i cant do nothing about that for now. i will just need to pull off the coilpack and get jiggy with it and a multi meter
 

Grimsta

Supramania Contributor
May 30, 2007
1,081
0
0
Santa Rosa, Ca.
Well you said you had your timing really advanced right? Have you retarded it to see if that handles it yet? Lets quit with the chit chat and get some hands on.
Set timing back to base and see if it still misses. How much are you boosting at? What grade fuel you using? How many miles has the car had this problem for?
YOu say if you accelerate it wont miss until high RPM, you say if you down shift it misses. Because when you down shift you are in high RPM, this sounds like a high RPM miss. Can sensor may not be able to keep up in high RPM is one possibility, another possibility is detonation. Use a higher grade fuel, or check your fuel filter for clogging. What kind of plugs are you using? If you're boosting high, try a colder plug
 

thebuddrik

New Member
Jun 2, 2007
149
0
0
45
Lafayette ,La.
Grimsta;1023376 said:
Well you said you had your timing really advanced right? Have you retarded it to see if that handles it yet? Lets quit with the chit chat and get some hands on.
Set timing back to base and see if it still misses. How much are you boosting at? What grade fuel you using? How many miles has the car had this problem for?
YOu say if you accelerate it wont miss until high RPM, you say if you down shift it misses. Because when you down shift you are in high RPM, this sounds like a high RPM miss. Can sensor may not be able to keep up in high RPM is one possibility, another possibility is detonation. Use a higher grade fuel, or check your fuel filter for clogging. What kind of plugs are you using? If you're boosting high, try a colder plug

Timing is base. Plugs are denso, factory toyota plugs from toyota. The wires are a year old. Fuel is premium. Car is stock, not even an exhaust. The car ran fine until I burnt a valve. I had the head rebuilt to toyota spec. ARPs, MHG, and now the problem. I just can't help but think that it has something to do with the work I have done.
 

Grimsta

Supramania Contributor
May 30, 2007
1,081
0
0
Santa Rosa, Ca.
Yes... interesting. Well to do that head work they had to take off some piping right? Check for a boost leak. Check the couplers for tears, or even the vacuum line for the boost gauge that tees behind the intake manifold.
 

thebuddrik

New Member
Jun 2, 2007
149
0
0
45
Lafayette ,La.
ok guys, i tested the air gap and i have a few questions, the CPS was in the car and i saw three pickups up in there, LOL, which one matters? if the cps is in the car they have the top one (.007) the front one on the wheel with all of the teeth (.015) and the bottom one (.016). i also noticed that the CPS was kind of far to one side of the adjustment. i would have pulled it and moved it one tooth but i dont have my timing gun. (timing was set at 10 when it was reassembled) anyway, what contact is consired the "air gap"?
thanks
 

thebuddrik

New Member
Jun 2, 2007
149
0
0
45
Lafayette ,La.
Grimsta;1020689 said:
Take the filter off and take a pic of the honeycomb on the inside for me. It does look alright but it could be covering up part of the honeycomb

grimsta was right, the rubber gasket for the adapter was covering the mesh by about 3/16 of an inch on each side. it was like that before, i had seen it before, i guess now that the head is clean and fresh it is pulling harder than before. now when the turbo spools the head flows better and when the AFM was restrected a little it caused the velosity of the intake air to speed up. at least that is all that i can figure out. i trimed the excess off and now she runs good. there is still a small miss at lower rpms. can that be caused by my plugs being gapped at 28 insted of 31?
thanks guys
 

Grimsta

Supramania Contributor
May 30, 2007
1,081
0
0
Santa Rosa, Ca.
I think you need the Weapon R CAI ;)

J/K, does this low RPM miss happen during boost or just driving? Pull the intake off and check the compressor wheel
 

arz

Arizona Performance
Nov 14, 2005
955
0
0
Mesa, AZ
www.ArizonaPerformance.com
annoyingrob;1018766 said:
IIRC, electrical resistance goes up exponentially as the gap increases.
A spark event becomes exponentially much less stable as the pressure goes up. Closing the gap makes the event much more likely. As the pressure goes up colder plugs will be required.

Pardon my late response, I hit submit and noticed 5 pages, this was from the first page.
 
Last edited:

Grimsta

Supramania Contributor
May 30, 2007
1,081
0
0
Santa Rosa, Ca.
If you have a couple chips in your compressor wheel thats probably it. I had a wheel with just a little bent edge on 2 fins, very very minor, and the thing would buck intermittently
 

thebuddrik

New Member
Jun 2, 2007
149
0
0
45
Lafayette ,La.
I think I found the problem. The CPS is reading over 240 ohms on each or the three coils. I called Champ. Toyota and they want $436.73 for a new one (he said that retails at $600, SOGI discount is the BOMB!). Call me cheap but that is still too much for me arter all that I have spent so far. I guess that I am looking for a used one.
 

Grimsta

Supramania Contributor
May 30, 2007
1,081
0
0
Santa Rosa, Ca.
Ha ha, what do you know, I have a used one, lol.

I thought my cam sensor was bad alittle while ago so I bought one from a guy on Craigslist for $80. Turns out it wasnt the cam sensor. So I can get you this one for $95 shipped