l36TB to l67TB ISSUES

**01gpgt01** · 08-31-2010

Went from a l36 TB to a l67 TB. I reused all the l36tb's sensors. The car runs great. on my tune the only changes I made was to drop 2 degrees of timing so id be safe doing a WOT pull and getting a baseline on fueling. Injector Duty Cycle was 98percent(GTP injectors) and maf hit 10,680Hz before the tb After the TB maf only hits 10,100 and IDC hits 79 percent.

did I do wrong. TPS reads 100percent. Its to dark out to check to see if the blade is 100 percent open. I had no knock

**01gpgt01** · 08-31-2010

Just went outside and checked. Before I installed the TB I checked to see if the blade opened 100 percent. It did when the bracket hit the stop. pushing the throttle pedal the cable bracket hits the stop. So obviously it opening up the whole way

**01gpgt01** · 08-31-2010

Got my answer..Thanks I was being stupid. I need a l67Maf bin

**FoSHO99** · 08-31-2010

what year of sensors were you swapping?

**matt5112** · 08-31-2010

Ummm yeah.... I was going to say you need a new maf tune as well.

Any time you touch your TB/intake its new MAF tune.

**01gpgt01** · 08-31-2010

I used my 2001's l36 sensors. Im pretty sure they are exactly the same. I tried to flash over a GTP maf bin but im still getting low maf Hz 9,900-10100 and low IDC. Im sure its leaning like a Biatch

**matt5112** · 09-01-2010

Im sorry but shouldnt the frequency be lower since the air has a larger throttle plate to flow by?

The MAF reads what hits it, not the total of whats in there.

For a given volume of air moving, the larger diameter of TB, the less dense it has to be to maintain that speed.

The lb/m readings should be the same, but thats calculated based on the tables the PCM has and the MAF frequency.

The MAF frequency is the output of the MAF, it hasn't been converted to a meaningful unit until it hits the PCM and you get that lb/m figure.

By that logic, i'd say its a good thing its lower. but the IDC is not good.... The MAF tables from what i understand control fueling so you might want to check your fueling at your new lower peak MAF Hz.

This is where a wideband is helpful.

**01gpgt01** · 09-01-2010

Yep your dead on. I got it figured out with help from you all and PRJ on the other forum. Thanks. Basically the curve of my maf moved to a lower HZ. Ive adjust the fueling via droping in a GTP bin on the maf and made adjustments there. Sofar so good. I must say at part throttle the trans shifts much smoother and doesnt bog down. That POS l36 Tb was choking the engine. Ive just about dialed in the WOT trims and 02's. Just ordered a WB. SO its all good in the hood for now