MAF code 33??? - Page 2

Blue Bowtie · #16 05-19-2007, 12:58 PM

All good information. If you are still using the 305 calibration, the "33" is almost a guaranty. If the "33" sets with a 350 PROM, verify that the TPS voltage is at least 0.48 VDC, and preferably closer to the 0.61 VDC limit.

If all that fails, a custom program may be the only way to remedy it. Despite common advice, AVOID using an ARAP-based BCC as a start point for programming. The MAF tables in the ARAP and ARAR code aer very good, but the timing is way too advanced to be practical for a daily driver.

Morley · #17 05-19-2007, 01:27 PM

Quote:

Originally Posted by Blue Bowtie

AVOID using an ARAP-based BCC as a start point for programming. The MAF tables in the ARAP and ARAR code aer very good, but the timing is way too advanced to be practical for a daily driver.

I would have to disagree on this point. I used ARAP for my base programming and was even able to advance the timing a bit further in some places within the tables. My car is a "DD" and has no detonation issues, even using mid grade gas.

iroc343 · #18 05-22-2007, 07:49 AM

Morley, thanks for all the info. I changed the knock sensor, the electronic spark control module and fussed with the female connectors on the MAF plug--- problem still there. You mention changing the prom and the carrier. The prom is a Hypertech unit for the 350, although it's for an automatic trans. Could that be a problem? You also mentioned a carrier in the ECM, is that something separate from the prom? I'm about at my wit's end here. I have thrown all kinds of money and time at this and can't seem to come up with a fix.

Morley · #19 05-23-2007, 01:44 AM

The "carrier" is also called a Calpack or Memcal. The PROM chip is actually a part of this unit. The entire problem may be coming from the hypertec unit. I personally don't like them and won't use them.
As an iterim fix, set your TPS voltage to .65 and see if this clears up your problem. If it does, then it is the calibration on the hypertec PROM chip.

iroc343 · #20 05-23-2007, 08:54 PM

Morley, you may have put me on to something. Tonight I exchanged the hypertech chip for the oem chip and the problem seems to have gone away. I put about 30 miles on the car and no service engine soon light. I am considering having a custom prom made for the exact application by a company called Motorvation. Anyone familiar with their work?

Morley · #21 05-23-2007, 11:19 PM

Quote:

Originally Posted by iroc343

Morley, you may have put me on to something. Tonight I exchanged the hypertech chip for the oem chip and the problem seems to have gone away. I put about 30 miles on the car and no service engine soon light. I am considering having a custom prom made for the exact application by a company called Motorvation. Anyone familiar with their work?

Hypertec, A.K.A. hypercrap's chips have been known to cause false code 33's in MAF based TPI's...they just plain suck.

How much does motorvation want for their "chip"? Never heard of them 'till now.
If you post a picture of the hypercrap memcal I might be able to tell you if I can reprogram it. If not, go look at moates.net for his G1 adaptor ($35) and see if you can come up with an EERPOM like these http://cgi.ebay.com/2-x-ATMEL-29C256...QQcmdZViewItem I can burn the prom chips for whatever you need.

iroc343 · #22 05-24-2007, 08:15 AM

Spoke too soon. Did it three times in the 13 mile drive to work this morning. Seems to be worse in cool air. Motorvation is asking $389 for their chip. They have a form to fill out that seems to cover all the bases as far as parameters go.

Morley · #23 05-24-2007, 10:26 PM

Quote:

Originally Posted by iroc343

Spoke too soon. Did it three times in the 13 mile drive to work this morning. Seems to be worse in cool air. Motorvation is asking $389 for their chip. They have a form to fill out that seems to cover all the bases as far as parameters go.

That's quite pricy for what you apear to need. You're just looking for a stock calibration, correct?

iroc343 · #24 05-25-2007, 07:28 AM

Morley, I would like to take full advantage of what the chip can offer as far as performance enhancements. I have set the TPS to .65 as you suggested and so far it's running good with no ses light. What does that do, put the ecm into a different mode? I appreciate your offer to help with the programming, but I wouldn't want to burden you with my problem.

Morley · #25 05-25-2007, 11:15 AM

Quote:

Originally Posted by iroc343

Morley, I would like to take full advantage of what the chip can offer as far as performance enhancements. I have set the TPS to .65 as you suggested and so far it's running good with no ses light. What does that do, put the ecm into a different mode? I appreciate your offer to help with the programming, but I wouldn't want to burden you with my problem.

You are basically lying to the ECM when you set the TPS to a higher voltage. When it sees the TPS voltage at .54 it "knows" the throttle is at idle. And when at idle the MAF should read a specific voltage (related to air flow in grms/sec). Now, your problem was that it was seeing a higher voltage on the MAF at idle than it is supposed to see and sets the code 33 fault. By raising the voltage to .65 at idle the ECM thinks you are just off of idle and the higher MAF reading is now within acceptable parameters for the ECM.

As far as the programming, no problem. I don't like to see people spend that much just to get a basically stock calibration. If you were to have lots of parameter changes for things like cam change, heads, intake, etc., the price they charge isn't bad (assuming they get it right). But for a stock calibration with a few flags flipped (ie VATS turned off, speed limiter turned off, injector size changed) that price is just too high.

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