Please help out, I want to help out a friend, 305 vs 350 Eproms - Third Generation F-Body Message Boards

doc · 04-27-2003, 01:21 PM

What are the differences between a chip for a 305 and a 350?

Here is what I want to do. Andy has the 33 error code problem, he has done ALL of the ususal stuff, change out both relays, bought a new MAF sensor, checked all of the wiring, checked the pins. He can not get rid of the 33 code. I went thru the same bull$hit about 3 to 4 years ago. He is now only setting the code when he is under 2000rpm and the MAF is registering over 45gms/sec.

Andy has an '86 ECM ($32 def file) and I have an '87 ECM ($32b def file). I read his factory prom with my $32b mask from TunerCat and the constants table was all screwed up showing rediculous values. So I changed only the switch table (un Xed the 33 error code box and reburned the chip). This did not solve his problem because in the constant table threr is the flow value check value for the 33 error code which is set at 45gms/sec on stock chips. My chips have 255gms/sec for this parameter.

So I am going to burn him a chip using for a basis my 350 chip that NEVER gets the 33 error code.

Will a $32b chip work in his $32 ECM, in other words, are these backwards compatable? (for all 165 ECMs)????

Sorry about the length, and can anyone give some advice to help out a thirdgenner?

funstick · 04-27-2003, 02:07 PM

Quote:

Will a $32b chip work in his $32 ECM, in other words, are these backwards compatable? (for all 165 ECMs)????

yes.

and just set the injector constant.if your feeling fruity paste the sparl table.

doc · 04-27-2003, 03:07 PM

I have done two main things so far:

1) I have set the injector constant to 18.8#/hr.

2) Set fan on/off stuff and other constants to what is shown on my '87 350 Hypertech chip.

I have not look at any specific tables as yet.

Is there a cylinder size or eng size somewhere? I figured that that would be in the constants table if anywhere, and I did not see it.

Grim Reaper · 04-27-2003, 03:30 PM

Quote:

Originally posted by doc
Is there a cylinder size or eng size somewhere? I figured that that would be in the constants table if anywhere, and I did not see it.

Don't need to on a MAF car. The ECM only deals with the amount of air your moving into the engine to determine fueling. The size of your engine is unimportant for fueling. Only SD needs to know the cylinder size because it is a factor in the fueling of the engine.

Hope this hielsp.

RBob · 04-27-2003, 04:06 PM

Quote:

Originally posted by doc
What are the differences between a chip for a 305 and a 350?

Here is what I want to do. Andy has the 33 error code problem, he has done ALL of the ususal stuff, change out both relays, bought a new MAF sensor, checked all of the wiring, checked the pins. He can not get rid of the 33 code.

Code 33 is MAF too High Error. Someone in the past month posted the fix for this on the DFI board.

Basically the ECM thinks that the MAF airflow is too high for the RPM the engine is at. Find the malf code 33 diag parameters (in the BIN/cal) and set the MAF airflow trip point to a higher value.

That will get rid of the (false) error.

RBob.

doc · 04-27-2003, 05:09 PM

RBob,

There is a parameter in the constants table called
"MAF High Diagnostic (Error 33) Threshold".

It is set at 45gms/sec. This is the one that I changed to 255gms/sec and I have un-Xed out the Diagnostic code 33 box in the switch table.

I think that these two changes will get rid of the 33 error code for good.