Im not going to give the saga on my issue, unless asked...

Im looking for any and all of peoples solutions to code 33.

mabee this could become a part of one of the FAQ stickys, i know im not the only one having/had this issue.

much appreciated replys!

~JaSoN

 

Sounds like a bad maf burnoff/power relay

 

both have been replaced with known good units.

Thanks for the info, keep it coming!

~JaSoN

 

bump

 

I had a problem with my connector and it was setting a code 33. one of the wires on the terminal was getting pushed back. PITA

 

Thanks for the info!

I checked mine, all the terminals looked o.k., but i used a pick and slightly adjusted them just to make sure. problem is still there though.

keep the solutions/info coming!

~JaSoN

 

Do you have a wiring diagram? Verify that the wires are doing what they are supposed to. Check continuity, etc. I had a wire go bad to my coil, the car would just quit, randomly. Found out that a wire had broken internally, looked just fine, but, if I wiggled it while testing, it would lose the connection.

 

Yes, i have a dealer service manual. ive been through the flow chart, shaken all the harnessing.
Thanks for the info!

~JaSoN

 

What is the TPS voltage at the closed throttle position?

 

.54 volts, with it pointing forward and up as possible.
I made this adjustment about two seasons ago, and have recently checked it.
-Before the adjustment; Code 33 every 5 miles (aproximate)
-after the adjustment; code 33 every 50-200 miles (aproximate)

~JaSoN

 

An engine misfire or low unstable idle may set off a code 33. Is this a factory motor with factory cam?

 

Well,
Its the original engine,
with flat top pistons, .030 bored, a comp tpi roller cam.
I noticed code-33 once in the short time before taking the engine from its completely stock form. The owner before me also stated "yea that happens every once and a while".
It does surge a little at idle, no misfire.

The code always activates at 1800-2000 rpm when cruizing at light throttle.

Great question!

~JaSoN

 

You can try to increase the TPS voltage to about 0.60V to see if that cures it.

 

Sounds like it could be a faulty map sensor. Common on SD systems.

 

So, what car do you have?

And what mods?

 

My assumption was that it's an '87 (given the username), which would make it either a TPI or L69 carbed engine. Also, his early post has a signature reading " 5.0's... both types" which would imply that it WAS a 305 until we learned later that it has been bore +0.030". My conclusion would be that it is an '87 TPI 310 CID with flat tops and a "Comp TPI cam". We could further presume that it has stock heads and may be flowing a bit better than the original 305 due to the cam (improved VE). That assumption, coupled with the fact that the extra few cubes are likely pushing the intake flow at a given RPM and TPS beyond the limits of the stock MAF tables.

That's a lot of assumption, and we all know what happens when we assume...

I was hoping that "cheating" the TPS voltage upward would get the MAF reading back into acceptable range as a temporary fix. Of course, the proper repair would be to program it correctly, including correct MAP tables, correcting the displacement, adjusting the injector constant for the extra cubes (and potentially the use of 10% ethanol), and improving upon all the rest of the factory oversights with the $32B code.

So, what exactly DO you have?

 

Thats some fine educated guessing

1987 formula 350
-350 tpi
-rebuilt in engines class (baron institute of technology,windsor, CT)
-professionally bored .030 over/cleaned/checked for cracks (RAD machening)
-bronze valve guides
-swirl polished stock sized valves, 3 angle cut seats
-umbrella seals on both intake and exhaust
-comp cams (part #???)
-double roller timing chain, set to 0 degrees advance
-polished crank
-sealed power hyperutectic pistons (part#???)
-new crank/rod bearings
-milodon high flow water pump
-edelbrock TES headers/y pipe (emissions legal)
-flowmaster cat back
-melling high volume oil pump
-stock replacement egr valve
-Timing set to 15 degrees initial(with connector disconnected)
-MSD 21 lb. injectors
-some pos adjustible fuel pressure regulator (47 psi or so right now)
-new mass airflow sensor
-air pump seized, so "removed"/ a/c "removed"
*anything major not listed is stock/stock replacement( intake, ect...)*
-4l60 "700r4"
-Rebuilt in transmissions class (BIT)
-rabestus clutches and steels
-all seals replaced
-B&M's first level shift kit
-Rebuilt pump
-Borg Warner 9 bolt
-3.27 factory gear set
-Factor cone style limited slip that doesent limit slip so well anymore

-Have had both a "SUPER CHIP" and the factory chip in the car, currently have the "SUPER CHIP"

-ill get back to you on the cam/piston #'s... its been a few years


I think you've got a good theory there, ill try setting the voltage to .60v when once all the salt washes away and i start driving the car for the season again. i wish i knew someone with a chassis dyno and the equipment/knowledge to set up an "optimal" chip.

Thanks,
JaSoN

p.s. Its been so long (2003) i dont remember what my theory was about my signature... i think it had to do with mustangs and police???

 

Mine goes off on rainy days with K&N's in. I put some cheapo fram filters in and it stopped, didn't feel any performance difference either.
I could also suggest just checking the whole maf system's wires to make sure they are snug.

Hope you fix it!

 

thats an interesting solution, im still using the factory formula airbox/ purolator filter.

o.k. heres the cam spec's:

comp roller hydrolic(listed to be designed for stock tpi engines)

duration intake:264/exhaust:269
valve lift intake:.488/Exhaust:.495
Lobe separation: 112

Thanks for your solution!,
~JaSoN

 

The car is back as my daily driver.

-code 33 at least once everytime i drive it.
-tried moving tps to .60 volts, code 33 everytime i drive it still.
-once its warmed up, or i keep the rpms away from 1800-2000 it doesent set off nearly as much.

the car runs great untill it goes into limp mode.

i wish i could just "adjust" the perameters in the chip...

im getting really sick of shutting the car off for 30 sec, coasting in nutral or sitiing at a light. i live in a moderate traffic city.

just figured id update...

~JaSoN

 

K I've delt with this problem to. I havent completly solved it because its happenes once a month or so. but i started with removing the wire wrap from the wires on the maf sensor and found they had rubbed together. but when i took a multimeter to the harness everything had checked ok even though i had bare wire showing through. make sure to seperate the wires and repair where needed. I also spliced on a new connector from napa for good measure. But I believe our problems may be related because i have a 350 using a 305 chip. I also have a copy of a vette chip that will balance things out but it raises my idle to the 1200 rpm range. My theory is I need to us the timing table from my stock chip and the rest from the L98 vette code. but that involves me buying a pocket programmer. and they raised the price to 170 for one of those.

 

I had this exact identicle problem you're describing. I had to check and make sure this wasn't my post the symptoms are so exact.

Here's the solution. Go to moates.net and get yourself the gear to program your own chip. Until the gear arrives, spend as much time as you can in the DIY prom forum. Once the gear gets here, load up a chip with $6E code (ARAP) and don't forget to disable VATS! Start with that and you'll notice an immediate difference. I did. On top of that, do some fine tuning and you'll be happy as pie.

I remember running $32 code. It was like night and day changing to $6E and further tuning is a snap.

Code 33 is set because the computer doesn't see the proper amount of airflow at such a low rpm 1800-2000 rpm. The only way to correct it is to fix the maf tables. Just going to $6E code fixed it for me, but my mileage was crap until I tuned the timing and fuel delivery. Now it runs like a champ.

Spend the money on the gear, it's worth every penny and is not that expensive considering the amount of parts you could replace to chase this problem down. And get rid of that superchip. Ick.

-HD

 

I don't mean to hijack the thread, but I thought I would throw this question in here since it is relevant.

If code 33 is caused by the larger air flow, am I running the same risk when I finish putting my new heads (RHS 180cc) and 1.6 rockers on, given I have already done the cam (500 lift with the 1.6 rockers)?

 

Is your chip tuned to handle the 500 lift cam?

 

Its a standard chip.

 

All you have to do is change the maf voltage setting in the constants table in the chip, stock is like 35, mine is set at 75, and I'm pulling way more air than you guys. The only time I see code 33 is when I set my tps sensor over .60 volts at idle.

 

I had the tech 1 "scan tool" hooked up, and i noticed that the computer is seeing 5.2 grams per second with key on engine off... is this normal??? any one else have a tpi and a scan tool?

Thanks,
~JaSoN

 

Yes, that is normal. Mine is 13.4 grams key on/engine off, but I have a wells maf and homemade cold air.