dasferret

I have a dead stock 92 camaro RS and did the ultimate TBI mods in a spare TB I had laing around. I smothed the entire top of it and spaced the injectors up with 1/4" long peices of hard tubing. I put this on my car and it gave me a code 33 and when I gave it 2/3 throttle or more it was running lean. After adjusting everything and testing all sensors, I gave up and put the stock unit back on. Started the car and everything was perfectly fine. What could be the problem here? If need I might be able to get pics and can def give casting numbers on the TB's.

rough

Did you make your fuel pressure regulator adjustable ?

dwillis

iTrader: (6)

is your pod spaced too high letting the fuel get on top of the tbi instead of spraying down into the tbi.and is it a 305 or a 350 pod?check those things out.also check for vacuum leaks..
oh yeah "Been there done that"

dctrumpet

iTrader: (10)

Please correct me if I am wrong, but I think code 33 usually means that the MAP sensor voltage is too high (low vacuum) for 5 seconds when throttle opening is less than 4%.

CIRCUIT DESCRIPTION :

The Manifold Absolute Pressure (MAP) sensor responds to changes in manifold pressure (vacuum). The ECM receives this information as a signal voltage that will vary from about 4.5 - 4.8 volts at idle to 4.0 - 4.5 volts at wide open throttle. The "Scan" tool displays manifold pressure in volts. Low pressure (high vacuum) reads a low voltage while a high pressure (low vacuum) reads a high voltage. If the MAP sensor fails, the ECM will substitute a fixed value and use the throttle position sensor (TPS) to control fuel delivery.

TEST DESCRIPTION : The numbers below refer to circled numbers on the diagnostic chart.

1. A Code 33 will set when:

1. MAP sensor signal is too high, (pressure greater than 68 kPa (10.0 psi) or less than 9.0 inches of Hg.), for a time greater than 5 seconds.
2. TPS less than 4%.
3. Engine misfire or a low unstable idle may set a Code 33. Disconnect MAP sensor and the system will go into backup mode. If a misfire condition remains. See: Related Tests and Information

2. If the ECM recognizes the low MAP signal, the ECM and wiring are OK.

DIAGNOSTIC AIDS :

1. With the ignition "ON" and the engine not running, the manifold pressure is equal to atmospheric pressure and the signal voltage will be high. This information is used by the ECM as an indication of vehicle altitude and is referred to as BARO. A comparison of this BARO reading, with a known good vehicle with the same sensor, is a good way to check the accuracy of the problem sensor. BARO readings should be similar within +/- 0.4 volts.
2. A Code 33 will result if circuit 455 is open.
3. See: Symptom Related Diagnostic Procedures\A - E Charts & Related Test Procedures\C Charts\Chart C-1D Manifold Absolute Pressure (MAP) Output Check to test the MAP sensor.
4. If a Code 33 is intermittent, See: Symptom Related Diagnostic Procedures\Intermittent Condition

dctrumpet

iTrader: (10)

Hope this helps!

dctrumpet

iTrader: (10)

Check TPS, IAC on the TBI that caused the issues and just a quick thought... Was the vacuum line to the back of the TBI (MAP sensor port) connected well with the newer TBI?

Hope this helps you out.

dasferret

Didn't make fuel pressure reg adjustable, injector pod was stock unit off car and was reason I didn't make it adjustable cuz I didn't have another that would work. All lines where connected and checked, double checked and triple checked all other items. In fact used all items off the modded TBI on original one and with no adjustments car ran fine. Only thing I can think of is that the pod was too high.

rough

Got the same exact problem now lol. Modified my TBI and now its running like crap. Id say about 30% of my power is magicaly gone. Didnt see no fuel up top, but would adding that spacer to the pod do this ? My car is also more quiet now, its not as loud, shifts harder for some reason, but acts realy weak and the rpms dont go up fast like before, they kinda just hang like its burning out but its not.