On my 88 formula 305 tbi/auto my ses light has been coming on. I am running a code 34 constantly. From everything that i've read that is my map sensor, right?

My car takes long cranking to start usually 6 secs on first try with no start, then crank right again for about 3 secs, starts, dies and then starts right up again and runs a little rough at first then ok. It drives fine down the road, but seems to run a little rich.

Where should i start at? Does the Map have a relay to replace like the TPI cars with MAF?

Thanks, i have very little experience with TBi, brad keith

 

Yes 34 is a MAP code.

1st check the vacuum hose from the TB to the MAP sensor for leaks.

 

i too have an 88 firebird with tpi, where is the map sensor located? Thanks in advance.

Mike

 

Brent, i've already checked for leaks, broken hoses and such. nothing there.


Chevy8ford, your car with tpi has a mass air flow MAF sensor. I probably shouldn't write this because i am not knowledgeable about tpi, but the maf should be in front of your throttle body, in the air intake. hopefully someone can clear that up for us.

 

MY BAD, i must have been taken over by a demon for a sec, i have tbi, not TPI. WHOOPS. so where's that at?

thanks,
Mike

 

I thought on another post i read your sig and it said TBI, i was wondering.... MY car's MAP sensor is on the firewall, to the passenger side rear of the air-cleaner. Your's should be there too.

 

Code 34 is a MAP sensor low. Won't be a vacuum line problem. It is either the connector fell out, the MAP sensor is bad, the MAP wiring is bad, the ECM is bad, or the TPS is shorted.

With a scan tool check the TPS operation and the reported battery voltage. If both check out then move on to the MAP. If have another one try swapping, otherwise inspect the wiring.

The driving fine a little rich is interesting. The ECM is actually creating a MAP load value (default mode) with the TPS & RPM inputs. Alpha-N style.

RBob.

 

When my map sensor went bad, my idle would jump up and down pretty bad. Though I never got a code for it. I finally figured it out when I was using WinALDL and saw the sensor data.

 

My car does idle irracticly. jumps from around 1200 to down around 600 for no apparent reason. I have a hard time believing that the ecm is bad, or the tps is shorted? Not trying to be ignorant, but it's jus that it runs SO good other wise. If it had either one of these problems, wouldn't it be almost un-drivable? thanks, brad

I have full power in every power-range, but it smells rich and has a prolonged crank start. I'm going to tear into her tomorrow, once the snow melts and i get my salamander heater out! I've got a new map sensor, plugs, wires, cap/rotor, air filter, fuel filter, the whole deal to install tomorrow. I'll keep you updated.


And thanks for the information from you experienced car computer diagnostics gurus!!!!!!