BlackBoulder

Alright, so i finally got the dreaded code 13 out of the way. Now im stuck with code 34, (low voltage indicating high vacuum) replaced the burnoff relay and that didnt do anything. The previous owner told me he recently replaced the MAF, i don't know if it was used/remanufactured or not. But what i did notice is once i unplugged the connector.... Nothing happened. The engine stayed running the same as it did while plugged in. Could this possibly be a connector issue? This code is driving me nuts. Any help is appreciated!
-Respectfully, BlackBoulder

Tuned Performance

iTrader: (92)

http://chevythunder.com/maf_code_34.htm
I think your mistakes it's low engine vacuum low voltage /grams per second reading.
Code 34- This indicates a faulty maf or map sensor, depending on your tpi system. MAF: This code is se when the ecm sees the following conditions: airflow less than 2.5 gps, engine speed of 600 rpm or greater and the tps is above 6% angle. The typical problems are usually false air, vacuum leaks, or residue build up on the maf element or behind the throttle plates. Check the wiring and connectors very carefully, especially if this code is also present with a code 33 and 36. MAP: This is set when the ecm sees a indicated low air flow, or in other words a unrealistic high manifold pressure. Usually a bad map sensor is at fault, but check the wiring and connectors for shorts.

BlackBoulder

Thanks for the reply, i checked the wiring from maf, everything looks to be in order. Havent check the map sensor wires yet though. I will do that tomorrow before work. And the vehicle idles normally around the 10rpm range sometimes flutters to 15 but then back down to the 10ish area once its warmed up.
On a cold start it idles at 15 and when i give it gas it hesitates for a second or two then revs up. I can slowly press the gas pedal down and it will rev up just fine. Once it warms up after 5 or 10 minutes it runs just fine. Its also died on me a couple times while putting it into reverse from drive. But starts back up no problem.
-BlackBoulder

Tuned Performance

iTrader: (92)

It could be the iaccausing the rpm fluctuation map wires ?
I thought you have a maf !

BlackBoulder

I do have a maf, im not entirely sure if i have a map. People have said some do and some dont. I tried locating a map sensor on my 5.0TPI and i cant find it. The tunerpro software says code 34, maf burnoff. I replaced what i thought was the burnoff relay with no luck. This issue is driving me nuts.
-BlackBoulder

jermdm

I'm also fighting this same code. If you have a MAF, you wont have a MAP and vice versa. Code 34 is MAF low air flow detected and not something to do with the MAF burn off. I'm thinking my issue is a bad ECM. I can start my car when its cold and sometimes its fine and other times it stumbles some and eventually starts running fine. Other times, I will start it and its fine and after a minute or more or less, it stalls out like you turned off the ignition. It will start back up and stall right out 2 or 3 times or more then start right up and run fine like nothing happened. I have a rough idle at times and other times, it runs nice and smooth. I've had the CEL come on after starting it and it goes out by itself after about 30 seconds or less. Only code is a 34. I replaced the MAF with a reman acdelco with no change. Swapped it out with another since it was still under warranty and still the same thing, so I know it not the sensor itself. 3 sensors doing the same thing can rule out the sensor. Replaced the MAF connector with no change. With it being an intermittent problem, I'm thinking its the ECM since it runs fine most of the time and sometimes has the problem. With it running fine most of the time, I can basically rule out the wiring and MAF relay but would still like to test these to completely rule those out. Also, don't worry about the burn off relay on your car. It wont have anything to do with your problem. The burn off relay is only active after the engine is shut off. This has no effect on how the engine runs. If you have a burn off problem, you will get a code 36.

BlackBoulder

Awesome, thanks for the info!
My Z will start up no problem, then stumble when i give it gas. After a couple of minutes of idling it runs just fine. The code says MAP sensor circuit error (Signal Low indicating high vacuum) but my tunerpro program says it is a Maf burnoff.

KyleF

Old thread, but here I am with the same symptoms you have. What was your resolution?

burnout88

Common cause of code 34 is leaking fuel injectors. Check your fuel pressure at the rail and see if the pressure bleeds down to zero quickly after shutting the car off. If it does that is your code 34. Have seen this many times.

KyleF

How does a leaking fuel injector cause an issue in the voltage read at the MAF compared to the TPS?

I am well aware of the issues associated with age on the injectors on the TPI, but this is the first I have heard of it being a cause related to the MAF circuit. So, I am curious how this relates. I would think I would be getting 02 codes for being too rich versus the MAF/TPS data.