Need help...Code 34
Thread Starter
Melting Slicks
Joined: Jan 2002
Posts: 2,531
Likes: 35
From: Lecanto Florida
Need help...Code 34
Problem: Intermediate "Check Engine" light when first starting up cold. Stays on and car runs in "limp" mode. After 5 minutes if I stop, turn off engine, wait a minute, restart, "check engine" light goes off and car runs fine for the rest of the day. Doesn't do this all the time..about 1/3 of the time I go out.
I have 130,000 miles. New cleaned K&N filter. Mobil 1 and filter every 3,000 miles.
Book says Code 34 "low voltage reading on MAP sensor". Other paperwork just says Mass Air Flow Sensor. Are they the same ?? Any suggestions on a fix?
Thanks.
I have 130,000 miles. New cleaned K&N filter. Mobil 1 and filter every 3,000 miles.
Book says Code 34 "low voltage reading on MAP sensor". Other paperwork just says Mass Air Flow Sensor. Are they the same ?? Any suggestions on a fix?
Thanks.
Le Mans Master
Joined: Feb 2000
Posts: 9,715
Likes: 27
From: Kempner Texas
Re: Need help...Code 34 (CREWZIN)
If your car is an 87, as your sig says, then you have a MAF sensor not a MAP sensor.
I don't know what year book you've been referencing but MAP is for Speed Density systems, which you don't have.
You have an intermittent problem which can be a little more difficult to track down than a hard failure is.
I'd first check that there are solid connections at the MAF sensor. It could be something a simple as a loose connection where the wiring harness connector plugs into the MAF.
There are a series of other tests that you can run on the MAF either using a digital volt meter or a MAF checking plug. Someone posted a link to the site that sells them; it was posted only a few days ago.
One trick is, with the engine idling, tap the MAF near the bottom with the handle of a screwdriver. If the engine stumbles, the MAF is bad.
Jake
I don't know what year book you've been referencing but MAP is for Speed Density systems, which you don't have.
You have an intermittent problem which can be a little more difficult to track down than a hard failure is.
I'd first check that there are solid connections at the MAF sensor. It could be something a simple as a loose connection where the wiring harness connector plugs into the MAF.
There are a series of other tests that you can run on the MAF either using a digital volt meter or a MAF checking plug. Someone posted a link to the site that sells them; it was posted only a few days ago.
One trick is, with the engine idling, tap the MAF near the bottom with the handle of a screwdriver. If the engine stumbles, the MAF is bad.
Jake
Team Owner
Joined: Sep 2001
Posts: 62,139
Likes: 1,728
From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
Re: Need help...Code 34 (CREWZIN)
Its a MAF code, no MAP for your year.
Try to test the MAF as suggested, if its failed, then you should also replace the 2 MAF relays behind the battery on the firewall.
Actually those can cause the code themselves, MAF codes 33 and 34 overlap somewhat.
Try to test the MAF as suggested, if its failed, then you should also replace the 2 MAF relays behind the battery on the firewall.
Actually those can cause the code themselves, MAF codes 33 and 34 overlap somewhat.
Thread Starter
Melting Slicks
Joined: Jan 2002
Posts: 2,531
Likes: 35
From: Lecanto Florida
Re: Need help...Code 34 (vader86)
OK thanks guys. I ran the car and hit the bottom of the MAF and it runs fine. I'll take the MAF off tomorrow and make sure the connections are tight. I did see a very thin strip part way hanging down from the bottom of the MAF. It looks almost like a thin rubber band, some sort of tiny gasket that runs around the square box that's attached to the underside of the MAF. Maybe that's letting in some air and causing a low voltage reading ??? Probably not. I found the two relays behind the battery and will order them tomorrow and replace them for the heck of it. The local Chevy dealer is our club sponsor and we get parts at cost plus 10% so they shouldn't be too much. Last but not least I'll change out the MAF itself and I know that expensive.
Drifting
Joined: Feb 2003
Posts: 1,976
Likes: 2
From: San Antonio Texas
Re: Need help...Code 34 (CREWZIN)
I just had this code come up... replaced the relays( A-Zone about $12 ea) and although I was sure that this was the problem, it didn't help. Did a "search, and found some one had fixed it with a new air-filter. This worked. In your case, you may have over-oiled your K&N; this can be a problem with getting oil on the sensors' wires. Clean and lightly re-oil your filter. The relay might burn off the oil, or, if you have removed the screens, you can clean the wires by spraying some carb-cleaner on a Q-tip, and very, very gently clean the wires. As stated above, check your wiring, contacts, and replace relays if they're old. Good luck.
:chevy
[Modified by Curveit, 5:28 AM 5/7/2004]
:chevy
[Modified by Curveit, 5:28 AM 5/7/2004]
Thread Starter
Melting Slicks
Joined: Jan 2002
Posts: 2,531
Likes: 35
From: Lecanto Florida
Re: Need help...Code 34 (Curveit)
OK...Took off the MAF and cleaned it up the best I could. I still have the screens in and by the looks of the wires inside, I really don't want to get near them. Took the K&N and cleaned and re-oiled it (lightly). Made sure all the connections are clean and tight. Managed to get both relays out (without taking out the battery = PITA) and went to the Chevy dealer and ordered a new pair ($9 ea.). They're in stock at the warehouse in Jacksonville so I'll get them on Monday and put them back in. Thanks for everyone's help and opinions and hopefully this will take care of the "check engine" light.
