MAF code 34 Low Airflow (low signal voltage)
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Joined: Jul 1999
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From: New York City
Car: 1986 IROC
Engine: 355 Tpi
Transmission: 700r4
Axle/Gears: 9 Bolt 3.27
MAF code 34 Low Airflow (low signal voltage)
I need some help, I have an 86 IROC 305 TPI with a code 34 that won't go away, I checked all hoses and the plenum, intake hose etc for leaks, I replaced the MAF and the relay checked for shorts but it still keeps coming back, Any help would be much appreciated
thanks
thanks
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Joined: Jan 2000
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Likes: 309
IROC,
A '34' means low flow or low signal, indicating low flow. Check the electrical connectors at the MAF and both MAF relays. Check the connections at the ECM by removing and reseating the edge connectors. Verify a good ground at the ECM and all body/chassis/engine grounding points.
You could also have a low flow indication caused by a leak in the intake ducts and hoses (that you've apparently already checked), and especially the seams of the plastic air box infront of the throttle body.
Another possible cause is a TPS sensor adjusted too high (over 0.61VDC), causing the ECM to expect more air flow. The high base TPS also includes an incorrectly adjusted minimum air position of the throttle plates.
Any openings in the sealed crankcase ventillation system, like a chromed breather cap instead of the factory oil filler plug, can cause the error code. Any vacuum leak can contribute to the problem, and this includes a failing power brake booster.
You may also want to check the PROM. There was a TSB issued for '86 TPIs regarding faulty programming in the original ECM PROMs delivered with the vehicles. For more information on this, see http://members.aol.com/mmmm999/3rd-degree/index.html . Enter the site, click "TIPS", then select "Replacing Bugged PROM".
Failing any of those, you may have a defective replacement MAF, especially if it was a "remanufactured" unit instead of a new replacement.
------------------
Later,
Vader
------------------
"Make Me Bad"
Adobe Acrobat Reader 4.0
A '34' means low flow or low signal, indicating low flow. Check the electrical connectors at the MAF and both MAF relays. Check the connections at the ECM by removing and reseating the edge connectors. Verify a good ground at the ECM and all body/chassis/engine grounding points.
You could also have a low flow indication caused by a leak in the intake ducts and hoses (that you've apparently already checked), and especially the seams of the plastic air box infront of the throttle body.
Another possible cause is a TPS sensor adjusted too high (over 0.61VDC), causing the ECM to expect more air flow. The high base TPS also includes an incorrectly adjusted minimum air position of the throttle plates.
Any openings in the sealed crankcase ventillation system, like a chromed breather cap instead of the factory oil filler plug, can cause the error code. Any vacuum leak can contribute to the problem, and this includes a failing power brake booster.
You may also want to check the PROM. There was a TSB issued for '86 TPIs regarding faulty programming in the original ECM PROMs delivered with the vehicles. For more information on this, see http://members.aol.com/mmmm999/3rd-degree/index.html . Enter the site, click "TIPS", then select "Replacing Bugged PROM".
Failing any of those, you may have a defective replacement MAF, especially if it was a "remanufactured" unit instead of a new replacement.
------------------
Later,
Vader
------------------
"Make Me Bad"
Adobe Acrobat Reader 4.0
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