Setting code 34 intermittently

[Jorge6.5]

My truck is setting code 34, from what I understand that has to do with the MAP sensor. The check engine light comes on every so often, just before the light comes on, the truck will buck as if the fuel was cut out for a moment. The light isn't always illuminated, will also go off during driving. The truck is a '90 Chevy k1500 305 tbi with 5 speed and is totally stock.

In the past few months the truck has gotten a new cap, rotor, plug wires, msd coil, PCV valve, air filter, fuel filter and coolant temp sensor in the intake manifold. All are ac delco parts except the wires and temp sensor.

I've had no luck finding any good info on this or how to go about fixing it. Could it simply be a bad MAP sensor or does the problem lie deeper?

Thanks for any and all suggestions.

 

[Dszx13]

Whoops. Confused map for mass air flow lol

 

[Dszx13]

My 93 had it pop up before. I changed it an I also had tps go out the same time. Changed both an never had a issue with it


Sent from my Ragged Out Z71

 

[95Escahoe]

Had the same on my 95 replaced it never had an issue since

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[Jorge6.5]

Both you guys replaced the MAP sensor and that fixed the problem? Sounds easy enough. I can see how mine could be bad, as far as I know it's the original one on my truck, 230,000+ miles now.

Any particular brand I should get? I prefer ac delco.

 

[Dszx13]

This was like 2-3 years ago when I had my issue. Don't remember the brand it prolly is original lol. Mine looked like it was. Had 293k on it


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[someotherguy]

Wow! Lots of miles on those, so not surprising the MAP could have actually been bad. In general though they tend to last the lifetime of the truck. Worth a try to replace it on a high mileage truck for sure. Go AC Delco or Delphi. But first, check its vacuum connection at the rear of the TBI. They connect with a plastic tube that has a rubber boot; the boot often hardens and cracks, or doesn't fit tightly anymore. You can replace it with regular vacuum line just be sure to route it so it won't kink.

Richard

 

[Dszx13]

Wow! Lots of miles on those, so not surprising the MAP could have actually been bad. In general though they tend to last the lifetime of the truck. Worth a try to replace it on a high mileage truck for sure. Go AC Delco or Delphi. But first, check its vacuum connection at the rear of the TBI. They connect with a plastic tube that has a rubber boot; the boot often hardens and cracks, or doesn't fit tightly anymore. You can replace it with regular vacuum line just be sure to route it so it won't kink.

Richard

Forgot about the line. Mine broke when I took the old map off. I used heat shrink on it. Lol. It worked like it should've


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[95Escahoe]

Both you guys replaced the MAP sensor and that fixed the problem? Sounds easy enough. I can see how mine could be bad, as far as I know it's the original one on my truck, 230,000+ miles now.

Any particular brand I should get? I prefer ac delco.

AC Delco, replaced the MAP sensor and that hard emission tubing and rubber boot (can get that at any auto parts store)

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[Jorge6.5]

The vacuum line and rubber end boots looked good last time I checked it. I'll check it again and might just go ahead and replace with rubber hose along with the map sensor.