Margo Gant

I have been having problems with my 2005 trailblazer. A few months ago it would turn over and not start replaced the relay seemed like it was starting fine. My daughter starting driving it as a daily drive and it would start then when she would come out to restart the car after work it would not start unless you pulled the relay and put it back into the car. It continues to do this it only stops working after it has been driven I took it to a mechanic and they couldn’t get it to replicate it but of course the didn’t drive it. I am at a loss as to what to try next? We did replace the map sensor at the same time

oilcanhenry

Can you post any OBD II codes?

Margo Gant

I hopeful am gonna get ahold of a scan tool tonight the check engine light has been going off and on

Margo Gant

It is throwing a P 0106

kevinkpk

I'd suggest after reading your last post, replace the vacuum tubing to the map sensor. I wouldn't think that that would cause the issue you are having, but one less thing to troubleshoot if that's not it.

Margo Gant

I have looked for holes in the tubing replaced the throttle body and still having the same issues I am ready to 😿

chem_man

I do not believe there is a vacuum line to the MAP sensor in a 2005 TrailBlazer. Here is a link on how to test a MAP sensor to see if it is working properly or not. If it is not, then I would replace it. They are about $40 - $45 dollars from rockauto.com

https://troubleshootmyvehicle.com/gm...sensor-tests-1

Good Luck!

Margo Gant

I purchased the map sensor off eBay for 12 bucks do you think buying a oem part might fix the issue?

chem_man

I generally do not trust ebay parts unless I know exactly what it is and can be reasonably assured that it is not a cheaply made part with little or no quality control. Considering that a decent, quality aftermarket brand MAP sensor (Standard Motor Products or Delphi) sells for right around $40 - $44 dollars on rockauto.com, I would be quite concerned about the quality of a $12 ebay MAP sensor.

Just as an FYI, ebay has become flooded with counterfeit ACDelco (and other OEM manufacturer's) parts and it is getting quite hard to tell the legitimate parts from the counterfeit parts.

Now, if you happened to stumble across a legitimate ACDelco retailer or a GM dealership parts department wanting to get rid of old ACDelco stock, then you got a great deal provided the part came in an ACDelco box and the MAP sensor has a GM or ACDelco sticker on it.

Just my two cents worth.

Good Luck!

oilcanhenry

A MAP sensor ( not a MAF sensor, CAN be cleaned, which takes more time than cleaning a MAF unit), but if it's gone I'd replace it with a GM unit. You'll likely NEVER have to touch it again, unless something damaged it in the first place, Use dielectric grease on all connections. It's cheap. It keeps water out. And it prevents corrosion.

As someone who spent many years off-road, on both four-wheel-drive vehicles and RACING, not riding, very fast and very powerful two-stroke dirt-bikes, often into deep water crossings which they were modified by myself for those conditions. The factory does NOT do a thorough job as YOU can do yourself.

I KNOW that dielectrical grease will keep your motor running when other's motors will die out, and you just keep on going on to the finish line, to collect your trophy.

And chicks absolutely _LOVE_ winners, so make sure you are ready to go on that front too! They'll be all over you, like there is no freaking tomorrow!