Hi guys,
I have a 1999 Chevrolet Blazer LS, 4x4, v6, all that. For a long time now, it's had this problem where for a time after I start the vehicle, it's really hard to accelerate. I'll try to explain this as best I can... It doesn't happen every time, only about 50% of the time. What happens is when I put it in drive I can only push the pedal in a very small amount otherwise it bogs down like crazy and sometimes I can hear a pop or two come from the engine area. The check engine light has never come on. The thing is, as soon as I can get the RPMs high enough for the vehicle to shift into 2nd, all is well for the remainder of the trip. Even coming to stops and going again. This ONLY happens right after the vehicle is started. Any ideas? I'm baffled myself. It's not an extremely big deal because the vehicle is still driveable, and in fact it has been doing this exact thing for over a year (though it is getting more frequent). Also, I have tried putting the vehicle in neutral immediately after starting and it revs just fine, but when put into drive it bogs down when the pedal is pushed in more than a VERY small amount.

 

Sean I'm glad to see I am not the only one with this problem. My 2000 Blazer with the V-6 does the exact same thing. Mine is doing it more after it runs for a bit and shut off at a store then restarted it will bog down and miss almost as if it is running out of fuel. Just like yours after less then a minute it runs like a raped rabbit. Just getting ti to run like that takes a minute.

I was told by someone that is a certified mechanic that it could be the throttle position sensor or the fuel pressure regulator. How ever I have not tried to change either one yet until I come up with a for sure answer.

Lets hope someone on the forum with more knowledge has an answer for us.

 

So, I've stumbled upon something. The user from This forum: 1999 Silverado 5.3L bog down after startup - GM Inside News Forum has the same problem with his Silverado, and apparently, GM put out a service bulletin about this exact problem (Bulletin No.: 01-06-04-006) which you can read further down the page. HOWEVER. I have reason to believe that GM may have put out a similar bulletin about the Blazer due to what I saw on this page: Service Bulletin 12031 for Gmc ENGINE AND ENGINE COOLING | AutoMD The TSB is for a 2001 but surely it applies? It's the same generation, no?

 

So I found that TSB's can be found on http://www-odi.nhtsa.dot.gov/tsbs. The specific TSB mentioned above is here: http://www-odi.nhtsa.dot.gov/cars/pr...5&type=VEHICLE

 

This apparently doesn't apply to me, but may help you, bob.

 

And i thaught i was the only one having this problem. i can not seem to come up with an answer for it either...

 

More news, the user on this forum Lack of power first minute after startup. - Car Forums and Automotive Chat seemed to fix his problem with a new Mass Air Flow sensor.

 

Hey, forum newbie here...
I've been having a very similar problem with my 2001 4.3 4wd Jimmy (compounded with other problems too...)
Have you guys made any headway with this?
I am experiencing about the same thing right now, starts fine but trying to accelerate (about half the time, even after i've been driving for a bit) is real bogged down.
Even more common other times it will seem to accelerate fine, but will rev VERY loudly & not shift till about 500rpms past normal shift points.
Like I said above, i've had other problems as well. It all started with a P0300 which was finally fixed with a new fuel pump(?!) but of course not until after already replacing the plugs, distributor, upgrading to EFI & a new TPS.

Sorry, if I seem to be hi-jacking your thread, but hopefully some of what I already did can help you eliminate a few things & maybe someone will have a light bulb moment on my problems too :-D

 

I'm almost positive that my particular problem is with the MAF sensor. I'll be replacing it on either Wednesday or Thursday (I'm on vacation right now) and I will let you all know how that goes. @renesisspeed, I'm not sure what your problem could be, but if I was you, I would try and get the computer flashed. If I recall, the computer is what tells a vehicle to shift in an automatic vehicle. Mine will do that upon occasion, but usually only when I am stomping the throttle and giving it way more gas than is typically necessary. Good luck! (Btw I am by no means a mechanic so you'll probably want to get advice from someone who actually knows what they are talking about lol)

 

Look forward to seeing what your results are.
The ecm *should* have been flashed when it was upgraded to EFI, so I doubt that will do it, esp since it did this before as well.
Did a little tinkering over my lunch break & unplugged the MAF & took it for a spin. It seemed to accelerate better, although a 10 minute drive isn't the best measure. I'm going to cruise it a bit more later & see what it does. Thanks for the idea X-D
Ohh and: http://www.partswebsite.com/gmpartsc...n=3&type=parts

If i wind up needing one, you seen a better price?

Edit: Nope, still doing it.