I was waiting to hear back from you on the results of the cleaning.

To run the engine with the duct work off, simply unplug the MAF sensor.

 

ok finally ran the cleaner out of the tank. and i have already filled the truck up a couple of times. problem is. the damn problem is back. i don't care what the tranny guy said, i know there is a problem with something in the trans. my g/f's dad came over (previous owner of the truck) and we disconnected the battery to reset the computer. so i will see what happens. he also told me to get the transmission serviced. i work at autozone and we sell a valve body shift kit by B&M. does anyone think that maybe the valve body is throwing fits? here is a recap of what is going on, (the original complaint plus a couple of things) At 70-75 miles an hour the truck jerks a few times in the morning during my 10 mile commute on a major interstate. i get off the ramp and sit at the light. when it turns green, the truck seems to have a problem shifting from 1st to 2nd. it jerks about two or three times and then goes into second. sometimes no jerking and it will be a light shift or a hard shift.as with the other gears no jerking at all yet, but sometimes its a hard shift or a light one. when i am on the interstate or driving around it is starting to act like it does not want to shift down and sometimes i have to manually take it out of overdrive. when i first got the blazer when i got out of overdrive when you hit the pedal a bit more it would pin you in the seat. now i don't feel the torque/power. it seems to be a transmission problem right? now will a valve body shift kit help this? or should i look into a trans?oh and by the way. still not a peep from the check engine light. and it does work, it comes on during startup and turns off almost immediatly,and the code scanners (4 different ones) are all saying pass no codes found. and a freeze frame shows that the o2 sensors are getting worn out.

 

No, this sounds more like an engine issue unless you have slipping transmission which you would have mentioned by now if you did.

Speaking of engine problems, what sort of problems did your Blazer have that caused you to use octane booster? Did you have pinging and predetonation that you were trying to quiet down?

You mentioned on 11/26/08 you were going to take it to a second transmission shop and get a second opinion, what did they tell you?

 

Have you checked the back pressure yet? It could be the cat is getting plugged. On my blazer I had a similar issue, with mine though I played around with the MAF sensor because it was dirty, I noticed the hessitation with the MAF sensor connected. If I disconnected it it wouldn't hessitate but it would shift crappy. I thought it was the tranny too, but it seemed wierd that it would shift good with the sensor "on". I was running it with the sensor off for a while till one day it just flat out hessitated (Bogged/Jerked)even with the sensor off. In the endI took it to a shop after they tested the back pressure and it turned out to be a plugged cat. It is running stonger than ever now!!![sm=gears.gif]

 

the second trans shop wants to keep the truck over night since it seems to only do this "jerking" in the morning time. the octane booster was to get the most miles per gallon since at the time gas here was at $4.50 a gallon or so. i stopped using it cause now the gas is $1.49 per gallon, and $20 fills my truck up. as far as the pressure goes, the exuast seems to be coming out ok. when you first start the truck you can see the condensation and the more you press the pedal the more comes out,(obviously). i guess i could unplug the maf sensor and drive it and see what it does.(if that is what you mean) and this morning when i got in the truck after reseting the computer the previous night, the motor ran excellent, plenty of power like when i first got it. but it did jerk a total of about 3 or 4 times (lightly, but has been a hard one or a soft one at random). this afternoon when i got off work it jerked twice going into second gear and hasn't done it the rest of the day. i changed my sway bar bushings and end links and went for a test drive and it seemed to be a little sluggish.

 

Save yourself the $$$ and change the 4L60E torque converter lock-up solenoid... my 97 shifted violently and stalled .... i paid the dealer for the diagnostic and replaced it.. no problems ever since

 

transmission is perfectly fine. the engine is causeing the jerking. the truck has made it perfectly clear. it has now started doing it upon start up and idle and shakes randomly at a rev.no light still. took it to a shop and they put a small spy like camera into the upper plenum and i saw everything but he could not find the pressure regulator, i know why cause it ain't that big. he said it is either the press regulator or a hole in the injector tubes. that is causeing a negative reading from the o2 sensors. he said the truck is trying to compensate for the problem. time to get me a book.

 

haven't got time to re-read this whole post(gotta go to work) ever do cap and rotor-this is a second time saying that but.....had one like this once and.......Happy Holidays! Jerry

 

So you have verified that the fuel system bleeds off pressure after the pump has shut off? Did you run down through the DIY pressure testing article to pin point the failed component?

The FPR is located off of the back of the SCFI spider. It is very difficult to see from inside of the plenum.

A leaking injector tube is a possibility, but unlikely. The stock SCFI spider has electronic injectors in the main injector body with pressure actuated poppet nozzles at the other end of the tubes. If the tubes leak, it would only allow the fuel supplied into the tube by the electronic injectors to leak out, possibly not actuating the poppet nozzle. But again, this is quite unlikely.

 

It's already been said a time or twobutthe problem is the ignition switch in the column. You can keep dumping money in it and waisting your time but the ignition switch will fix your problem!!!!!! The lights don't have to flicker or anything lemme tell you what is gunna happen...You will be in your ride in good clothes stop at the store or gas staition for a min. You will come back to start your ride and it will not start. So you will call your buddy to come chain pull you home then you will reallize that the ignition switch went out and now you can't put the truck in neutral.Now your on your back (in good clothes) taking off the shift linkage to get the truck in neutral to get it pulled home. This has happened to me a few times with different 95-97 blazers and it always started with a mis at cruising speeds then went to a hard to start in the mornings and every once in a while die at a red light. Then there it is dead on the road waiting for a ride....CHANGE THE SWITCH MAN