Hey guys and Gals i have a wonderful 99 Chevy blazer that ran like a champ when i bought her used from a bank. since then oh lets say almost year and half ago But recently she has become the biggest BIT*H on the face of the world.

So far i have Replaced the plugs (autolite Plats) wires (bosch) Cap & Rotor (Acdelco) Coil (Acdelco) New spider injector MFI conversion (Delphi) new Fuel pump (68PSI idle-78 WOT at intake shredder valve) (Delphi) New fuel filter (WIX)

I have already done alot of work on this blazer with no success i have checked and rechecked my work iv done to this blazer and every thing has checked out every time my blazer is Miss firing on the #2 Cylinders at all RPMS im currently running at 66 PSI Fuel pressre idle and allmost 78 at WOT so i know for a fact that im getting GREAT pressure at the TB for the injectors But when the engine is running #2 cylinder is DEAD untill it runs for ohhh 20 30 mins then it smooths and the injector starts firing/opening but under heavy LOAD it backfires up the intake like its out of time but its not.

If u let the engine run and listen to it u can hear one maybe two of the injectors TICK real loud u can hear it though the plenum (no its not a valve tick either it only does this when the miss fire happens) When the engine is cold #2 cylinder is dead entirely and the injector ticks very loudly the entire time until it reaches a temp of 160+ then will smooth out but still do it under WOT and back fire through the intake. i have done a Compression test on all six cylinders and each and every one of them had over 150 PSI i think the highest was 168 PSI cylinder #2.

I have not tested the CPS or the Coil pick up under the Dist. cap or the ICM.

Guys i need any info and help u can give me because my wallet is getting thin and i cant just keep replacing parts hoping that my shade tree experience is gonna shine iv replaced what i did because it was either bad or needed replaced due to ware

 

How many miles?

It may not be your valves at all but on the way one in our 1998 S10 it started missing after I got it up to about 3K RPM but the misfire would go away.

We pulled the old 524K mile engine yesterday and there was a lot of varnish like build up in all parts of the crankcase. I wish I had did the Sea Foam engine soak as per instructions on the can/their web site to help clean the valve stems.

From time to time #5 in our case would hit until it finally stuck a bit open. Not sure what your problem it but I expect it may not be fuel/spark related but an issue with the valves since it goes an comes.

There is a lot of info on sticking valves issues on the web I found.

Keep us posted.

 

I dont think it would be the valves this engine has im gonna round up here 230k miles on it and the bank that i bought it from said that the engine was rebuilt i mean for the miles she has on her not a valve rattle one iv never herd a blazer run so quite at idle.

I mean I cant honestly say that one or two of the valve aren't sticking but i have never been late on a oil change and i sea foam it every oil change i mean could it really be a stuck valve. Wouldnt u hear the rocker arm slaping the valve if it was sticking open slightly?

iv had some mechanics tell me that the the injectors aren't getting fired/opened and others tell me its cap and rotor when all that shiz is NEW i mean yes i know i could have gotten a DOA parts but its all ACdelco and Delphi.

Since today is my day off im gonna check the CPS and see if the connection is good and the pick up coil/interrupter on the dist. im sick of this come and go dead cylinder but it never entirely goes away 3k rpm and higher it's back firing out the intake.

 

Backfiring out the intake means that intake valve is open.

Why is the question?

Is the valve sticking open?

Is the distributor worn so bad it is letting it fire at the wrong time?

In the 524K mile engine we pulled yesterday it had a new distributor in it due to misfiring per the seller and we could tell the distributor was new and even the rotor and cap still looked new.

Twist on the distributor and wiggle it and see if you feel much movement.

$150 distributor would be a cheap quick fix.

I bet they rebuilt the engine and left in the old distributor.

 

Well i know the housing is the factory but the cap and rotor have been replaced And no the distributor does not move in the block.

I had called one of my old collage teachers where i took autotech couple years back and he's saying that the computer is faulty advancing the injector timing to much making it not run right i mean he also mentioned the CPS could be going out but he also commented that when they go they just quit and wont start.

Edit: the blazer will idle fine but when u first start it #2 cylinder will not fire for the first 10-15 mins then it will idle on all cylinders with a #2 missfire here and there u can all hear the injector on #2 tick when it miss fires u can also hear a tick in the stereo when its on in side the car when it miss fires like somthing is shorted out but i have checked all the injector wires there are no bad places in them, when u drive the blazer and go WOT that #2 cylinder dies and will not fire like its getting no fuel and the stereo will make that ticking noise violently through the speakers.

 

Put your old injection spider back in the car. One reported that fixed his miss. As any shop can tell you there are BAD new parts too.

Could it be the valve lifter you hear click instead the injector. Not sure I have ever heard any injector sound on the 1998 or 2002.

 

Nah its not a valve train tick i did want to ask what senser tells the comp to fire the injector/s the pick up coil under the dist.... or the CPS?