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06 black awd tbss
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Discussion Starter #1
Guy's, I've been having problem's with my 94 4.3 s10 blazer. Now, she has well over 200k on the motor. It's the CPI engine, not the TBI. It looses a little antifreeze but nothing major. She's a tank and has been nothing but good to me over the year's. But as of late, every morning, she just doesn't wanna start. The motor will crank and crank, but its almost like theres no fuel or spark to start the engine. After trying for about 3-5 minutes, she finally turn over, but its almost like the engine backfires from the header's, or somewhere from the motor, not the rear of the car, like it would be from the exhaust, when it finally does decide to turn over. But it only ever does this in the morning. Once it's been driven for the day, or just around the block, it'll start like a champ the rest of the day.

The plugs have been replaced with in the last 10,000 miles, as well as I have Taylor 8MM wires on it (though they've been on it for a few years). I replaced the infamous "spider" injector within the last 5-10,000 miles as well. And when the engine run's, it runs fine... Other than the part I'm about to explain next...

While driving down the road, i could have the throttle at a steady spot (not giving it gas, or letting off) and the car just looses power... It doesn't loose power like its trying to stall out or anything (then again maybe it does), it just want's to fall on her face, and in turn, slow's down. So I put the pedal down and down, til it'll finally down shift and act like I mashed the gas to take off or something and then we'll be fine, but it'll come right back again. And it also does the same "backfire" noise as when it won't start in the morning. It comes from under the floor boards right at my feet. As if the car, again, is loosing spark, or fuel, or something along those lines. And when it does start acting like this, it act's as if its going to stall out at idle, so i tend to "double foot" it just in case.


I'm thinking it has something to do with a spark issue, or fuel issue (unless that sound's completely out of the question). Any idea's or tip's on where to start. I really don't wanna drop it off at my local shop, just to have them tell me they can't find anything wrong with it. Or tell me its something internal. Because that's how my luck goes. It tend's to not wanna start when its colder out, and same goes for the other problem, when it's snowy/cold out.

I'll have my camera with me, just in case it start's to act up, ill take a video of it.
 

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Trailblazer SS
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injectors? or fuel pressure?
 

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TrailBlazer SS AWD
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I Just Dealt With This On My 1992 S10 As Well As My Couzins 1996 S10. It Was A Fuel Issue On Both Truck, The Problem, The Fuel Filter. The Filter Is Located On The Drivers Side Along the Inner Frame Rail Behind The Front Door And Before The Rear Wheel. Make Sure You Spray The Crap Out Of It With A Penetrant Spary. Mine Came Out With No Issues But On My Couzins I Had to Cut The Steel Line To Get The Old One Out And Reinstalled It With A Piece Of Fuel Line And Some Clamps. It Will Be The Cheapest Thing You Can Do. I Did It Laying On The Ground And Almost Got A Face Full Of Gas, So If You Know Someone With A Lift And Even Better A Set Of Flare Wrenches, Go To Them. Also Clean Your Throttle Body And Replace The PCV. Good Luck.
 

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07 TrailblazerSS Imp
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9,386 Posts
OR it might be the fuel injection "spider" inside the intake. On my 93 Jimmy I had a problem with the fuel leaking inside and causing hard starts. I ended up replacing it for about $300, but tht was years ago. The CPI intake on that comes off really easy. Might take ya 15 minutes. If fuel filter hasn't been changed, I would check that too as was mentioned before.
 

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Premium Member
06 black awd tbss
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Discussion Starter #6 (Edited)
OR it might be the fuel injection "spider" inside the intake. On my 93 Jimmy I had a problem with the fuel leaking inside and causing hard starts. I ended up replacing it for about $300, but tht was years ago. The CPI intake on that comes off really easy. Might take ya 15 minutes. If fuel filter hasn't been changed, I would check that too as was mentioned before.


The plugs have been replaced with in the last 10,000 miles, as well as I have Taylor 8MM wires on it (though they've been on it for a few years). I replaced the infamous "spider" injector within the last 5-10,000 miles as well. And when the engine run's, it runs fine... Other than the part I'm about to explain next...

I'll try the filter, I know it was replaced with in the last few years. In fact, the shop wrote the date on the out side of it. so it shouldn't be to hard to remove. The blazer was my show blazer til i swapped the bodies. So the under side is pretty clean.

But would that make it "backfire" or what ever it's doing? I'm sure that's not what its actually doing, but that's the only thing i can say it sound's like to describe it to you guy's online.


One other thing i didn't change when i did change the spider injector was the fuel lines into the back of the intake. But when i checked them while i was replacing the injector, it wasn't leaking. And i replaced both injector and those inlet lines once already, a few year's ago.


The only thing that makes me wanna think that it isn't fuel related is it would act up all the time IMO. I've had the injector problem's and all that before, I've been down that road. And once it start's leaking, it act's up all the time, and doesn't idle for crap. But other than the hard start's in the morning, and it throwing this tantrum she's fine.
 

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AKA Sonny
TrailblazerSS
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I'll try the filter, I know it was replaced with in the last few years. In fact, the shop wrote the date on the out side of it. so it shouldn't be to hard to remove. The blazer was my show blazer til i swapped the bodies. So the under side is pretty clean.

But would that make it "backfire" or what ever it's doing? I'm sure that's not what its actually doing, but that's the only thing i can say it sound's like to describe it to you guy's online.


One other thing i didn't change when i did change the spider injector was the fuel lines into the back of the intake. But when i checked them while i was replacing the injector, it wasn't leaking. And i replaced both injector and those inlet lines once already, a few year's ago.


The only thing that makes me wanna think that it isn't fuel related is it would act up all the time IMO. I've had the injector problem's and all that before, I've been down that road. And once it start's leaking, it act's up all the time, and doesn't idle for crap. But other than the hard start's in the morning, and it throwing this tantrum she's fine.
dude you might wanna look into that cap and rotor on that engine since you already replaced the cpi and it runs ok when warm sounds like a spark issue here. I have pretty much the same engine on my vortec v8 i replaced the cpi when i bought it (the guy had no idea what made it run like shit so i got it for super cheap) it started to missfire here and there and one day it didnt start at all and would start hard on the starter i almost thought the motor was done seemed like it skipped a tooth on the chain. turns out i went into the cap and found some corrosion not alot but i guess enough for it not to start so i bought a cap / rotor and it fired right up just that little bit of corrosion made that thing run shitty all is good now just a thought if you havent done your cap and rotor.
 

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06 black awd tbss
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Discussion Starter #8
dude you might wanna look into that cap and rotor on that engine since you already replaced the cpi and it runs ok when warm sounds like a spark issue here. I have pretty much the same engine on my vortec v8 i replaced the cpi when i bought it (the guy had no idea what made it run like shit so i got it for super cheap) it started to missfire here and there and one day it didnt start at all and would start hard on the starter i almost thought the motor was done seemed like it skipped a tooth on the chain. turns out i went into the cap and found some corrosion not alot but i guess enough for it not to start so i bought a cap / rotor and it fired right up just that little bit of corrosion made that thing run shitty all is good now just a thought if you havent done your cap and rotor.

For some weird reason I believe it to be spark related as well. And i replaced something under the cap a few month's back, that some of the guy's over on my blazinlow forum told me to try. It was cheap, but it didn't do anything.

HA, I knew it was good that i alway's took picture's of everything i do. This is the part they told me to replace, which I did, and like i said, it didn't do anything. But from these picture's, can you notice anything that look's bad? Everything looked good under the cap to me, maybe the rotor need's replaced? I'm not to familiar with that type of stuff.







 

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07 TrailblazerSS Imp
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I always used the Accel cap and rotor which had brass terminals. What is all of the white corrosion looking stuff on top of the ign module?
 

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wow, something got all those pieces wet and they looked like they were wet for a while...you seemed to find the fix^69
 

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06 black awd tbss
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Discussion Starter #11
I always used the Accel cap and rotor which had brass terminals. What is all of the white corrosion looking stuff on top of the ign module?

I couldn't tell ya man. i had the cap and rotor done as well, a few year's back, after i first bought the blazer. but other than swapping out the plug's and stock wire's, i haven't done anything else with it. Other than adding an MSD Blaster coil. But as far as the cap/rotor, i haven't a clue.
 

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trailer park living.
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I'm not saying this will solve your problem, but i would check your timing. With 200k I'm sure your timing chain has stretched a little. If i remember right you have to undo the brown wire next to the computer.
 

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06 black awd tbss
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Discussion Starter #13
I'm not saying this will solve your problem, but i would check your timing. With 200k I'm sure your timing chain has stretched a little. If i remember right you have to undo the brown wire next to the computer.

i havent a clue as to what your talking about. my computer is up under my dash. so i don't know what brown wire there would be.


anywho... a little update. today i decided to take up the upper intake plenum just to see if the "nut kit" was leaking, or the spider injector, everything looked good from that aspect. but i did notice the gasket was wet with gas on top, and the back cylinder hole was wet. i never replaced the gasket the last time i had it all apart because it still looked brand new, but had bought one just in case. well i decided to put the new one on to see if that would do anything. as well as (dont know if i mentioned this the first time around) i changed the MSD Blaster coil i had on it back to the stock one. just to see if maybe the coil pack was going back.

i took it for a test drive. it seemed to idle a little smoother, and ran a little better. but it felt like it still wanted to loose power at a constant cruising speed.

so well see what happens over the next few days, or when i try and start it in the morning.


any other information that i could try to check out? maybe more so with the cap/rotor?
 

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trailer park living.
TrailblazerSS
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I know you computer is under your dash,I had a 2dr 94 s10 blazer with a 350tbi and a 6spd. There is a wire next to you computer that sticks out of the harness with a connector on it. you have to disconnect it to set the timing. Just a thought, don't know if it will make you problem go away.
 

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06 black awd tbss
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Discussion Starter #15
I know you computer is under your dash,I had a 2dr
94 s10 blazer with a 350tbi and a 6spd. There is a wire next to you computer that sticks out of the harness with a connector on it. you have to disconnect it to set the timing. Just a thought, don't know if it will make you problem go away.


ahh ok. i got ya now. and i actually think i know what your talking about. maybe ill give my buddy a call and well do that sometime next week.

im still led to think its fuel/spark related. then again i dont know how it would act with the timing off.
 

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2006
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From my experience with my blazer...

Spider injector
Cap/rotor/ignition module

spark plug wires, spark plugs.

If you replaced the ignition module and it looked like that....you should replace the cap and rotor as well and just give her a good tune up anyways. I always used ACdelco or Accel stuff with the good terminals (AC delco upgraded from original to the new stuff they sell over the counter) but that spider injector is notorious. GM's upgrade actually has six injectors rather then the poppet valves the old style used to have so it might be worth checking out again, I know you said you'd replaced it recently...but those things suck.

After all the simple stuff is looked at/taken care of....time to move on to the timing chain and other things that would effect your valvetrain events.
 

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06 black awd tbss
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5,953 Posts
Discussion Starter #18
From my experience with my blazer...

Spider injector
Cap/rotor/ignition module

spark plug wires, spark plugs.

If you replaced the ignition module and it looked like that....you should replace the cap and rotor as well and just give her a good tune up anyways. I always used ACdelco or Accel stuff with the good terminals (AC delco upgraded from original to the new stuff they sell over the counter) but that spider injector is notorious. GM's upgrade actually has six injectors rather then the poppet valves the old style used to have so it might be worth checking out again, I know you said you'd replaced it recently...but those things suck.

After all the simple stuff is looked at/taken care of....time to move on to the timing chain and other things that would effect your valvetrain events.


I've never dealt with changing a cap/rotor, are they hard to replace? i had the shop do that for me years ago. The plugs/wires are good. As well as like i stated above, i took the upper intake off last night, and turned the key on so the fuel pump would kick on. Saw no fuel leaking anywhere so that's good as well. Another thing these vortecs are known for is the EGR valve gumming up with carbon. But I also check that last night, which was clean as could be, as well as I already swapped out the gasket for the newer style with the screen in it.

I believe i will look into the cap/rotor next like you said.
 

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06 AWD TrailblazerSS
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200k on it, did you give it a compression test the cylinders? Loose of compression would defintitly make for cold hard starts and that lose of power feel.
 

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07,09 -3SS- Blk,Slv
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I've never dealt with changing a cap/rotor, are they hard to replace? i had the shop do that for me years ago. The plugs/wires are good. As well as like i stated above, i took the upper intake off last night, and turned the key on so the fuel pump would kick on. Saw no fuel leaking anywhere so that's good as well. Another thing these vortecs are known for is the EGR valve gumming up with carbon. But I also check that last night, which was clean as could be, as well as I already swapped out the gasket for the newer style with the screen in it.

I believe i will look into the cap/rotor next like you said.
It will take you longer to disconnect the plug wires from the cap than it will to change out the cap and rotor. Extremely easy and inexpensive to do.
 
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