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Discussion Starter #1
Ok I have an odd problem I can't seem to figure out. I have a 94 S10 Blazer 4.3 TBI. When I'm driving, I will get this hesitation like it dies for a second and then it comes back. Almost sounds like a click or something in the engine area when it does it. It's real quick and only happens randomly. For a while it will run just fine, then the hesitation will come in for a bit, then it runs good again. I checked my distributor cap for any cracks of some sort. Wires, plugs, cap, and rotor are all new. Just the other day I decided to just push on all the plug wires and make sure they were tight when the truck was running. I went to make sure the end that goes to my coil was snug and got a little shock. Took a closer look and saw that it was arcing from the plug wire across to a red wire close by. Not sure what that controls but it appears to connect from the coil back to the distributor. I replaced the coil wire, the arcing is gone, but my hesitation problem still remains. Not sure what to do now. Any suggestions?

Josh
 

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i got a 95 4.3 tbi and mine does that too. i got all new plugs wires cap and rotor and its like a hiccup when it does it. it sounds like it cuts out for a split second then comes back and u can hear the rpms go a lil higher than what they were at. mostly does it when the motor is cold but it mite do it when its hot i just havent paid much attention cuz its not bad enuff to where it stalls the motor. i really have no clue what it is. i cleaned my throttle body out just for the hell of it and it didnt do nothin and i got new fuel filter so its getin plenty of fuel. hang in there man. this boggles my mind as well
 

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my 91 4.3 tbi was jacking up like that, but it was a mix of a bad water pump, and a problem with the diaphragm (gasket) under the throttle body
 

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mine will do that sometimes also. but its never all that bad and i really dont worry about it. i got a 94 4.3l CPI
 

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Discussion Starter #5
Well...

I wouldn't really worry about it if that was the case. But this is to the point where when it does hesitate stuff falls off my dash. I can definitely notice it.

Thanks,
Josh
 

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Still no progress....

Well I've checked things over and over again, still no progress. Not sure on how to test the TPS. The noise had started getting worse so it's been parked now. It almost sounds like a backfire, but it isn't coming from the exhaust. Is it possible for the injectors to give too much fuel? Not sure if this was normal, but I noticed on the top of the injector assembly there seems to be an excess amount of gas. When an ignition module fails does it quit running or would it still alow the truck to run? I replaced the coil, didn't really think that was the cause, but I wanted an MSD coil anyway.


Josh
 

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I have the same problem, almost sounds like a backfire, when you're driving comes from passenger side of engine seems like.. My camaro used to do that when my gas tank was empty just before it stalled..

It seems like it isn't getting gas, thought b/c my speed sensor wasn't hooked up that could be the problem.. If thats not it i'm thinking TPS i have no f***ing idea, it happens about every other day sometimes more and it's getting really annoying..
 

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my truck did that

my truck did that, after a while it started throwing a code, but i figured that since it was right after my hedder install it was just figuring stuff out, but now i know that is was the ignition control module hidden under the distributor cap... it's a $55 part from O'Reilly's tooke me maybe 20 min to replcae, but i dunno how hard it'd be with a CPI though i have TBI
 

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Would adding the MSD coil solve this then?
 

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I think around the 94 or 95 model year was when a lot of car makers were changing from OBD I to OBD II. I know around that time dealers seemed to be getting 94s and especially the 95s in for all kinds of problem related to OBD II. This is a longshot, so I wouledn't think that could be the main culprit.

I have a '92 Blazer 4.3 (doesn't have that problem) but with the CPI setup. Throttle body injection is not the greatest setup because it doesn't have very even fuel distribution and doesn't mix very good with the incoming air. Some cylinders might be getting more fuel than others.

The only other thing I could think of is is the EGR or PCV valve or the Idle Air Control Motor.

That's my two cents on the whole problem.
 

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Discussion Starter #13
Still lost...

Well I've looked over just about everything you guys have given me. Only thing I haven't checked into yet is the PCV valve and Idle Air Control. I went to the junkyard and got a TPS only to find that though it looks the same between TBI and CPI, they aren't. They turn opposite ways. So I guess it could possibly be the TPS still. It is definitely a backfire coming from the throttle body. When I rev the engine from under the hood I can hear the noise coming from there. Well I'm off to check the IAC and PCV valve..see what happens.

Josh
 

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Discussion Starter #14
It's fixed!!

I decided to look into that excess fuel I had seen on top of the throttle body. I bought a TBI rebuild kit for $40 or so and put that in. Runs perfect now. I'm thinking it was the fuel regulator diaphragm which came with the kit. I spent almost $200 in various parts to find out all I needed was a $40 rebuild kit. Guess that's the way it goes.

Josh
 

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Discussion Starter #15
Bad news....

Well it's back to the hesitation crap again. Any reason why the fuel regulator would fail so quick? I took it out and there was a tear in the new regulator I had just put in a couple months ago.

Josh
 

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nm

Check whatever the red wire went ot. It probably wasn't something that could withstand 40,000 volts of power, even intermittently. If it went to the ECU maybe the ECU is bad now, or at least the portion that controls whatever the red wire went to.
 

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I had a similar problem a while back. It ran real crappy and jerked the crap out of me on acceleration. I replaced my plugs, wires, cap & rotor and didnt do anything. So then I said what the hell and replaced my coil and it hasnt acted up since. But if you said you already had it fixed, then I dont know if this could be it
 
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