Help 4.3 all messed up

[wolftammer]

Well this is what ive done. Plugs not bosch, wires, rotor, rotor cap, throttle position sensor, Pcv valve, CPI unit (the passenger side was golden and clean, replaced the oil it was almost like i was drainin gas it was nasty), fuel filter... What else do i need to do to make this thing run better.
It runs with codes reading random multiple misfire, feels it too. what should i do??? HELP PLEASE.

[Blazing Rice]

Oxygen sensor...
Give that a try.

[Mikado14]

What year?

Are the misfires at idle only or during driving?

Did you do a Throttle Body service?

Did you try cleaning your IAC?

[BlazerLT]

Originally Posted by wolftammer

Well this is what ive done. Plugs not bosch, wires, rotor, rotor cap, throttle position sensor, Pcv valve, CPI unit (the passenger side was golden and clean, replaced the oil it was almost like i was drainin gas it was nasty), fuel filter... What else do i need to do to make this thing run better.
It runs with codes reading random multiple misfire, feels it too. what should i do??? HELP PLEASE.

Hello! What year do you have?

1.) Have you removed your EGR Valve and checked for chunks of carbon keeping the pintle open? <----Important

2.) Does the exhaust smell like rotton eggs?

We need to know the year before I can continue, I need to know that to see if your vehicle is computer timed or not.

Post back soon and remember next time to post ALL information.

[wolftammer]

Ok here it is its a 1995 4x4 LT 4 door vin (w) sorry bout not having all the info on my first post. The EGR valve was recently replaced and i took it off yesterday afternoon. not so sure but the other day it smelled like candels burning but that smell is gone so thats bout it. thanks

[wolftammer]

it missfires at all times like it has something to do with the way it is gettin its info from the computer not so sure though

[wolftammer]

hey one more thing how important is the idle air control valve???

[wolftammer]

any have any pics of where the knock sensors are i cant seem to find them

[BlazerLT]

Hold on their, please learn to edit your posts instead of adding a new post for one statement. Makes things confusing.

Please remove and check your EGR valve again and MAKE SURE that there is no carbon chunks sticking the pintle open.

Do not just ASSUME that it is fine because the valve was replaced. New carbon can be dislodged and this could happen several times.

Check it out and get back to us.

[Mikado14]

Just a thought, did the misfires occur after you changed the wires? Do you think that you might have two of them reversed or something?

The IAC or Idle Air Control is important! If it is not operating properly your engine would not hold a constant idle or perhaps not even idle or the idle could be too high. I have never seen a bad idle air create codes indicating a misfire, perhaps it could.

Again, did this misfire condition occur after you changed the CPI? Did you clean the hole of carbon prior to installing the individual injectors? Are you sure you seated them properly?

My '93 4.3 can be a bugger at times to get the cap seated, are you sure it is not cocked? Been stupid myself and did that once and it was misfiring.

Your second post you stated that you removed the EGR, you did make sure there was no carbon I hope.

I wouldn't jump the gun on the knock sensor.

Let's see, ummmm, your third post says it is misfiring at all times, I will assume you mean no matter what the RPM's are. So, I would forget the IAC for now and recheck your wires, cap, rotor and pulg gaping.

Good Luck! and get back

[wolftammer]

sorry bout the posts. OK i had the egr off yesterday and there was nothing blocking the pintel open. So what do you think i should do next. Thanks

[BlazerLT]

Reset the computer by pulling the negative terminal for 10 minutes and try.

Who did this work on your truck?

[wolftammer]

Well ive done all the work on my blazer i have never taken my vehicle to a mechanic? actually none of my vehicles go to the mechanic. Also i am on a military base where we have an auto hobby shop that has four certified mechanics.

I guess that i could try to reset my computer tomorow after work. What will that do?

The next thing is... I had the problem before i changed my CPI I had it after also but it wasnt as bad like is was something else. Yeah no carbon build up or anything.

so now im gonna check my wires and rotor and rotor cap its the flat one with the posts coming out the side of it. Does anyone have the firing order for it maybe i got bad info from mitchell on demand who knows.

Ok thanks for all the help ill get back with all of you. If you all think of anything else you know what to do thanks.

[Mikado14]

Here's something, check the coil. Wait until it gets dark and look to see if it is arcing to the metal holder. Also, look to see if it has evidence of arcing. You may have to remove it but you certainly can look at it when it's dark.

I have seen this in the shop and it can be tough to diagnose.

[wolftammer]

Thanks for the info ill check that one out in the mornin before i go to work. If it is goin bad wouldnt something like that totally mess up everything. Well i guess that is what it is doin well thanks ill get back with you on the flip side.