1998 Blazer P0302 / #2 Cyl Misfire Detected

My 1998 (130000 miles) 6cyl, 4.3 (EDI with CSEFI) has been sitting in my garage for 3 months and I cannot find the problem with this P0302 error. Something IS misfiring (probably not phrased right) and it's drivable but I do not drive it. I've looked on the darkest of nights for an arc but see none. I do however seem to hear and arcing sound but my hearing is not what it used to be I'm afraid.

The error suggestes a number 2 cylinder misfire and below is a list of what I have done so far:

1.) Tested spark from coil...OK.

2.) Replaced 6 spark plugs with AC Platinums.

3.) Replaced 6 Plug Wires and coil wire with Top End Wires.

4.) Replaced Distributor Cap and Rotor (twice). It now has a Borg Warner Cap and Rotor.

5.) A month or so before the P0302 error the Fuel Pump was replaced. That is about the third one I've gone through.


Question::: My code reader is a little cheapie I purchased for about $80. Could the reader just be showing me a "default" error in the P0302 on not other errors that are causing the P0302?? In other words, displaying the symptom and not the fault?


I have read on this forum and through my trusted Chilton/Haynes repair manuals and they suggest that it could be just about anything from a throttle position sensor (TPS), to a distributor problem that the Camshaft sensor is bad. EGR valve malfunctions have also been cited as a possibility.


Naturally I hate chasing my tail and throwing money at it and guessing. I have ran Seafoam twice.

I would take apart the fuel injection system and try to clean it up but have never been down that road before. I'm a fair mechanic but a bit short of funds working in a freezing cold garage. I don't want to create more of a problem than I already have. But I HAVE to do something here.

I read on this forum where a guy with the same code finally brought it in and it turned out to be a bad injector. I just read yesterday where another guy went to a salvage yard, bought the distributor with the camshaft sensor, installed it and THAT took care of the problem.

So again, back to my question on my code reader. Could it have another codeable problem and the reader simply displays the symptom code?

Does anyone have any experience as to what might be a COMMON problem or a fix that is more likely to solve this than another.


This guy sure would appreciate some help.

Thanks-in-advance,

Paul

Does the engine have a dead miss on no 2 cylinder?
Does the check engine light blink on the road?
Have you cleared codes and rechecked for codes?

Does the spark plug on no 2 cylinder look wet when you pull it out?
Has that cylinder got good compression?
Have you tryed switching plugs plugs and plug wire for that cylinder?
Is no 2 cylinder getting good hot blue spark to no 2 plug?
MT

You mentioned "Top End Wires", some manufacturers "Top End Wires" are sub-standard, what brand did you purchase? Did you apply silicone dielectric grease on both ends of the plug wires and to each terminal inside the cap?

You also mentioned that you hear "arcing"; while the engine is idling, try directing a mist of water over the ignition coil and plug wires, it may help you locate the arcing.

Well, I'm not quite sure what a "Dead Miss" is. I would imagine that it possibly describes a complete absence of spark and I do not know that is the case. I would guess that it does have spark but I will check it.

No, I did not apply electrolytic grease as was suggested. You also mentioned applying this grease under the cap and between the electrodes?

What happens with the light is this....I clear the codes, start the vehicle and after running for about a minute the light comes on steady and the code reads, "P0302." No other codes. No blinking light.

The # 2 plug did not strike me as being wet although all plugs were in rough shape and sorely needed replacement which I did.

I cannot remember the OEM of the plug wires but I know they cost me around $70 and were the best I could buy for the motor.

Double post
Sorry about that.

A dead miss is a cylinder that is missing all of the time and has no affect on rpm with the plug wire on or off.

If light comes back on that soon after code clear.
You have a bad miss on no 2 cylinder.

Check for good hot blue spark to no 2 spark plug.
If good hot blue spark pull spark plug and see if it is wet or has gas on the end of it.

If wet on the end recheck for good hot blue spark and switch or check spark plug.
Recheck plug gap and look for cracked porcelain.
Also if you have a compression gauge check compression on that cylinder and several others.
If over 12-20 lbs difference post back compression readings.

If spark plug is staying dry on the end look at and check injector and injector pulse and check for vacuum leaks.
MT

First off, please forgive not posting but I was otherwise occupied. Now that the weekend is here I have some things to report on this issue.

I just came inside from pulling the # 2 plug wire from the plug and connected a spark gap checker to the wire and started the motor. The gap on the checker was adjusted to approx. 3/4" and with the engine running I noted what appeared tobe NORMAL SPARK jumping the electrodes on the checker. There was no sag and it appeared healthy. There did not appear to be any intermittant. Just a regular duty cycle as I would expect. The color does not appear to be true blue but a very light blue.

So the code reader I own is giving me a P0302 error (#2 cylinder misfire detected) but there does not seem to be an issue with spark. I do not own a compression guage.

I guess that at this point I would have to ask how to check for "Vaccum Leakd" as MT-2500 suggested.

A bad spark plug or vacuum leak or injector/injector pulse or low or no compression can cause it to miss.
Is the spark plug wet on the end with gas?
Start with switching spark plugs and or wires with another cylinder and see if miss moves to another cylinder.

I've been having the same problem. Replaced plugs, wire, cap, ignition rotor. Low compression on cylinder 3. psi=80. Any idea what causes this, and what it takes to remedy the problem?

Thanks for your help. This forum is really good.


--Ryan

I've been having the same problem. Replaced plugs, wire, cap, ignition rotor. Low compression on cylinder 3. psi=80. Any idea what causes this, and what it takes to remedy the problem?

Thanks for your help. This forum is really good.


--Ryan

If one cylinder is Low on compression is is pull the cylinder head and repair.
Run a wet compression check to see if it is a bad valve or piston rings.

For help on it it would be best to start your own post/New thread and someone will help.

MT