Plug change makes things worse on '97

S

Some Car Guy

Registered
I've been having a stumble or bucking in my new car that I just got. It has 74K miles on it. My old car had a similar problem that caused a check engine light. The new car does not have a check engine light on.

My last 97 had several things to be done so I let my mechanic change those plugs and boots. So I had no idea what to expect since I haven't done this job myself until today.

The change went relatively simple with no problems. However, only 2 boots were very snug and came off with a "pop". Those two were on two new looking coil packs. The rest were all what appeared to be the factory boots and coils. Those all came off without any apparent friction.

The boots all were soft and had no cracks.

I coated all the boots with dielectric grease before reinstalling. I'm getting ready to go out on the test drive but I'm wondering if eventually that grease will dissipate and I will again have the miss.

The plugs I removed were Bosch Platinum. I have seen on here that some people do not like those plugs. I wonder if that has caused my miss because the electrode looked nothing like anything I have ever seen in my 15 years of shade tree mechanic work.

I installed NGK TR55IX iridium plugs and coated all with anti seize.

One other thing I noted was that someone had installed a K&N air filter. I had to order a regular filter at the parts store. Possibly that let the MAF sensor get coated??? I didn't see anything that looked dirty in the MAF.



After a short drive things were all good. I figured that I had cured it. THe next time I drove the car has an awful miss and bucking to it. So I'm actually worse now than before the new plugs.

If anybody has any comments about any of these things I would greatly appreciate the help.
 
have it scanned even though you have no C.E light the car may have stored codes that need to be cleared or addressed.
 
It can still be a bad coil boot, and you can clen the mass air wires with CRC Mass Air Flow Sensor Cleaner. Also did you change your PCV ?
 
I'm loading ATap on theis computer now

I installed 6 new boots, I left the two newer ones in for now.

New paper filter is in as well.

I took the PCV out and shook it and it moved freely.
 
Well crap

this computer crashed a few months ago and I haven't used Atap until now. I recall I had to call and get the techs to tell me how to make it work. SOmething like a bridge connection wasn't enabled. Guess I have to wait.:mad:

Maybe I can find a Atap expert online and get it done today. I hate problems like this. I have time today to work on it and I hit a roadblock.
 
Sounds like a mis fire to me....

If the car idles good, but under load it bucks, most likely you have a bad boot. Take your car to AutoZone, have them scan it or buy the $149 scan tool and scan it yourself. The new scan tools are much easier than using a computer based tool.
 
I got the Auto Tap to work and it is much better than any scan tool

There were no codes but since ATap logs pretty much everything I found the cylinder that misses.

I now just need to know how the computer views the engine.

Is it 1,3,5,7 down the drivers side and 2.4.6.8 on the passenger?

Or ?

I can swap out the coils to confirm but knowing that now would save much time.
 
Here are the highlights of the results from the day -


1. Found steady misfire on drivers bank, moved around coils and then changed out the bad one.

2. Car still ran poorly. So I hooked the AutoTap back up and found a problem with misfires on the passenger bank at the # 1 cylinder.

3. Moved coils arouns on that side.

4. Still had misfires on the # 1

5. Checked connector and found it was snug.

6. Put some dielectric grease on connector and replugged into the coil.

7. Same results.


So I guess the next step is a new harness?:mad:

Comments please.
 
I was reading another post where the guy has a car with no codes.

He stated that the original owner had a K & N filter in the car. My did also until today.

Maybe the MAF needs cleaned enven though I see no crude on the little sensor wires. ???

Could that do some weird things in the computer due to a wrong reading from the MAF? Seems to be a reach but this is a hard to figure problem.
 
Pick up some aerosol electronics cleaner and spray the MAF sensor clean to eliminate the possibility of contamination.
 
A dirty MAF wouldn't cause a cyl #1 misfire. Swapped coils AND boots? Swap plugs and try that.....

Rule out one problem before going elsewhere.
 
UPDATE!!!!!!!!!!!

Finally got time to work on it today.

Changed the # 1 plug to the # 2 cylinder

Started car and CEL came on for first time.

Scanned and found # 2 cylinder misfire

Got new plug and cleared code.

Started, no light, didn't feel mis as before when no CEL condition but computer was showing misfires.

Went on test drive. Better but STILL HAS A MISS. STILL!

Hooked Atap back up and only thing I can see is the # 1 injector shows an "YES" under open/short table. It is the ONLY injector showing that.

So, not knowing a lot about that perticular table, is that telling me bad or at least dirty injector? Most of the tables has a description of what they are showing but that one doesn't. I would think that it being only one of the 8 to show that that there is a problem.
 
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