Pesky miss... then takes off

[My_Silver_SHO]

I replaced the plugs, coil packs, O2 sensors, cleaned intake, MAF, throttle body, intake, and I still have low rpm miss. There are no codes.

Idle seems low and slightly rough. Car drives ok... but stumbles a bit then takes off.

Any ideas?

 

[My_Silver_SHO]

Could it be the Bosch 4 plugs?

 

[stephen newberg]

Yes, at this point it is starting to sound like plugs. I was planning on giving mine a new set for her 200k birthday, no longer very far away. Every now and then I also have a very light miss at low RPM or if letting the car bog down. I suspect it is one or two of the plugs, now approaching 100k old.

pax, smn

 

[My_Silver_SHO]

It was the DPFE... runs great now!!!

 

[stephen newberg]

It was the DPFE... runs great now!!!

You know, I cannot even remember what that stands for. Too many acronyms. Remind me, please?

pax, smn

 

[kevinspann]

Could it be the Bosch 4 plugs?

I'd certainly take them out.

 

[Fahrzeug]

You know, I cannot even remember what that stands for. Too many acronyms. Remind me, please?

pax, smn

It stands for Differential Pressure Feedback EGR. I've been meaning to look it up myself and you reminded me. :laugh_ti:

 

[98SF19]

In my quest to find the source of poor fuel economy, I disconnected my MAF to see if the car would run differently (previously cleaned MAF but with no change in mpg). Believe it or not, my fuel economy is slightly better with the maf disconnected, but I've also been getting very low rpm when starting the vehicle, almost to the point of stall. Then after about 10-15 seconds, it surges slightly, then settles around 900. I also get the stumble when moving from a stop, and it happens a bit more severely when the car has warmed up (I actually chirped the tires yesterday and they're less than a year old!). I have yet to clean out the EGR or even do a manual vacuum test on it, or clean the IAC. I hadn't thought to consider the DPFE though. If I still have the stumble after cleaning EGR and IAC and reconnecting MAF, I'll pony up for the DPFE.

 

[BamSHO]

Have a spare set of plugs standing by. Had Bosch+4 is the silver car didnt get 5,000 out of them. Couple plugs actually the 2 of the 4 outer electrodes bent in and grounded the plugs out. Went to Finewires and havent had any issues.


Brian Michael
98 silver Gen3