Rough idle in drive, bogging at lower speeds

When it rains, it pours for me. After the fuel pump fiasco, I got a whole 2 days of trouble free motoring before everything went to hell again. It's been raining a lot this week and on my way home yesterday I noticed I had really bad idle issues when I was at stoplights. It was to the point my car had issues going again. But once at speed, things seemed to improve. My dad told me to look at my coils and see how the grease had held up. I asked him back what grease? His diagnosis was a coil pack shorting out in the rain. I tried to tell him it sounds like fuel delivery but 60$ later with 3 brand new coils I still have the idle of a model T

Here's the list of recent work
-New MAF sensor ~3 months ago
-New CORRECT fuel pump a few days ago, has worked fine
-New coils w/ dielectric grease on the seals to keep out the rain
-New plugs/wires 4 months ago or so

Here are the symptoms
-Rough idle when in drive (~700 rpm)
-Bogging heavily off the line
-Steady cruising, no issues
-Gets worse as the car heats up
-Semi-rough shifting from 1-2
-Electrics flicker when the bogging happens. Nothing dies but my lights seem to flicker a little bit to where its noticeable. However, the battery and accessory wiring seem fine when the engine is off so I'm pretty sure it's not that.

I'm unsure if the shifting is related as it's pretty random on my car and only happens if I go slow. Holding a speed the car will do all shits just fine.

So what's next for me to try?

Not sure yet what you're problem is, but keep a hold of the OEM coils you replaced. Three new ones for $60 is a great deal if you found OEMs, but in case you bought an off brand, I imagine your originals are more reliable.

They were NAPA's off brand but in all regards they look and feel identical to GM's OEM stuff. In fact I think their electrical connector has a bit of a better design, much tighter fitting to help keep out water. Or mine were that worn. Either way, one of the coils had a corroded connector to the ICM and was giving me a really weird spark when I checked it but it was not "dead" just "dying". All the salty michigan slush in the winter probably would've killed it soon anyways.

themanwithsauce wrote:

When it rains, it pours for me. After the fuel pump fiasco, I got a whole 2 days of trouble free motoring before everything went to hell again. It's been raining a lot this week and on my way home yesterday I noticed I had really bad idle issues when I was at stoplights. It was to the point my car had issues going again. But once at speed, things seemed to improve. My dad told me to look at my coils and see how the grease had held up. I asked him back what grease? His diagnosis was a coil pack shorting out in the rain. I tried to tell him it sounds like fuel delivery but 60$ later with 3 brand new coils I still have the idle of a model T

Here's the list of recent work
-New MAF sensor ~3 months ago
-New CORRECT fuel pump a few days ago, has worked fine
-New coils w/ dielectric grease on the seals to keep out the rain
-New plugs/wires 4 months ago or so

Here are the symptoms
-Rough idle when in drive (~700 rpm)
-Bogging heavily off the line
-Steady cruising, no issues
-Gets worse as the car heats up
-Semi-rough shifting from 1-2
-Electrics flicker when the bogging happens. Nothing dies but my lights seem to flicker a little bit to where its noticeable. However, the battery and accessory wiring seem fine when the engine is off so I'm pretty sure it's not that.

I'm unsure if the shifting is related as it's pretty random on my car and only happens if I go slow. Holding a speed the car will do all shits just fine.

So what's next for me to try?

When was the last time you removed the throttle body and cleaned the IAC and EGR air passages? As well as the backside of the TB?

FOund the culprit, my battery terminals had corroded because water seeped in through a hole in my fender well. Cleaned the terminals and the car is back to the way it was. Still needs work but now it's back on track. Although the coil terminals were also quite corroded so in a way I'm glad I had that area cleaned up. I'm still amazed that it never threw a code. Jessica is an absolute tank. Refuses to admit that anything is wrong.....or maybe that just means she's a woman

Which makes me think of my issue I posted earlier. Any chance your filler neck has a rust hole you are unaware of? Lose any fuel when you really fill it up? Never mind, you found the issue as I was posting. Carry on.

themanwithsauce wrote:

FOund the culprit, my battery terminals had corroded because water seeped in through a hole in my fender well. Cleaned the terminals and the car is back to the way it was. Still needs work but now it's back on track. Although the coil terminals were also quite corroded so in a way I'm glad I had that area cleaned up. I'm still amazed that it never threw a code. Jessica is an absolute tank. Refuses to admit that anything is wrong.....or maybe that just means she's a woman

That's a new one on me.

Might want to check the subframe and its mounts, and the rear suspension links.

Albertj

The problem area lies in the rear fender wells. The metal has started rusting away and has allowed water to seep into certain cracks and ridges in the frame and body work. Aside from replacing the fenderwell liner, I also have to get the fiberglass sealant out and patch/repair it from the trunk.

themanwithsauce i have a very similar problem. my car sounds and feels like its missing, bad. the lights have a slight flicker when it idles and when i accelerate to lets say over 35 its starts bogging and almost sputtering. it cuts acceleration drastically. i have changed the coil pack, messed with the plug wires but none of that seems to calm the roughness of the engine. is it maybe a fuel pump problem??

adri wrote:

themanwithsauce i have a very similar problem. my car sounds and feels like its missing, bad. the lights have a slight flicker when it idles and when i accelerate to lets say over 35 its starts bogging and almost sputtering. it cuts acceleration drastically. i have changed the coil pack, messed with the plug wires but none of that seems to calm the roughness of the engine. is it maybe a fuel pump problem??

1st instinct says this sounds like bad plug wires or plugs. Possible a nearly clogged fuel filter. What does "messed with the plug wires" mean?

well, one of the plug wires is damaged but we did some temporary repairs to it in order to save some money. it may sound like that may be the problem however after driving the car after we did that it didnt miss at all, but after a while it began to miss again terribly. so now we are thinking that it is a bad fuel injector. but idk

adri, you need to change all the plug wires before you do anything else.

ok, ill do that, cause after all it really could be the plug wires. Thanks!