Car Run and Revs Fine...BUT
 

Alright, car runs and revs fine but when it gets down to idle, it will idle fine...other times it will surge to about 2k twice, then die. It is not the engine stalling, appears to be an electronic problem. Battery was tested and it was fine, terminals were replaced and I am still having the issue. When it comes down to a stop after moving, it dies smoothly..to the point you couldn't even tell. Any thoughts..?

How many miles since the coils, plug wires, and plugs were replaced?

Have you cleaned the MAF?

6k miles since coils.
1k miles since plugs

assume plug wires were replaced with coils, but unsure.

could it possibly be an issue with any sensors? (eccentric shaft/crank angle sensor?)

Possible yes, but not the ECU side of that, as they were reset when you disconnected the battery (which I assumed happened when the terminals were replaced). If the e-shaft sensor is physically dirty, that could cause it, and is a simple check.


There are actually quite a few things that could be causing this, just the list is a bit alarming :) Gotta start eliminating individual reasons, and the ignition is a common culprit for idle issues.

- MAF sensor dirty/bad
- E-shaft sensor dirty/bad/out of profile
- Coils failed
- Ignition wire(s) loose
- Plug(s) fouled
- Primary fuel injector failure
- Compression loss
- Carbon caking
- Fuel pump failure
- Fuel Filter clogged/restricted
- Throttle body restricted/carboned/failing
- Intake valving restricted/carboned/failing
- Vacuum leak





I think that's everything that comes to mind that could potentially cause this.

Each item generally has other things that it affects though, so it's a diagnosis process to eliminate each.

Okay...I'm going to start with dirty sensors, coils, and wires. Before I got it running, 2 leading coils were not sparking..is this normal operation? if not, what is the #1 culprit? Any advice on order of checking these? Any tips are helpful

No, all coils should be operating cleanly without issue. They will start causing problems well before they actually fall below minimum approved spec. Typically the coils will last 30,000 or so, sometimes failing as early as 15,000, or lasting as long as 35-40,000. And when they start to fail, usually it is just 1 first, but the others start failing as well after that.

Which coil is the first to start failing (leading or trailing, even front vs rear) can easily change what symptoms you see.

So do you think the best bet would be to buy new coils?

Check the throttle body for carbon buildup if u see some clean it off with MAF cleaner