Jerking and weird idle on s14 ka

[WesleySnipez]

A couple days ago, I started my 96 KA s14, and let it warm up like normal. But when I went to move, the car jerked a lot between 2-3k rpm and would bog down to like 700 rpm. When it is on neutral and I'm just coasting, it doesn't do it, and after I drive about a mile it goes away and won't do it till I cold start it. I'm thinking it could be the fuel pump or MAF? Any suggestions?

[PapaSmurf2k3]

I'd check your engine grounds and connectors (MAF, coolant temp sensor) for corrosion. Also look for any split vacuum lines and such.

Have you tried pulling any codes from the ECU?

[WesleySnipez]

I have not pulled any edu codes yet! Ill check the vacuum lines. My egr isn't connected and it just closed the pipe that connects to the header with a bolt. So those vacuum lines might be it. But i will check for corrosion

[WesleySnipez]

Anyone else have any insight? I'm not too tech savvy so I don't know every thing that could be wrong. Thanks!

[PapaSmurf2k3]

What were the results of the checks you did before?
How do the engine grounds and sensor connectors look? Are there any codes in the ECU?

[WesleySnipez]

I didn't see any corrosion at all, and the MAF looked fine. I cleaned the throttle body out so I'll see how that works. I noticed that after I let the car warm up and then turn it off and unplugged the wires and plugged them in it worked fine. Ill see if the throttle body clean will help and let you know.

[WesleySnipez]

Cleaning the throttle body didnt help

[PapaSmurf2k3]

Have you tried pulling any codes from the ECU?

Are there any codes in the ECU?

[WesleySnipez]

Yeah I tried that too. But there was no led light on my ecu... I looked in the hole and couldn't see anything either.. Idk how that happens..

[PapaSmurf2k3]

You should be able to use your CEL on the dash as the LED light. It blinks the codes just like the light does on the ECU.

[WesleySnipez]

Ok I will try that when I get home tonight

[WesleySnipez]

So I pulled the codes and got 33 and 82 which are a o2 sensor and crankshaft position sensor and 93 which wasn't listed but I read someone else had the code and it had something to do with the evap sensor or something?

[WesleySnipez]

Still haven't figured out whats wrong. Im going to try to replace the maf and see what that does

[PapaSmurf2k3]

Did you first try the crankshaft position and O2 sensors?

[WesleySnipez]

Yeah, I checked them and those weren't the problem. I got a new O2 sensor, and the crankshaft position one has always been on cause of the egr. I cleaned the MAF (which didn't do anything) and then ran it with the MAF unplugged and it seemed to idle better and it didn't jerk or bog down. So I'm guessing its a bad MAF?

[PapaSmurf2k3]

its possible. Running without the MAF puts the ECU into limp mode/open loop operation.

Basically it runs off a very safe pre-determined map (and typically limits you to 2600 rpm or so).

[WesleySnipez]

Oh, okay. It didn't limit the RPM before. Just like goes to a certain point then bog back down to normal idle