P0340 Post HG (1 Viewer)

[Riad]

I was hoping some one has experience with this . I am now consistently getting this code. The truck fires up fine but the idle is really rough and pretty much has all the symptoms for a Camshaft Positioning Sensor circuit malfunction. CEL comes on after few seconds of idling. Idle drops from 650 to 100. I understand the problem domain includes wiring, ECM, Open/short in Camshaft Positioning Sensor circuit and even in the circuit itself. I have cracked the Crankshaft Positioning Sensor under the #1 oil pan while I was putting it on. Ordered a new one from Dan, (Well Antonio). Could that be causing a short? Did any one experience this after a HG job?

Any information and/or suggestion is greatly appreciated.



-Riad

 

[Ruadhrigh]

I had the same code coupled with a P0120 (Throttle Position error).

I had removed the Throttle Position Sensor when I was cleaning the throttle body. When I put it back I put it on wrong. In the FSM it says to adjust the TPS to 10. This is done just like the distributor. Losen the two screws and rotate it till you reach 10. The TPS number is displayed on the Scan Gauge (another reason to buy the Scan Gauge).

When I corrected the TPS the P0340 dissapeared.

 

[Riad]

Thank you!

I don't get any other code though, just 340. I did not remove the TPS when I removed the TB.

You mean 10 * (degree) right? I'm gonna give that a try tonight.

Thanks Again

 

[Ruadhrigh]

Ten was the number displayed on the scangauge. I don't know that it related to degrees. I think the FSM wants you to plug in a fancy OEM ODBII reader, but the SG works just the same.

 

[Riad]

I wish I could get the SC some where local. I am wondering, why would I only get code P0340 instead of P0120 or combination of both. I am afraid to screw up the TPS if there's nothing wrong with it. FSM only talks about troubleshooting the Distributor related things for P0340.

 

[Riad]

Well found some thing but not sure what it is, yet. There's a buzzer/static sound comes from under the top air intake intake chamber every time I turn on the ignition. It only happens when battery cables are disconnected for few minutes and reconnected again. Had the wife turn on the key this time and I was leanning on the air intake chamber with both my hands on it. I felt the vibration with the buzzer/static sound.

I thought I connected every thing under there, there are only 2 cnnectors under there. Any idea any one?

Thanks

 

[Riad]

It's the IAC valve sensor on the TB that sort of chappers or buzz when the ignition is turned on after the battery is connected. Seems like I am on my own on this. Did about two hours of reading late last night. Considering replacing the Engine Wiring harness. If I can't figure out or find the short I might just do that. My last resort is to tow it to a repair shop. I really don't wanna do that.

Every thing checked out fine mentioned in this thread. My situation is more close to scenario 3 mentioned in the thread, except the truck starts up with very low/rough idle.

 

[Jacques Villeneuve]

How long do you let it run?
Can you take it for a spin and see if the ECU "self adjusts" ?

 

[motorsargeT]

Before you really start digging in to this I would wait until you get your new crank sensor in. The crank sensor is what the cam sensor checks itself against for a reference signal and if it is a bad signal it may throw the wrong code. did it do this immediately after the HG replacement? Maybe the cam timing is off? I will not admit to being an expert on the 1fz-fe but I do know a whole lot about diagnosing problems on vehicles. Get the new crank sensor in and check back.

 

[Riad]

I let it run for a minute or two then I shut it off. I am afraid to through a rod or some thing more serious as I don't really know the real consequence of letting it run like that. The idle is really low, it wants to shut off but stays up and running. I pressed the gas few times to get the idle to normal but then white strong gas smoke starts to come out the exhaust. Absolutely no leak no where can be found in the engine. Right now I filled up the radiator with water and coolant flush solvent as I was planning on flushing that. I am not sure if I can take it for a spin like that, I wish I could though.

 

[Ruadhrigh]

I have cracked the Crankshaft Positioning Sensor under the #1 oil pan while I was putting it on. Ordered a new one from Dan, (Well Antonio) -Riad

did this part come in? were you able to install the sensor?


and what is the IAC? Is that the black connector closest to the passenger side of the TB?

FSM only talks about troubleshooting the Distributor related things for P0340.

Is your timing adjusted correctly? Maybe the distributor is rotated too much? I do remember before I used the timing gun that rotating the distributor too much would give me an error code (I can't remember exactly but I think it might have been the P0340)


I am not trying to second guess your work, just trying to keep you from paying a mechanic for something you can do.

 

[Riad]

did it do this immediately after the HG replacement?

Yes. The CEL did not light up immediately rather it came on after I pressed on the gas and tried to get the engine to warm up with rough idle.

 

[Riad]

The IAC sensor is the black round looking sensor right beside the throttle positioning sensor in the throttle body. I haven't checked the timing with a light yet. I am going to ASAP but I did all the other things like: align the (one and two) dots in the camshafts with the head surface horizontally in a line. Rotate the crank pulley clock wise so the groove on it precisely matches with 0* and the the #1 and #6 pistons are TDC (I did this before I put the head on). And finally ensured that the distributor rotor pointing to #1 plug wire. I guess timing can be off no matter how meticulous I was on doing this. I took about a month and half to get this done so I tried my best to avoid any mistake. But as this is my first time, I may still have made some so feel free to second guess my work .

 

[Ruadhrigh]

We followed the same path for putting our trucks back together. And my timing was off. It is a simple thing to do though. I bought a cheap timing gun and it was a very simple procedure.


If you are at home you can try this:

loosen the distributor bolt. while idling rotate the distributor, turn it towards the cab and you will advance the timing. (higher idle) then check your dash to see if the light is still on.

 

[Riad]

Thanks a lot! I'm gonna try this as soon as I get home.

 

[alia176]

Do check the grounds in case one was left off by accident. Just my .02 cents!

 

[Ruadhrigh]

Do check the grounds in case one was left off by accident. Just my .02 cents!

you don't need no stinkin grounds!




Just kiddin, it is a good thing to check. There are three that you would have taken off: fireall to exhaust side of head, front engine hook, and the intake has one.

 

[NaterGator]

Riad did you score a mark on your distributor so that you know how to align it rotationally when you reinstalled it? It seems like it pivots around its axis so that you can sorta fudge the spark; maybe you oriented it differently and it's off now?

Edit: I need to read the replies more carefully, I see this just got covered...

 

[Riad]

you don't need no stinkin grounds!




Just kiddin, it is a good thing to check. There are three that you would have taken off: fireall to exhaust side of head, front engine hook, and the intake has one.

I thought it's two ground wires, not three. firewall to exhaust side of the head is one wire. And the other wire is from the Engine Hanger to the intake. Am I missing a 3rd ground wire?

 

[Ruadhrigh]

I'm pretty sure there are three. My truck is at home so I can't go look at it right now.

The third comes up from the wheel well and connects somewhere to the intake manifold... I think...


I'll check for you when I get home.