SRT4 Lopey Idle

[strang3majik]

Hey guys, I just bought a 2005 SRT4 blown up and I had this PT Cruiser Turbo engine sitting here ready to swap in. Didn't get any responses on SRTforums so I figured I'd try here.


Anyhow, I swapped the engine in and got it running. Car runs excellent, pulls smooth, starts up easy...however:

At idle it has an occasional lope to it, enough to make the engine rock back and forth some.

I have no check engine lights and I've probably put 200 miles on it so far. I do have a battery light for the battery temperature sensor, could that have anything to do with it? Its charging fine and the battery tests great.


Compression was about perfect: Cyl 1 - 170, Cyl 2 - 170, Cyl 3 - 165, Cyl 4 - 170

So my thought are maybe the timing belt could be off a tooth (I did install a new one), or maybe there's another issue. I was thinking with the mods maybe its running very rich? Cams are stock.

At idle it pulls between 14-18in/vac depending on if the idle is smooth or rough. When it smooths out its between 16-18.

But no Check engine lights, only the battery light.

Any ideas? My last car I got the timing belt off and a Cam/Crank Synchronization code came up. This car has none. Kinda at a loss since there's no CEL picking up anything wrong. Just trying to get other simpler ideas before I go ripping it apart to check the timing.

New upstream o2 sensor as well.

Mods are...

Stage 2 MAP
Stage 2 TIP
k&n cai
Aeromotive fpr set at static 58psi
Perrin fuel rail (with a return system?...thought that was stock)
Stage 2 injectors
Stage 1 ECU
3" turbo back
Aftermarket tb
Greddy Type S
Agp intercooler
Agp wastegate
180* Thermostat


Any ideas would be awesome. Car seriously runs excellent...I have it set at around 13/14psi until I get everything squared away.

[A.J.]

If your exhaust cam is off a tooth or two you won't set a code, the sensor is on the intake cam. What injectors did you use, Neon or PT? If you used the PT injectors, letting them sit could have gummed them up.

[strang3majik]

They're SRT4 stage 2 injectors.

And I guess I'll have to check it. :/ I hate getting to the timing belt on these things...ugh. The 2.2 setup was so much better...haha.

[A.J.]

I did my SRT-4 timing belt on an engine stand and still messed it up. Doing it in the vehicle is even worse. I don't like the factory marks, they are too easy to mess up so I get everything at TDC and lined up and make my own marks on top against the timing cover with a white paint marker.

[Keito]

Are you using a Diablosport tuner to compensate for the stage 2 injectors/TIP and MAP sensors using them on the Stage 1 computer?
Your tune is off if you just installed the parts with no tuning.
Also the fuel system is returnless in stock form.

[strang3majik]

Are you using a Diablosport tuner to compensate for the stage 2 injectors/TIP and MAP sensors using them on the Stage 1 computer?
Your tune is off if you just installed the parts with no tuning.
Also the fuel system is returnless in stock form.

No...I bought it with all these parts on it...I just swapped everything over to this engine. But its a 2003 stage 1 ecu. Car is an 05...they dumped the stock ecu since 05s have the overboost code. I was wondering if the injectors/sensors would cause issues but it was running before...though they did have the boost set to pinning the stock boost gauge levels.

And ok...it has a return system on it now.

Also, I put the timing belt and water pump on while the engine was out of the car...I turned the engine over probably 10 times and it was perfect...was a pain getting it there but it was perfect. I can't believe it would've changed but idk.

[Keito]

The MAP is scaled different, it's a 3 BAR so that's definatly an issue. The ECU is seeing less boost than it's running.
In your case it would be easiest to buy a DS Predator and get a stock stage 2 tune loaded on it for the sensors, then you could do additional tuning from there.
That or replace the Stage 2 components with stock parts. I'd say the injectors are making it run rough.

[shackwrrr]

03 stage 1 ecus are pretty much identical to later stage 0s, along with the larger injectors you are dumping in too much fuel. You are probably getting the lopey idle when in open loop.

[CNH320]

What Keito said. Swap back to stock injectors and MAP/TIP as the stage 2 parts are not made to run with the stock/stage1 tune. If that fixes your problem your cam timing is probably good but you can't diagnose that with wrong parts installed for your tune.

[strang3majik]

Well...my problem is I bought the car with these parts installed. The previous engine threw a rod through the block...but when I put everything together they had the wastegate hooked up incorrectly. Being its aftermarket, they had it setup to be computer controlled...but it would pin the boost gauge, so I have it with a direct line and running at the wastegate spring level at 12 psi.

I don't have any of the stock parts though. The car does seem to be kinda rich...especially since fuel mileage isn't that great. But it runs smooth as silk...just idles kinda rough sometimes.

Only thing I do have is the original 05 ecu. Not sure if that would be any different if I swap that in???


But how the hell am I not getting a check engine light! :/ Also, when the a/c is on, its pulling 10 in/vac. Seems awfully low to me...which makes me think timing.

But then sometimes it'll be at 16-18.


Is it safe to drive it like this in the mean time til I can afford a Diablo sport tuner? Like I said, I have it set down to 12lbs...

Also...the turbo flutters quite a bit at partial throttle. I've read its due to the AGP wastegate, as the stock computer controlled doesn't allow it to build boost til a certain rpm. Any ideas there?




This is why I hate buying cars with aftermarket parts already on them. But hey...my first SRT engine swap and it runs with no CELs...lol

[Keito]

There's no CELS but the data the PCM is reading from the sensors is incorrect and it still thinks there are stock injectors installed.
I think 10-12in/vac is normal at idle, it supposed to finally stop raining here in Ohio tomorrow so I plan on driving my car, I'll check it out.
AGP wastegate is great for more boost but not good for normal driving.
I normally get 23-25 mpg/ tank with a few WOT blasts, you should be no worse than that.

[INVUJerry]

If the exhaust cam timing is off you won't get a CEL since the cam sensor is on the intake cam. Easiest way to check is get it to TDC and see if the dowel holes line up on the cams.

[Force Fed Mopar]

The battery temp sensor is actually an ambient temp sensor. It could be throwing things off if it's going bad.

[strang3majik]

Keito, thank you, if you could. I just know 2.2s usually pull a bit more than that. And I'm pulling the upper timing cover off today. If its a tooth off at the crank it would throw a code right?

And I was thinking that about the batt temp sensor. But I read its only for charging. But it's the only code I have.

P0517

Though what I've read, 2005 didn't have this sensor. Being I have an 03 stage 1 ecu that's why I'm getting the code. Supposedly. And supposedly that's the only bad thing is the batt light comes on. Kinda annoying. :/


And yea I'm see that about the agp. Turbo surges light crazy at partial throttle. Blip the pedal instant 10psi

[rich tideswell]

And I was thinking that about the batt temp sensor. But I read its only for charging. But it's the only code I have.

P0517

Though what I've read, 2005 didn't have this sensor. Being I have an 03 stage 1 ecu that's why I'm getting the code. Supposedly. And supposedly that's the only bad thing is the batt light comes on.


2005 cars did not have the battery temp sensor, why they changed this for the last year is anyones guess. 2 fixes for this: find a stage1 or stock PCM for a 2005 car (VIN would have to be flashed in either case), or wire up the battery temp sensor like the 2003/04's have.

[Keito]

No Prob.
I never had one but everyone complained about part throttle boost with the AGP
I have a PTP actuator but when you go to DSP you'll want a stock actuator, the DSP works best with that

[strang3majik]

Here's a video of the boost gauge. I did just swap the MAP sensor out for a stock one (Found one in the box o parts I got with the car). I double checked the part number and it is a stock one.

Anywho...car seems down on power now. I unhooked the battery and all. But other than that, seems the same. I double checked the plugs and compression today...perfect as it was last time. Same exact compression numbers.


But here's a vid of the boost gauge so you can see what its doing. First with the a/c on, then the clicking is me turning the a/c off where it goes kind've normal, but still jumps around...and when its jumping like that, I can feel it in the car. RPMs look solid though.

http://i620.photobucket.com/albums/tt282/strang3majik/th_IMG_21991_zps185856d0.jpg (http://i620.photobucket.com/albums/tt282/strang3majik/IMG_21991_zps185856d0.mp4)

[strang3majik]

After putting the stock MAP sensor in and driving it around, it runs horrible. So, I'm putting the 3 bar back in it. Any chance someone flashed a tune onto this Stage 1 PCM for all that stuff and just didn't give me the tuner?

But anyhow, checking cam timing today with a straight edge...I'll post a pic when I do.

Also, did a calculation for fuel mileage...getting about 17/18 with mostly 70 mph cruising around these parts. Something is definitely not right.


If cam timing is on, I'm throwing the stock ecu back in it to see if that does anything.


I think I know why the last engine threw a rod.

[84omni]

To fix the battery light being on you just need to wire in a 10k ohm resistor in place of the sensor. That's what I did when I relocated my battery to my trunk. I get around 27-28 mpg with mine but its a big turbo car.

[Keito]

You were right, 18-20 in/vac at idle
I don't think the MAP would make it run rough, the tune would be off, (rich/lean) because of the MAP scaling
Could someone have put a tune on it scaled to the sensors, sure.
I'm not sure of any of the newer tuners available, but the DSP needed to be "married" to the PCM, meaning once the DSP is plugged into that car, the DSP can't
work on any other car until the tune is unloaded from the DSP
If you're going to swap stuff out, I think you need to start from scratch with the stock MAP,TIP, PCM and injectors, then see if it still runs rough

[strang3majik]

Cam timing is off. :/

http://i620.photobucket.com/albums/tt282/strang3majik/image_zps840d1dce.jpg (http://s620.photobucket.com/user/strang3majik/media/image_zps840d1dce.jpg.html)

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and thanks for checking that Keito...I thought the vac seemed low...this would definitely do it.

I know exactly what I did as well, because I can get them to line up perfectly, but they're not going with the tilt of the engine, I did the timing with it sitting flat on the ground. So my fault entirely.

Makes me excited for how well she will run though...with the timing that far off, thing ought to be a beast with it right on...haha.


So tomorrow's project.


But would you guys recommend sticking with the 03 Stage 1 ECU and wire in the resistor like 84Omni said, or stick the 05 ECU back in?

And I'm really not wanting to have to buy all stock sensors and injectors just to put the Stage 2 stuff back in once I then save up for a tuner...lol. But I want to pick up a wideband and until then I'll keep the boost low and take it easy on it. If anything, I would think it would be running a little rich which should help make it a little safer to drive...I'll just keep an eye on my oil, make sure its not getting washed out.

But I'll keep you guys posted once I get the timing squared away. Not looking forward to pulling the crank pulley off and getting that bracket out again...but, live and learn.



I need to stop getting projects...poor Omni will never be done :( Lol.

[strang3majik]

All better. Was off a bit actually. Its right on now...checked it with a straight edge...lol

But she's running flawlessly. Now to get a set of shift cables and a tuner and boost away :)



I hate how these cars feel like they're going so slow, though. Just cruising along, look down, 90mph. The hell?