Alltrac with st215 motor running rich.

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Re: Alltrac with st215 motor running rich.

Postby underscore » Mon Nov 02, 2015 3:01 am

UtahSleeper wrote:Thing is, there are 2 intake temp sensors, from what I understand. One pre turbo and one on the intake manifold. I know I have 1 valid intake reading, but not sure which one.


Easy, unplug one and see if torque changes or not.
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Re: Alltrac with st215 motor running rich.

Postby CSAlltrac » Mon Nov 02, 2015 8:20 pm

I imagine you have already contacted Prime or Doug
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Re: Alltrac with st215 motor running rich.

Postby UtahSleeper » Mon Nov 02, 2015 9:08 pm

CSAlltrac wrote:I imagine you have already contacted Prime or Doug


Yes, prime has been very helpful, but I have not been able to call so not brainstorming.

I plan on trying the unplug idea tonight and see if I can use that to pinpoint a bad sensor.
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Re: Alltrac with st215 motor running rich.

Postby CSAlltrac » Mon Nov 02, 2015 10:10 pm

Have you played in boost yet? Im asking because in the build thread you showed some damage to the bottom side of the IC. If its leaking it could cause some issues for you.
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Re: Alltrac with st215 motor running rich.

Postby ___Scott___ » Mon Nov 02, 2015 10:31 pm

UtahSleeper wrote:Thing is, there are 2 intake temp sensors, from what I understand. One pre turbo and one on the intake manifold.

The reason for there being two IAT sensors is that the one in the manifold will "heat soak" during "pit stops," like a brief stop for gas and snacks. A heat soaked IAT sensor will provide erroneous info to the ECU and make the engine hard to start and it will run poorly until the IAT closes in on correct info. The pre-turbo IAT sensor provides more reliable info for that time interval, so the ECU will use it until the other sensor settles down.

I'll also note that speed-density systems are very tolerant of vacuum and boost leaks, since there is no "metered air." Systems that rely on an AFM or MAF are sensitive to air leaks because the ECU expects correct info from those sensors. In a speed density system, the ECU needs to know the intake manifold absolute pressure, the air temperature in the manifold, the engine displacement and a good estimate of the volumetric efficiency of the engine. With that info it can calculate the amount of air entering the engine and the amount of fuel to inject (I'm omitting a bunch of details of course.)
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Re: Alltrac with st215 motor running rich.

Postby UtahSleeper » Mon Nov 02, 2015 10:41 pm

CSAlltrac wrote:Have you played in boost yet? Im asking because in the build thread you showed some damage to the bottom side of the IC. If its leaking it could cause some issues for you.


Yea, I have played in boost. The second video I posted here has the torque readings when I am in boost. Not sure if the video will shed more light.

Also, I replaced the IC from before with a better condition one cause I wanted to rule out leaks or just crap caused by the IC.
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Re: Alltrac with st215 motor running rich.

Postby UtahSleeper » Tue Nov 03, 2015 1:03 am

Another small update with the troubleshooting I did tonight. This was with torque connected and engine running.

Disconnect MAP - Car died

Disconnected intake temp sensor on manifold - No change in output from ecu or idle.

Disconnected intake temp sensor pre turbo - intake temp changed to -40/nothing in torque. No other changes.

Disconnected sensor that has 2 vacuum lines going to it, on transmission side of motor - No change in output from ecu or idle.

Disconnected IAC - Idle went up, no other changes observed with load or o2.

Any other sensors worth checking? I know its not a very precise testing method, but figure of one of these sensors is feeding bad data then unplugging it should change what the ECU see's.
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Re: Alltrac with st215 motor running rich.

Postby UtahSleeper » Wed Nov 04, 2015 4:35 am

So, here is a question.

Do the st215's have an ECU that learns at idle/idle circuit? Or a circuit that just deals with idle? I know megasquirt has specific circuits that deal with idle and I know newer cars relearns, but not sure on these ECU's.

I also know that ECU's dont tend to be an issue, but just discuss.

I ask cause cause at idle is when I seem to be having the issues. Revving seems fine on the ECU and driving also seems to give the idea that things are fine. Its only idle.......from the data I can see.
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Re: Alltrac with st215 motor running rich.

Postby UtahSleeper » Sun Nov 22, 2015 10:57 pm

Well, here is another update with no solution.

Ran a compression check. All cylinders appear to be at 150 +/-. Seems low to me, but workable.
Removed the upper timing cover and moved the crank to 0. Both cam gear marks lined up with the back of the timing cover. This motor also had a timing belt done to it before, based on the additional purple markings on the cam gears.

This is what the plugs look like after about 50 something miles. Sorry for some blurry pics, but they all looked about the same.
Image
Image
Image
Image

And here is my previous emissions readings. My last check had about the same results.
Image

Also had my friend rerun an emissions test and the motor is still insanely rich. I averaged 10 mpg out of the last tank.

And here is a recap of everything else done with no changes in behavior.

-Replaced coolant sensor
-Replaced TPS
-Replaced MAP
-Replaced ECU
-Replaced O2 sensor
-Added fuel pressure gauge. At idle, reads 35 psi.
-Ran a fuel rail flush/injector cleaner

And as a quick summary of car:
-ST165 with Caldina engine
-DP from prime mr2
-eBay exhaust
-Walbro FP
-Straight intake
-Some random grounds added to the block

Are there any other sensors I should look at or any other troubleshooting I should be trying? Anyone have any electrical infor where I could verify data coming in and out of the ECU and sensors? Just frustrated cause she drives great and pulls hard(for my experience) but is running too rich.
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Re: Alltrac with st215 motor running rich.

Postby Tecker185 » Mon Nov 23, 2015 1:10 am

I would try another ecu. I had two caldina swaps. One of the ecu's made the car blow black smoke. It was like dumping fuel in.
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Re: Alltrac with st215 motor running rich.

Postby UtahSleeper » Mon Nov 23, 2015 3:23 am

Tecker184 wrote:I would try another ecu. I had two caldina swaps. One of the ecu's made the car blow black smoke. It was like dumping fuel in.


I have tried 2 so far, both behaving the same way :(
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Re: Alltrac with st215 motor running rich.

Postby zaluss » Mon Nov 23, 2015 4:29 am

Seems like everything has been ruled out. All I can think of at this point is either 1) wiring issue or 2) intake leak somewhere causing overfueling. Have you done a boost leak test? Vacuum leaks? etc
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Re: Alltrac with st215 motor running rich.

Postby UtahSleeper » Mon Nov 23, 2015 4:43 am

zaluss wrote:Seems like everything has been ruled out. All I can think of at this point is either 1) wiring issue or 2) intake leak somewhere causing overfueling. Have you done a boost leak test? Vacuum leaks? etc


Doesn't intake leaks normally cause lean conditions at idle? Also someone told me on a MAP type system, leaks don't effect it as much, is that true?

And back to your question, I tried before, but couldnt locate the leak. I only heard noise after I hit higher pressure, 10 psi. I will try again and maybe get a better idea.
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Re: Alltrac with st215 motor running rich.

Postby Tecker185 » Mon Nov 23, 2015 10:10 am

Have you ruled out a leaky injector?
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Re: Alltrac with st215 motor running rich.

Postby UtahSleeper » Mon Nov 23, 2015 3:24 pm

Tecker184 wrote:Have you ruled out a leaky injector?


I haven't ruled it out, but I figured it was unlikely with the spark plugs all looking the same and with how rich it is. Could 1 leaky injector cause a estimated 10 to 15 mpg drop in fuel economy? I am not sure what to expected from behavior if you have a leaky injector.
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