Alltrac with st215 motor running rich.

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UtahSleeper

Active member
CSAlltrac":d7ttz14m said:
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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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.
 
U

UtahSleeper

Active member
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.
 
U

UtahSleeper

Active member
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.
 
U

UtahSleeper

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


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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Tecker185

Member
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.
 
U

UtahSleeper

Active member
Tecker184":3hp8f5z8 said:
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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I have tried 2 so far, both behaving the same way :(
 
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zaluss

Member
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
 
U

UtahSleeper

Active member
zaluss":zigkqqan said:
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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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.
 
U

UtahSleeper

Active member
Tecker184":20g44wcw said:
Have you ruled out a leaky injector?
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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.
 
Z

zaluss

Member
UtahSleeper":230249cy said:
Tecker184":230249cy said:
Have you ruled out a leaky injector?
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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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I'm really starting to lean into wiring issue at this point. Have you reached out to Wiregap to see if anyone else is having this issue? I find it hard to believe that after swapping out the ECU, MAP, O2, etc that nothing has changed. The only consistent variable here is the wiring.

I didn't see it mentioned here but did you check the ignition timing?
 
U

UtahSleeper

Active member
zaluss":2wnpwsdt said:
UtahSleeper":2wnpwsdt said:
Tecker184":2wnpwsdt said:
Have you ruled out a leaky injector?
Click to expand...

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.
Click to expand...

I'm really starting to lean into wiring issue at this point. Have you reached out to Wiregap to see if anyone else is having this issue? I find it hard to believe that after swapping out the ECU, MAP, O2, etc that nothing has changed. The only consistent variable here is the wiring.

I didn't see it mentioned here but did you check the ignition timing?
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I haven't checked it cause I don't have the stuff to check coil on plug. I have read up on what I will need to do, just hard to extend the coil pack out with a top mount intercooler lol. Torque shows it advancing quite a bit when running thought.
 
U

UtahSleeper

Active member
Also I have emailed Doug at wiregap to get some troubleshooting ideas. Just waiting for a response after my last email this morning.
 
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UtahSleeper

Active member
So, I kind of quit updating this here. I have slightly more up to date info here

http://www.mr2oc.com/6-mkii-90-99-na-turbo/611281-st215-motor-running-rich-2.html#post6456762

Would like any suggestions on ways to test the harness while installed or any other ideas on why my car runs pig rich.

Recently had the injectors cleaned, but no change. They were no measured with specs, just had cleaners ran through and verified flow rate between the 4. All 4 were really close to each other.

Thanks for any input.
 
A

Andy

Member
A while back I helped Lamont out when he ws running rich....

http://www.alltrac.net/phpBB2/viewtopic.php?f=44&t=33578&start=210

But this was on a 185 engine, with an AFM... I think the 215 replaced the AFM.

The ECU pumps in fuel to match the air flow it being fed into the engine.

Thus, if the sensor which replaced the AFM is not working as if should, or there is a short in the signal wire, the ECU may be seeing a faulty high volume of air flow. It then pumps fuel to match it, avoiding a lean condition.

Jut my .02

Maybe you already did, but make sure the air flow measurement is accurate.

Andy
 
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UtahSleeper

Active member
Andy":2gcs35hc said:
A while back I helped Lamont out when he ws running rich....

http://www.alltrac.net/phpBB2/viewtopic.php?f=44&t=33578&start=210

But this was on a 185 engine, with an AFM... I think the 215 replaced the AFM.

The ECU pumps in fuel to match the air flow it being fed into the engine.

Thus, if the sensor which replaced the AFM is not working as if should, or there is a short in the signal wire, the ECU may be seeing a faulty high volume of air flow. It then pumps fuel to match it, avoiding a lean condition.

Jut my .02

Maybe you already did, but make sure the air flow measurement is accurate.

Andy
Click to expand...

The st215 uses a map sensor. I have tried to replace it with no change in results. The ECU(with torque reading it) shows my vacuum and boost from the ECU readings and they seem to always be close to what my mechanical gauge shows. So, I assume that is probably fine. In one of my previous videos the one thing that always stands out is that the fuel trim being read from the ECU seems to be trying to take fuel away. Obviously its not helping though lol.
 
B

bitter

New member
I know that you had your injectors cleaned, but are they the correct size injectors? Just a thought.
 
U

UtahSleeper

Active member
bitter":3rwvnzul said:
I know that you had your injectors cleaned, but are they the correct size injectors? Just a thought.
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They are the stock injectors by look(skinny and light blue). Look identical to ones I have seen for sale.
 
3

3SDNA

New member
UtahSleeper":pnqvnoc8 said:
Bump. Still accepting suggestions. Also, any good write ups on testing a harness?
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When I got my Caldina swap running, I was having this same issue, but I ended up replacing the water temp sensor for the ECU, and that fixed it.
 
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