will not stay running

[cliffkemp]

I just rebuilt my motor. The motor was running fine before the rebuild with a maft and 3 inch sensor. I rebuilt it to fix some leaks that were an issue and just went ahead and did the whole thing.

I started it the other day and it will not stay on for more than about 10 seconds unless I hit the gas and keep the rpms above say....1800 or so. Anything above that, it will stay on until I let off the throttle.

Again, everything was working fine before the rebuild with on modification after the rebuild. I installed EMC link. I am still using the MAF and have everything set up according to the instructions. I have tried everything that I can think of. Would there be a specific reason why it runs good at around 1500 rpms and up and then, it just dies. It is as if the fuel was turned off. While it is running, it is a little rich. While running, it is around 12 or so AF/R and it is a 2.4L with 650 injectors.

Any help with this issue would be nice. I am not sure if it is something with Link that I am missing or, something else.

 

[2gTurBoD]

I just rebuilt my motor. The motor was running fine before the rebuild with a maft and 3 inch sensor. I rebuilt it to fix some leaks that were an issue and just went ahead and did the whole thing.

I started it the other day and it will not stay on for more than about 10 seconds unless I hit the gas and keep the rpms above say....1800 or so. Anything above that, it will stay on until I let off the throttle.

Again, everything was working fine before the rebuild with on modification after the rebuild. I installed EMC link. I am still using the MAF and have everything set up according to the instructions. I have tried everything that I can think of. Would there be a specific reason why it runs good at around 1500 rpms and up and then, it just dies. It is as if the fuel was turned off. While it is running, it is a little rich. While running, it is around 12 or so AF/R and it is a 2.4L with 650 injectors.

Any help with this issue would be nice. I am not sure if it is something with Link that I am missing or, something else.

Well your AF/r seems a bit off if thats your idle. Have you checked for boost leaks? How does it run for those 10 seconds? Are you sure you have your fuel trims set right?

 

[justinh722]

Could be a CAS problem. Make sure its plugged in all the way. Had the same problem. Did u get coolant on it at all?

 

[cliffkemp]

Well your AF/r seems a bit off if thats your idle. Have you checked for boost leaks? How does it run for those 10 seconds? Are you sure you have your fuel trims set right?

It never settles to an actual idle. While it is running, it runs around 1500 or so. When it runs for around 5 to 10 seconds, it is running fine but, just running rich. When idle starts to drop as the car is 'warming up' it just dies. I used the calculator on Link for the injectors.

If I push the accelerator, it will stay on until I let off, as long as I do not let off the pedal, it will stay on. As soon as I let off the pedal, it will start to settle to go to idle but, just turns off.

Everything ran just fine with the maft before the rebuild. I do not understand. The only difference between then and now is the installation of the chip and loading Link on my laptop. Link is controling the car now instead of MAFT and I ordered Link with the MAF adaptor to use the MAF and gave the translator to a friend.

Also, I have a spare computer that we put in just to see if it would run off of it. It stayed at 800rpms at idle with the non-eprom computer and without the translator hooked up. It did not cut off for what time we had it on. We did that to check to be sure the IAC motor was not bad. If it were a part that went bad, it would do it with either computer installed.

It does not make sense. It has to be something with Link from what I can tell but, not sure what it is.

Could be a CAS problem. Make sure its plugged in all the way. Had the same problem. Did u get coolant on it at all?

We did have to fix a pin on the CAS. It ran with the other computer that was stock with the car. The Link ecu runs good til it dies. It idles fairly high but, think cause it is not warmed up good. As the car warms up, it will die faster. It starts up fine and just dies unless you push the throttle. With the throttle pushed, it will run indefinately. So strange.

 

[justinh722]

Have u tried messing with the 0-100hz settings in the maf comp section of link? Had the same idle problems and had to move my sliders up until it idled. Have u checked for boost leaks?

 

[cliffkemp]

Have u tried messing with the 0-100hz settings in the maf comp section of link? Had the same idle problems and had to move my sliders up until it idled. Have u checked for boost leaks?

I have not changed any of those settings. I am new to tuning. I am a mechanical type of person. I just need to see something done and have it explained and, I usually get it. How will this help with the idle? Is there anything else in the settings that will help with idle other than the idle settings that, actually, did nothing from what I can tell with my car.

 

[justinh722]

Usually u can mess with the injector deadtime to help dial in the injectors. The set values it calculates are just a base setting. Try watching some basic tuning videos on links website to get some of your settings the same. Is ## BOV vented by chance?

 

[cliffkemp]

Usually u can mess with the injector deadtime to help dial in the injectors. The set values it calculates are just a base setting. Try watching some basic tuning videos on links website to get some of your settings the same. Is ## BOV vented by chance?

Yes, it is. It came that way though.

 

[justinh722]

Is the sensor installed before or after the BOV? It just sounds like u need to do a base tune by watching some vids to get your airflowperrev to around .28 and your combinedFT to around 0. You need to make sure the car is entering closed loop after it's warmed up and that your O2 sensor is cycling correctly. It's all in the videos on ECMtuning's site.

If your vented, make sure the BOV is installed before the GM MAF sensor. If it's installed after the sensor, u will be blowing off metered air and it will cause problems like your talking about. The best way to vent is with speed density.

 

[cliffkemp]

Is the sensor installed before or after the BOV? It just sounds like u need to do a base tune by watching some vids to get your airflowperrev to around .28 and your combinedFT to around 0. You need to make sure the car is entering closed loop after it's warmed up and that your O2 sensor is cycling correctly. It's all in the videos on ECMtuning's site.

If your vented, make sure the BOV is installed before the GM MAF sensor. If it's installed after the sensor, u will be blowing off metered air and it will cause problems like your talking about. The best way to vent is with speed density.

The BOV is before the MAF. Will it matter if the motor is a 2.4L vs. a 2L? At first, I thought it was the CAS, coolant sensor, and/or TPS but, put another computer in and it idled ok (did good since the maft is no longer there).

 

[justinh722]

Anyway u can post a log from link? Seems weird it works fine with one ECU and then won't stay running with the chipped ECU. Did u send it in to ECMtuning to get the chip installed? No leaky or bulging capacitors in the chipped ECU?

 

[cliffkemp]

Anyway u can post a log from link? Seems weird it works fine with one ECU and then won't stay running with the chipped ECU. Did u send it in to ECMtuning to get the chip installed? No leaky or bulging capacitors in the chipped ECU?

It is wierd. The chipped ecu was repaired a long time ago by the previous owner. He even gave me a spare ecu that is not epromed but, it did have the caps replaced as well. I did some looking last night and found the coolant temperature sensor was taped up.

I untaped it and found that one of the wires was completely broke in 2 and the other was frayed about 1 inch past the connector. I spliced both wires (make wire for a living) to the plug correctly, taped it up, and now, I am waiting on my rtv to dry as the kit I bought did not come with the little gasket or oring that goes where the thermostat housing meets the head...

I did notice that my O2 sensor does not cycle at all either (another issue but not sure if it is related to the coolant temp. sensor not working either)

I read that, if the computer has not had power to it for a prolonged amount of time, sometimes, it must relearn idle. I do not know how true this is. I also read that I could be experiencing some kind of fuel cut due to using the MAF sensor and, I do not understand that one either but, kinda makes sense in that it runs but, cuts off after 2 seconds. Sometimes, it stays on for up to 15 to 20 seconds. If I press the pedal, it stays on longer at times but, still dies sometimes as well.

The log shows timing is rather high as well. Timing around 2000 rpms was around 38.

Another thing....when running, my fuel pressure is around 30 psi. If I just turn on the pump when not running the engine, it is around 42 psi. When the car cuts off, the fuel pressure is around 30 then goes back up to 42 just as it stops....this would mean that the FI are being turned off or, the coil is being turned off, I guess. I will look at the log when I get the car running again this afternoon.

Is it possible that the coolant sensor is the reason for the cut? I can try to put the other computer back in as well to see if it will cut off with it as, we did not let it idle very long and may cut off to, if we had let it idle longer.

thank you for the help. I did watch some of the tuning videos and did get my TPS calibrated as it was only showing 80% at WOT.

 

[justinh722]

I think the fuel cut your referring to is when the idle gets too high it lopes. This is sometimes caused by a problematic or incorrectly adjusted throttle stop switch. Link has a option to check the idle switch. It should switch from 1 (no throttle) to 0 (throttle). The other fuel cut is when your driving in high boost in which the MAF and fuel take part.

The timing isn't usually a problem and will normally bounce around throughout the RPM range. The main concern for timing is around WOT. I have spots in my log where I'm at 25 degrees of timing with 2300 RPM and other times it shows 34 degrees around the same RPM.

Try to get your TPS volts to around .63 (if not already) with key on, engine not running. The coolant sensor can have issues with running rich but it doesn't sound like it's your problem. Just try messing around with the 0-150hz values in the MAF comp . It's not gonna hurt your engine. Raise the sliders up about halfway and see if the engine still dies. Your O2 isnt cycling because your combined fuel trims might be out of whack or its faulty. U need to get them on track by messing with injector deadtime and your MAF sliders.

You mentioned that your AFR's are off. Are you running a wideband O2 and simulating narrowband or do u have both the stock O2 and a wideband? See if you can post a log of the car running and dying so I can see what you have for settings. Fuel pressure should be set to about 37-38 PSI on a 1G with vacuum line unhooked. With Link, u can check the fuel pump to on and adjust the regulator with the engine off.

 

[cliffkemp]

I think the fuel cut your referring to is when the idle gets too high it lopes. This is sometimes caused by a problematic or incorrectly adjusted throttle stop switch. Link has a option to check the idle switch. It should switch from 1 (no throttle) to 0 (throttle). The other fuel cut is when your driving in high boost in which the MAF and fuel take part.

The timing isn't usually a problem and will normally bounce around throughout the RPM range. The main concern for timing is around WOT. I have spots in my log where I'm at 25 degrees of timing with 2300 RPM and other times it shows 34 degrees around the same RPM.

Try to get your TPS volts to around .63 (if not already) with key on, engine not running. The coolant sensor can have issues with running rich but it doesn't sound like it's your problem. Just try messing around with the 0-150hz values in the MAF comp . It's not gonna hurt your engine. Raise the sliders up about halfway and see if the engine still dies. Your O2 isnt cycling because your combined fuel trims might be out of whack or its faulty. U need to get them on track by messing with injector deadtime and your MAF sliders.

You mentioned that your AFR's are off. Are you running a wideband O2 and simulating narrowband or do u have both the stock O2 and a wideband? See if you can post a log of the car running and dying so I can see what you have for settings. Fuel pressure should be set to about 37-38 PSI on a 1G with vacuum line unhooked. With Link, u can check the fuel pump to on and adjust the regulator with the engine off.

When I first turn on the car, the timing says around 61 with the motor off. When I turn the fuel pump on, it says around 42, when the engine is off. I have the deadtime set to 200 and, I cannot get the TPS to show volts, just %.

When I did a run the other day, the only things it will monitor are basics. When I add new features for it by clicking on them and moving them to the right side, it will not show them at the bottom and assign a graph color to them like the basic ones have like timing, coolant temp, and others. I wanted to see the raw TPS to see what it is and, it will not show on the graph. I will try to do a run in a little bit and figure how to post it for you.

Thank you for taking to time to stick with this. There are no tuners in the area that know link very well. I will keep you posted and hope to have a run for you sometime today....I hope. Have to change some plugs on a grand vitara and figure out a coolant leak on my other dsm too. I have a talon and a laser. I love these cars but, they are frustrating at times.

 

[justinh722]

In ECMlink under the Edit tab at the top, it shows captured values and displayed values. The captured values are what link will log for you. All u need to do is go to the displayed values and mark which ones u want to show in the graph. Make sure u log BoostEST, AFRatioEST, TPSvolts, idleSw, injduty, LrnIdleAdj, CombinedFT, Airflowperrev, knockRet, Front O2, ISCposition, ThrotPos, RPM, and any others u want. Those are my main displayed values.

If your fuel pressure is 42 PSI with the pump on/car off, make sure you set the injector calculator in link to 42 psi also. According to link, your global should be -30.3 baseinjectordata [ECMTuning - wiki]
In this table for denso injectors that are 660cc's the recommended deadtime for a starting point is 180. If u look at the chart, u can see how the deadtime jumps from recommended 180 to 405 with 720cc injectors. What brand are your injectors? It varies between size and manufacturer.

Log the CombinedFT and see if u can get the O2 cycling by messing with the deadtime after u find the starting point u need. Try to get it within +5/0/-5. Try and display those values I told u about and see if u can't get some settings straightened out and see if thing's get a little better.

 

[cliffkemp]

In ECMlink under the Edit tab at the top, it shows captured values and displayed values. The captured values are what link will log for you. All u need to do is go to the displayed values and mark which ones u want to show in the graph. Make sure u log BoostEST, AFRatioEST, TPSvolts, idleSw, injduty, LrnIdleAdj, CombinedFT, Airflowperrev, knockRet, Front O2, ISCposition, ThrotPos, RPM, and any others u want. Those are my main displayed values.

If your fuel pressure is 42 PSI with the pump on/car off, make sure you set the injector calculator in link to 42 psi also. According to link, your global should be -30.3 baseinjectordata [ECMTuning - wiki]
In this table for denso injectors that are 660cc's the recommended deadtime for a starting point is 180. If u look at the chart, u can see how the deadtime jumps from recommended 180 to 405 with 720cc injectors. What brand are your injectors? It varies between size and manufacturer.

Log the CombinedFT and see if u can get the O2 cycling by messing with the deadtime after u find the starting point u need. Try to get it within +5/0/-5. Try and display those values I told u about and see if u can't get some settings straightened out and see if thing's get a little better.

Finally got it running today and, it stayed on once it warmed up. We had to hold the throttle open a little and, once it got up to temperature, I let off the throttle while my friend was messing with link.

It stayed on this time and we started getting the tune to work for idle but, we found another issue....I do not know how it did this but, the compressor wheel acts like it is locked up almost....The car may have ran for a total of 5-8 min from the time we put it together to the time I shut if off today. Oil was leaking a little from the head at the stock fitting cause I need to put new crush washers on it and, it is just barely leaking at the turbo feed so, I know it was getting oil before I was going to tighten it down anymore at the head or turbo. I do not get this....always something....the thing that gave it away was that if we blipped the throttle, it acted as if it wanted to die for a second. If we slow pushed the throttle, it would rev up. Before I go any further now, I am going to have to take the turbo off....again....and find out if it all of a sudden, went out or if something got in it....It worked fine boosting to 25 psi when we took the motor out....it was turning fine when I put the mani back on the head as we did not disconnect the turbo when we pulled the motor. It still has no front to back shaft play and almost no side to side play. I have another turbo that is similar but, it is the one with lots of lag and rated much higher hp and does not really suit the motor as it should. When I get this done, will get back with you about the tuning again.

Thanks again for the help.