SYTY will not idle.

[Don W.]

Re: SYTY will not idle.

Have you made any changes to parameter 7 in the chip? 10.0 might be as rich as the meter goes. You might actually be more rich that that. Is there black smoke coming out the tail pipe?

Grasping at straws a bit but, the injectors are hot all the time and the ECM just provides a ground.467 & 468 Green & Blue. are wires to the ECM C11 & C12 at the ECM Of the 2 large connectors it's the one with the fewest wires. If one of those wires is shorted to ground those 3 injs would be on all the time. If both were shorted I doubt it would even start but it might be worth checking. the connector is at the pas side rear of valve cover. Hard to get to, but then so is everything. Very unlikely but might worth it to check. For that matter if you have another ECM try that.

 

[v12powers]

Re: SYTY will not idle.

can you check the coolant temp .with your scanner koeo , then watch till full operating temp . sounds like you cts is junk .

CTS is around 60 deg celcius and I did unplug it to make sure it wasn't affecting anything.

 

[v12powers]

Re: SYTY will not idle.

Have you made any changes to parameter 7 in the chip? 10.0 might be as rich as the meter goes. You might actually be more rich that that. Is there black smoke coming out the tail pipe?

Grasping at straws a bit but, the injectors are hot all the time and the ECM just provides a ground.467 & 468 Green & Blue. are wires to the ECM C11 & C12 at the ECM Of the 2 large connectors it's the one with the fewest wires. If one of those wires is shorted to ground those 3 injs would be on all the time. If both were shorted I doubt it would even start but it might be worth checking. the connector is at the pas side rear of valve cover. Hard to get to, but then so is everything. Very unlikely but might worth it to check. For that matter if you have another ECM try that.

All of the settings on the chip are "stock settings" as far as I can tell. when you go into the menus you can add or subtract fuel and I have messed with it a little. but right now all settings are in the middle which is factory settings from what the instructions say. I have not looked at those wires at the ecm. but I will check them unplugged from the ecm with a multimeter and see if they reference to ground at all. I did inspect the injection harness and it all looked good before I put it on the truck. that's a good idea.

 

[Don W.]

Re: SYTY will not idle.

The harness thing is a shot in the dark. I actually doubt they are shorted to ground but.... Swapping the ECM itself has helped others in the past. Don't test the ECM term for ground. Just that the wires themselves are not grounded and while you're at it check for continuity. Unplug at both ends.

Grasping at straws again, have you used a different fuel pres ga to check that the first is reading correctly?

Maybe the coil is weak. Got another coil? Also the module in the dist. Might be worth changing that just to be sure.

 

[v12powers]

Re: SYTY will not idle.

An update. after checking all of your ideas out. and still having the same issues I looked to other sources creating the problem. As a total guess I dropped fuel pressure by 20 psi (guessing maybe the chip I have is not really scaled for the injectors I have, so dropping the fuel pressure down should simulate the injectors being smaller) and.... now it idles stable with an AFR around 14 to 15. and WOT at 11.5. so.... That's what the problem is. Thank you for all of your help and advice.

 

[Don W.]

Re: SYTY will not idle.

An update. after checking all of your ideas out. and still having the same issues I looked to other sources creating the problem. As a total guess I dropped fuel pressure by 20 psi (guessing maybe the chip I have is not really scaled for the injectors I have, so dropping the fuel pressure down should simulate the injectors being smaller) and.... now it idles stable with an AFR around 14 to 15. and WOT at 11.5. so.... That's what the problem is. Thank you for all of your help and advice.

Or the reverse, the injs are flowing incorrectly. Check their part numbers. Either way a great call.