Revolutions Posted June 2, 2019 Report Share Posted June 2, 2019 Hello and sorry for the long post. We have a V88 on an ls7 twin turbo Pikes peak hill climb car. We had issue last year when we twin turboed the stock ls7 crate engine. We hurt cylinders 2# piston multiple times and cyl #4 once (both cracked rings, and eventually cracked #2 sleeve). AFRs we safe and timing was very consertive but the AFR we not even between left and right bank. Almost a 2 point variance (gasoline scale). After replacing the engine due to damage, we started over trying to diagnose the issue. After trying multiple scenarios (swapping rails and injectors, coils, even rebuilt an engine harness using only the Vipec directions, never referencing the old harness) to no avail, we sent the ecu back to Link. Apon inspection they found that 2 injector mosfets we failing under the heat/distortion test. They were repaired with the newer g4+ parts and returned to us with a clean bill of health. Now, with the repaired ecu, the fueling issue is still present. Bank 2 is leaner than bank 1. In order to try to bring the afrs close, i have been using cyl trim to richen bank 2 by 10% and leaning bank 1 out by 10%. In total a 20% correction is needed to even get close to a mutual reading. All afrs have been verified by either swapping the in car 02s side to side, and also verified by a 3rd o2 i use consistantly on our dyno. With all these modifications and changes, i finally wired the ecu to accept a clutch input in order to use the launch control. Apon trying said launch control, it appears that only bank 2 is cutting ignition and retarding timing (pops and shoots flames only on bank 2 exhaust). I have contacted Link multiple times and have run thru all setting in the ecu more than once. They asked me today to send the map and a short log on lauch control but i have not been to work send it. Im am reaching out to see if anyone has any ideas on what to try. I have covered almost all bases more than once and im at my wits end. Pikes Peak hill climb is 4 weeks away and im feeling the pressure to not miss a second year in a row. Thanks for any and all input in this matter. Quote Link to comment Share on other sites More sharing options...
Adamw Posted June 3, 2019 Report Share Posted June 3, 2019 It was me that replied to your facebook message. I want to see your tune as there are some settings that could cause the behaviour you are seeing. To rule out the ecu here is one quick test you can do: Put the bank to bank fuel trims back to zero. At the ECU plug, swap the odd numbered injector wires with the even numbered, (the pins can be popped out easy without tools). Then give it another short run, if the lean bank moves to the other side then it is something ECU related, if the lean bank stays on the same side as it was before swapping injector drives then the problem lay elsewhere. Please attach your tune as soon as possible - even if you dont have a log yet. Quote Link to comment Share on other sites More sharing options...
Revolutions Posted June 3, 2019 Author Report Share Posted June 3, 2019 Thanks for the reply on both accounts. I will send the tune file asap. I am willing to switch injector pins as you suggested but im curious and a little confused on on how to correct for the inj output changes since it is a sequential setup. Wouldnt that mean i would have to swap injector connectors on each injector as well in order to keep them paired to the correct cylinder? I appreciate all the help i have recieved and really really dont want to start over with another system. I enjoy working with the Link system and run multiple cars on them. This one has been a struggle over the last 2 years. Thanks again for all the assistance. Quote Link to comment Share on other sites More sharing options...
Adamw Posted June 3, 2019 Report Share Posted June 3, 2019 8 minutes ago, Revolutions said: I am willing to switch injector pins as you suggested but im curious and a little confused on on how to correct for the inj output changes since it is a sequential setup. Wouldnt that mean i would have to swap injector connectors on each injector as well in order to keep them paired to the correct cylinder? No we dont care about perfect injector timing for a quick test. Dont worry about firing order or valve timing or anything - just swap only the pins at the ECU. What we want to do in essence is run the right-hand side of the engine with the injector drives that normally run the LH side. Actual sequential timing makes very little difference (well perhaps a little a idle but take it to some medium RPM when you check if the same bank is still lean). Leave the ECU set to sequential. Quote Link to comment Share on other sites More sharing options...
Revolutions Posted June 3, 2019 Author Report Share Posted June 3, 2019 I will do exactly that and also get you the file tomorrow. Again, appreciate all the help and assistance. Quote Link to comment Share on other sites More sharing options...
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