Running fault during dyno tune
#1
Running fault during dyno tune
Hello from across the pond
Okay I've got a strange problem that I need help with. Basically the car is a race car and has just had a full engine rebuild, little bit of head work, fitted with a T28 Garrett turbo, MiataLink ECU, 600cc Deatchwerks Injectors, Large intercooler. ETc ETc.
Now the car was on the dyno being tuned and all is well, apart from after a high rpm run when the clutch is dipped and engine idle's it drops to 3 cylinders (sometimes 2 cylinders) and then slowly picks back up to 4 cylinders. If the car is loaded back up on boost on 3 cylinders it clears and pulls like a train on 4 cylinders. It sometimes drops cylinder 1 and sometimes cylinder 2? But not 3 or 4?
Can anyone point me in the right direction of the problem.
Cheers.
Okay I've got a strange problem that I need help with. Basically the car is a race car and has just had a full engine rebuild, little bit of head work, fitted with a T28 Garrett turbo, MiataLink ECU, 600cc Deatchwerks Injectors, Large intercooler. ETc ETc.
Now the car was on the dyno being tuned and all is well, apart from after a high rpm run when the clutch is dipped and engine idle's it drops to 3 cylinders (sometimes 2 cylinders) and then slowly picks back up to 4 cylinders. If the car is loaded back up on boost on 3 cylinders it clears and pulls like a train on 4 cylinders. It sometimes drops cylinder 1 and sometimes cylinder 2? But not 3 or 4?
Can anyone point me in the right direction of the problem.
Cheers.
#6
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Sounds like an injection problem then - try to pull one injector connector off (cyl 1 or 2 - whichever one is not firing) and see if that changes behaviour. Either something is faulty inside the ECU (injector drivers) or the injectors themselves are whacked out. For starters you can swap injectors between cylinders to see if that changes the pattern (move 1+2 in place of 3+4). If the cylinders affected are now 3 and 4, you need to check your injectors.
#7
Sounds like an injection problem then - try to pull one injector connector off (cyl 1 or 2 - whichever one is not firing) and see if that changes behaviour. Either something is faulty inside the ECU (injector drivers) or the injectors themselves are whacked out. For starters you can swap injectors between cylinders to see if that changes the pattern (move 1+2 in place of 3+4). If the cylinders affected are now 3 and 4, you need to check your injectors.
It just seems odd that it sorts itself out after idling for little while and has no effect when load/boost is applied.
It also seems to get progressively worse, ie the first run it would be fine, second run it would drop a cylinder but come back quickly, third run maybe take longer to come back and then maybe drop two cylinders the next time.
#8
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Location: Athens, Greece
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Sounds more like injector drivers then. You can confirm this if you have an oscilloscope - if you probe the two pins on the injectors while idling, on the faulty cylinder, you won't see injection events.
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