Nate79

Hi guys I have a 91 sc400 with a dead right bank, it has new plugs, compression 160+ fuel to the fuel rail, spark seem fine. It seems to run the same with or without the maf connected, iac valve is open but stalls if I block it off, have done a resistance test on maf which gives 4ohm at 13 degree.
Anyone have any advice? Thanks

Tallyhoe

Besides dead, maybe I'm a little thick, but is it a misfire? Assuming the assembly is rotating as you're able to get compression out of Bank 2. Or are these Bank 1 numbers? Are there any other maintenance issues with it? Just trying to get a base explanation on what it going on, for somebody to better assist you.

RudysSC

Have you pulled a plug and verified spark? It could be a dead ignition coil to that bank or an issue with the distributor for that side... That's about the only thing I can think of for why you'd be down an entire bank but maybe someone else will have another idea?

Nate79

Hi yes it is running, compression done on all 8, all eight leads are sparking, if I pull each lead when running all 4 on one bank cause motor to die but the other 4 do nothing, it has twin pipes and the right exhaust is running cold cheers

Nate79

Well yeah I thought something like that but since each coil feeds 2 cylinders on each bank I figured the coils must be ok and I have moved leads around are they make no difference cheers.

Tallyhoe

Head scratcher here. Have you tried swapping ignitors to see if it switches sides? At this point wouldn't hurt to try to see if it's mechanical. If it isn't, maybe it's time to dig into the wiring aspect of it and ensure there is no damage in other pertinent sensors to the ECU. Maybe a damaged ECU, but i would assume the symptoms would be more randomized to both sides.

Nate79

Hi thanks for that I will try swap the ignitors I have just had the ecu rebuilt by a soarer specialist so I would hope it's not that but it has a 12 month warranty so if all else fails I will send it back.

RudysSC

Thanks for the extra info... Definitely an odd one here. I think swapping ignitors is a good idea to make sure it's not something bizarre going on. Otherwise, if the ECU refresh is new and the issue came up after it may be worth sending back to make sure something didn't get soldered somewhere it shouldn't have...