740 turbo cutting out at WOT

cr80442

Ive searched around and haven't found many people with the exact same problem as me. My car starts fine, idles fine, and cruises fine. Just if I'm cruising at say 60 and floor it. the car will bog and sometimes misfire then open up and then intermittently hit something like a fuel cut. My car isn't overboosting, my boost gauge shows what it should and I've checked the wastegate for splits. I have switched out the MAF from my 240 which runs fine and it hasn't changed. I think it's either my spark plugs wires, as the number one wire doesn't fully click onto the plug it just rests on it. I'm sourcing some replacement cords as we speak. Any ideas?

Limpzilla

Fuel pump/pressure or dirty filters?

cr80442

Fuel pump seems to be fine, when I first bought the car I used the inline pump on a switch to drain the tank and damn it worked good. Fuel pressure regulator seems to be good haven't really done any tests. I don't know about the filter tho.

Vee_Que

Fuel pressure can cause it, my wagon does similar things when I have a low tank of fuel. Especially if you haven't done any tests, you cannot assume anything.

But plugs are a big thing, copper only, iridium causes issues at low revs high load.

cr80442

Vee_Que;116444 wroteFuel pressure can cause it, my wagon does similar things when I have a low tank of fuel. Especially if you haven't done any tests, you cannot assume anything.

But plugs are a big thing, copper only, iridium causes issues at low revs high load.

I recently replaced the spark plugs with some NGKs so the plugs are good, ignition leads are next to replace.

Slowbrick

Could be spark blowout. Had that issue with my 240 with shitty top gun leads. Changed to bougicords and no more issues.

cr80442

Slowbrick;116456 wroteCould be spark blowout. Had that issue with my 240 with shitty top gun leads. Changed to bougicords and no more issues.

My car has really old looking boigicords. One of them doesn't even clip on the spark plug it just rests on it

UNM

Totally different environment, but my Honda CBR1000F had similar issues. I thought it was most likely fuel supply related (due to previous owners comments) , but in the end it was due to a weak/tired coil. Well worth checking that you are getting a good spark to all cylinders, especially at low revs when voltage is below normal levels.

A poor connection between lead and plug is a prime candidate for this behaviour.

I should add: check if problem is related to road speed, engine speed, or the change from cruising to WOT as that gives useful extra info