86mazdarx7

My s4 6 port with t2 manifold that is ported so that the aux ports are always open started to fuel cut yesterday whenever i give it full throttle. I can rev it up but if i open the throttle alway the way i just get fuel cut. has ne1 had this happen or know wut it is?

geargrabber

i dont have any ideas to help you out, but i think i may have a similar problem.

mine happens randomly, and kinda rarely- at half-WOT the engine will just fall on its face then come back hard.

is that what it feels like when the fuel cuts?

--mike

JerryLH3

iTrader: (11)

It could be the ECU going into limp mode. Try pulling the error codes from the ECU.

86mazdarx7

i figured it out when i was giving it full throttle the throttle body was pulling on the tps wire adn it would short it out. I fixed it and it hasnt' done it yet

BlaCkPlaGUE

What exactly is limp mode? i've heard the term used a few times before, is it some kind of failsafe for overheating or something??

Bob_The_Normal

From what I've heard it's just a handicapped mode where it won't let you rev almost at all... more gas just bogs it down.

I'd guess maybe it starts inecting LOTS of gas, hoping that the unburnt gas will sort of lubricate the engine instead of it just running on no oil? And that in turn bogs the engine the more you try to rev, due to flooding.

Total guess, someone that knows will post I'm sure.

But I've also found out it is supposed to happen when the OMP is telling the ECU that it's dead. I don't think it happens for any other reason.

And relating to THIS thread... that sounds like a TPS dead spot, like he said... if you don't have a wire binding at WOT like he did, then I'd take an analog ohmmeter and test the range of the TPS. There is a bunch of threads that cover that... I think one is in the archive.

--Gary

HAILERS

No limp mode on a series four, only series five.

jerd_hambone

my 87 cuts fuel when at WOT in 4th gear

HAILERS

What rpm. Eight grand?

jerd_hambone

5k

HAILERS

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If it's a non turbo.......the car is busted. IF it's a trubo, you might be hitting fuel cut.

jerd_hambone

what do you mean "busted"? It only does that in fourth gear. if its in 5th it doesn't do that.