THIS LOW RPM ENGINE STALLING SAGA POSSIBLY SORTED

[Guest <NIS_02>]

ok then Mr Mark0

[cowboyb]

My ECU is the LT12 (for R33). Sold to me by RPM (Sth Aust). Theyre a distributor who sent the ECU back to manufacturer (in Vic). According to RPM, the ECU board was not assembled correctly causing some electrical issues in it. Once 'fixed' and sent back, RPM retuned the ECU to suit my car..and all is well...except for the "drop in fuel pressure" problem.

I suggest you have your mechanic clean up your car's idle solenoid valve...it could be dirty. And then have the ECU retuned.

[R31Nismoid]

Hey People.

I had an R31 ... sold it to but another R31 but a GTS-R

This one has an RB25DET in it and it has exactly the same problem.

If i hit the clutch in 2nd or 3rd... after driving hard or slow...

The cars revs don't just drop.

It 99% of the time stalls. Unless i get the next gear up or down.

How does that work ?

Cause i don't have the R33 pump setup (i don't think i would anyhow)

This is weird !!!

ALSO i get this whiff of fuel a bit often.

Any ideas where i might come from :confused:

Any help much appreciated

[rs73]

my car could almost stall if I turn on Aircond and come to an idle when slowing down. It will drop to like 500rpm, almost stall and comes back again... this happen only when the aircond compressor is working on. when the compressor is sleeping (when it reaches the desired temp), there's no problem. And of course no probs when aircond is off...

would only happens to me during this summer season. I think I can live with it for 3-4 summer months

[Guest Lojikl]

Well I thought it was just me with thuis wierd problem in my new R33

Ok, so it looks like i'll have to try the fuel pump.

What are the implications of the fuel pump running 100% all of the time. (I don't really know what this means)

Anyone seen what the other solutuion to the problem is?

Thanks guys.

[PSIKO]

not sure if it's already been mention and was hidden in one of the posts, but the reason behind earthing the pumps ground wire directly after the pump, is that it bypasses the ecu

normally, the earth wire goes to the ecu, and it alters the pump speed to compensate for the amount of air being introduced.

By earthing it straight out, you are running the pump on it's maximum speed

which introduces a new problem:

IF YOU HAVE A STANDARD PUMP AND YOU ARE BYPASSING THE ECU PREPARE TO BUY A NEW ONE SOON since you'll burn the older, smaller and less efficient one out very quickly

apologies if this has already been said though!

[Guest Lojikl]

Excuse my ignorance, but,

Does running the pump at 100% cause an extremely rich mixture, if the ECU isn't controlling the speed.

??

[PSIKO]

nope, the fuel will go back to the tank via the return line

I did it on mine to keep the fuelling up on changing gears, but also helps out stalling effects

[Guest Lojikl]

Cheers,

Off to find me a new fuel pump.

[GTS-t VSPEC]

Lojikal,

The fuel pump always pumps the same amount regardless, whatever is not used will return to the tank. By placing a fuel pressure regulator you can adjust the pressure at the fuel rail, and can increase the delivery of fuel from the injectors. These fuel regs. are rising rate, which means that the more boost the higher the pressure.

See'ya:burnout:

[PSIKO]

paul: the pump only pumps what the ecu tells it

the main advantage of earthing the pump and causing it to pump at it's max speed, is that it helps with stalling

but also when changing gears the afm sends a signal to the ecu, saying it's not being told to suck air in (not boosting - changing gears), so the ecu tells the pump to slow down, but then when you get back onto the accelerator the pump has to flick back up to full speed ... you therefore get a large amount of fiddling and a 'step-up' feel from the pump (minor loss of power)

with the pump engaged at full all the time, the fuel is still being pushed through ready to ignite with the changing air, and not being tripped about by the ecu

sorry if this isn't making any sense (even though I'm english, I can't seem to express things properly )

[Ait]

It's another gremlin problem!

[Baby Zilla]

Hi Guys,

I have a very similar problem with my 1993 Nissan Skyline R33 GTS-T.

Thank god I am not the only one experiencing these problems!

Everyone else I have tried to explain this too has looked at me like I am some sort of moron!

The problem I am having is quite difficult to explain. I'll be driving along normally with the throttle open and then all of a sudden the revs will drop and the engine will stall. It's like the throttle just cuts out. I can have my foot flat to the floor and the revs just drop and the engine cuts out. Could this be due to the fuel pump issues mentioned previously?

But, if I then turn the ignition off and restart the car, it will continue on driving normally until of course, it happens again!

I can also sometimes bring the revs back up by depressing the clutch and engaging gears again.

This previously happened every trip I made in the car without fail-very dangerous!!!

I have reset the ECU several times, and the car generally will then go for weeks without it happening, but, will all of a sudden start to occur again.

It generally happens after I go over a large bump, or when I change gears. It has also ocurred several times when I have activated my windscreen washers. It also tends to happen more often in hot weather.

It also has a tendency to happen when the car is at idle or when engaging the clutch when pulling up at lights.

It has also happened regularly when when I slam the door shut whilst the turbo-timer is running.

I have had the car dyno-tuned twice and the plugs replaced in an attempt to solve the problem. I think I may also be having problems with a leaky BOV. Could this be contributing to the problem in any way?

I have asked several auto-electricians to look at it, most have refused because they know nothing about them, and one told me that there is no such thing as re-setting the ECU and that it is a waste of time!

I have even taken it to Nissan who basically told me all self importers are scum and to go jump!

From my very limited knowledge of cars, I feel it is probably an electrical fault, fuel problem, or, diagnostics issue, but, I really don't know. This problem is very frustrating and also very embarrassing when it happens in the middle of an intersection-not to mention dangerous.

It has been suggested to me that it could either be an airflow problem, a problem with the crank angle sensor, or, a problem with the ignition regulator/modulator, but, the mechanic I have been taking the car to has so far been unable to fix the problem.

Obviously I am not too happy with this and was hoping someone could recommend a reputable mechanic/workshop/auto electrician in Melbourne that specialises in or at least has a great deal of experience with R33 Skylines.

Any further advice you could offer me on this issue would be greatly appreciated.

[dAVE]

any info on how to do this on a 33?

[R31Nismoid]

Baby Zilla.

I'm in melb and i had the same problem with my R31.

The root cause of the problem was loose wires from the ECU eatrhing out on the car body intermittently.

Have a look at the loom right near the ECU inside the car...

And look for where S-AFC's and the like would be plugged in and see if there are wires that haven't been soldered/taped up properly.

Then if it still continues after it's all been looked at (dr_drift did it for me and was a great help)

Then it would be the CAS.

Go and get that changed...

I talk form expiriance there. Mine had the same problem for over 8 months and i took the bloody car here, there, and every where!

[Baby Zilla]

Nismoid,

Thanks for your advice, dude.

Will get it looked at ASAP!

By the way, I see you're from Tulla, but, where is Dr Drift located?

Cheers

[R31Nismoid]

essendon area

[Guest Ellwood]

You guys are silly.

[R31Nismoid]

Oh yeah...

and ?

[Ait]

Yeah sort it out with the Dr..he knows his stuff.