R34 Gtt Sometimes Hard To Start

[samtaylor]

Hello all.

I purchased a 2000 model r34 GTT and since buying it, have noticed that sometimes the car will be quite difficult to start.

It is a little hard to explain but I'll give it a go.

When I start the car in the morning, the engine will start straight away.

Sometimes I will turn the key and it will keep turning the engine for maybe 10 or more seconds before finally kicking over and idling very low to begin with, but catching the proper revs and the car will run fine.

Some days I can start the car fine, turn it off, start it again and will be perfect. Other times it will start fine, then take ages later on in the day.

I replaced the fuel pump from the standard unit to a Deatchworks DW300, and also did the direct wiring mod - and absolutely no change whatsoever.

Mods include a HKS GT-RS turbo, Greddy front mount, Apexi pod filter, some kind of FPR, Fujitsubo titanium exhaust and standard ECU (no tune).

I have taken the car to a mechanic and he checked all electronics, said that they were fine.

The fuel pressure was very very high though... I'm assuming the fuel pressure reg has been adjusted as there is no electronic tune??

Any suggestions?

Cheers.

Sam

[Ben C34]

Hmmm. High fuel pressure sounds wrong.

How high? How did mechanic check all electronics? That's really hard to do! Or did he just check fault codes and the were none.

Clean your aac valve.

Get a nistune and get it tuned properly.

[V28VX37]

...

I replaced the fuel pump from the standard unit to a Deatchworks DW300, and also did the direct wiring mod - and absolutely no change whatsoever.

Mods include a HKS GT-RS turbo, Greddy front mount, Apexi pod filter, some kind of FPR, Fujitsubo titanium exhaust and standard ECU (no tune).

...

That's a long list of mods to run untuned. What superben said, get a Nistune and have someone reputable tune it all properly.

Besides the AAC valve you could also check that your CAS is ok (can cause random issue like breaking down at higher revs if busted) and maybe even the O2 sensor.

[samtaylor]

Hmmm. High fuel pressure sounds wrong.

How high? How did mechanic check all electronics? That's really hard to do! Or did he just check fault codes and the were none.

Clean your aac valve.

Get a nistune and get it tuned properly.

Yeah the high pressure fuel I cant explain. But I have a feeling the owner before me had it boosted to accomodate for the mods.

I am yet to get a scan tool onto it, but thats my next step.

Saving for a Nistune as we speak. I am weighing up seeing DVS or Powertune - both reputable r34 tuners.

AAC valve? Ill have to suss that out. Thanks for the tip!

[samtaylor]

That's a long list of mods to run untuned. What superben said, get a Nistune and have someone reputable tune it all properly.

Besides the AAC valve you could also check that your CAS is ok (can cause random issue like breaking down at higher revs if busted) and maybe even the O2 sensor.

YES it is sort of stalling at higher revs when I boost it over about 5000 rpm, sort of like fuel cut.

Im hoping it is something simple as I am loving driving the skyline, coming from a boosted STI, it is sooooo much smoother.

Thanks guys, much help!

[Ben C34]

It is hitting the load limit on the stock ecu. raising the fuel pressure won't fix it and is heaps ghetto .

I wouldn't be giving it a hard time unless you want to kill it.

You can get the codes by just jumping the terminals in a plug. Google how to see codes r34 or something like that.

[Kinkstaah]

Drive off boost until you get a tunable ecu (of any kind)

Pretty much rule 1 of any mod regarding the engine

[samtaylor]

Ok cheers heaps, I havent been giving it a hard time as I know all about blowing un tuned engines. I am getting it scanned and looked at this arvo, so hopefully we can get a Nistune chip in it ASAP and get it running right with a bit more power!