Limp mode 2001 ZD30 automatic

[pacman]

Hi guys my name is Matt I live in the hunter valley NSW my nick name is pacman. My hobbies include boating / water skiing with my young family & caravaning.
I am new to forum sites & need advice & support for a 2001 GU ZD30.
I bought the car with a failed engine.
Bored honed / crank polished / new cylinder head / intercooler & turbo.
Dawes valve & electric lift pump installed.
Engine drops into limp mode on acceleration or easy driving, boost has been adjusted from 10psi up 18psi limp mode can be over riden with a release on throttle & a reapply but drops into limp mode again.
I have read lots of post explaining similar faults but with no final result / resolution.
Limp mode does not present any codes.
Any ideas????

[Sir Roofy]

welcome aboard mate back your boost of to 14 then disconnect the battery for an hour or so to reset the ecu
see if this will help

[threedogs]

also as I said on the other thread is buy a needle valve to control spool up rate .
As it is now it must be hitting 18 just off idle

[pacman]

Threedogs spool up rate it would change the MAF readings ??
The needle valve does it bleed off vacum the actuator to control spool rate??
What side of the intercooler should the pick up point be for the Dawes / boost gauge only reason I ask is that the boost sensor is after the core my pick up point is before the core.

[threedogs]

boost sensor is at the front of The IC, If your IC is oily forget it until you get a Tigged one
The needle valve will controll how fast you get to 18psi
Have a Google of anything written on the ZD30 by Chaz Yellowfoot he and Rumjas are gurus on these motors
Have a read you'll understand it a bit more , , have you looped off the Air solenoid and return air hoses[3 hoses] in the air cleaner box.

[pacman]

Fully sealed tigged IC already installed
The hoses on the air cleaner box air not looped blanked off with stoppers should theses be looped not blocked??
Will do some more reading thanks threedogs

[BillsGU]

Your Dawes valve is just set too high. Screw it out to reduce your boost. It may take a few runs up and down the freeway with a stop every now and then to adjust the boost setting. You want it to be just below the limp home pressure. It does vary from car to car a bit - but is normally around the 16 PSI mark.

[threedogs]

while doing all this give the MAF a spray as well

[Remdogg]

Mudski will have the needle valve and the instruction on what to block. They were easy to follow.

[threedogs]

I agree with most here as we all went through it.
Grab two spanners to suit the dawes and the allen key for the Dawes and go for a drive,
First get your boost to 15psi or there abouts, mark the dawes,
Close the needle valve,, then idling ,, slowly open the needle valve till actuator arm falls away off the turbo
lock off the needle valve this is only ball park, go for a drive and see how it goes,
forgot to mention if you have a manual or auto

[SG1]

Hi, had this struggle for a long time to, it came down to backing dawes valve of until I was at 14 psi, have an auto as well, really bugged me for awhile as others where getting higher boost but then realised that mine was going really good at 14 psi with okay EGT's and good fuel economy, I have a feeling that my VNT grub screw needs to be turned down a bit but that's another story, as others have said back the Dawes valve of until you don't get limp, check your MAF and or clean replace if you have a spare or can borrow some one elses.

[pacman]

Hi guys been busy with the truck, hooked up my 2T boat today found a nice constant incline & adjusted the vacum actuator arm so limp mode would not cut the fuel & adjusted Dawes valve up until limp mode would cut the fuel I could only get 12psi also fitted EGT gauge. MAF sensor is new & clean ( done it on the weekend ) replaced boost sensor with a known good operational one.
The incline is around 6-8 degres & 1klm long.
Boost 12psi
EGT max 625
Engine 3250rpm
Auto transmission with OD off
Needle valve is ordered. As suggested from the threedogs & remdogg
Can the MAF sensor voltage be adjusted to trick the ECM to prevent fuel cut??
Thanks heaps guys I am getting there

[Remdogg]

So does yours hit limp mode after 12? Have you checked the error code. A bit more boost would lower you egts from my experience.

[threedogs]

sounds like your neally there I'd be backing off when temps approach 550 c
leave it till you have the needle valve you may be surprised

[BillsGU]

I would not worry too much about the exact boost pressure as some of the gauges are not very accurate. What brand of gauge do you have? I set my gauge to alarm at 600 and back off (change the auto down a gear) to keep the temp below 600.

Set the dawes valve just below limp home and you will be OK. Good power and good fuel economy (well - relatively any way).

[pacman]

Ok remdogg no error codes
Billsgu VDO gauges (analog) I like old style. She is a little thirsty on fuel.
Sit tight off water skiing for the weekend will get back into it next week
Thanks guys

[Remdogg]

Ok remdogg no error codes
Billsgu VDO gauges (analog) I like old style. She is a little thirsty on fuel.
Sit tight off water skiing for the weekend will get back into it next week
Thanks guys

Mines a CRD but I had an over boost error code even though the engine light didn't come on. No sure if Di patrols log it.