Limp mode 2001 ZD30 automatic

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.

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

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.

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

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).

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

Quote:

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Originally Posted by 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

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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.