Freelander 1 surging at 1500

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Greg Storm

Member
Posts
50
Location
West Sussex
Hi all, been following for many years and probably done everything listed but need some advice please. just so you know it's an 04 td4 with 117 on clock 30 are since I have owned it. mods are egr bypass, synergie 2, new injectors, bow breather, new vent hose, all fuel air and fuel filters, sportex intercooler hoses, de-cored cat, new Bosch "fuel pro" copy maf using higher settings on synergie, overhauled hp pump. all connection cleaned and checked as per typical checks.
So here's the problem - car always starts and once fully warm runs without noticeable fault, but if you stop the car and let it cool so temperature is not cold or up to temp and restart and feather the throttle to 1500 the engine picks up to 1800 and then labours and drops to 1100 and lots of diesel smoke as the revs go up and down, revs above 2000 seem OK and turbo sounds normal. Tried both Mafs and disconnecting synergie and no maf but behaves the same so don't think it's that, pulled each injector lead and all had same effect and throttle response but obviously can't discount them but not sure why if there leaking they would be at a specific temperature. So obviously it's got a lot of diesel knock and smoke and vibration and the surging throttle is a lot like an SU carb with an air leak. gonna fit new fuel filter as it overdue in age but other than that not sure what to try next -solenoid valve ?
 
Has the fuel rail sensor or it's harness got corrosion on the contacts? Most will have the overly harness and replacement sensor by now. But some might have survived this long. That's where I would be checking first.
 
Hi Nodgy all connection are clean no corrosion or pitting, can add it to my list but be good to find someone who has had the same symptoms
 
Crank and cam for start and sync. Cam is only for starting and that's fine, crank can sometimes be rev related but not often temperature. I think it's fuel or boost due to the fluctuation
 
Hi Nodgy all connection are clean no corrosion or pitting, can add it to my list but be good to find someone who has had the same symptoms

It's best to look at the live data while the fault is doing it's thing.
Sounds like a fuel rail sensor fault to me though.
 
yep it's certainly could be fuel pressure so fitting a new filter tomorrow and examining lead etc. unfortunately not any good specialist close by other than main dealers which is not in budget at the moment
 
Hi Nodge, just remembered I have a turbo gauge scan tool in the cupboard so I think that can read all the basic parameters, do you know what fuel pressure - map - maf - temperature etc should be
 
The low pressure fuel supply should be over 350 Kpa at idle, but over 380 is better.
The high pressure rail should be over 25,000Kpa at idle. Increasing to around 100,000Kpa as the engine gets to the redline.

Make sure the Synergy is turned off, as it affects the figures.

Hold the revs at the speed where the surging appears and watch to see what the rail pressure is doing;)
 
Ok after fighting to get the new filter replaced would you credit it but this scan tool shows frp in the handbook but will not display it on screen so that's blown that idea, is there a cheap scan tool that definitely display fuel pressure ?

on a seperate note does the synergie pull voltage from the 5v fuel pressure switch supply to recalibrate the maf ? and if you unplug the pressure switch does the system default to a set pressure.
 
Ok after fighting to get the new filter replaced would you credit it but this scan tool shows frp in the handbook but will not display it on screen so that's blown that idea, is there a cheap scan tool that definitely display fuel pressure ?

on a seperate note does the synergie pull voltage from the 5v fuel pressure switch supply to recalibrate the maf ? and if you unplug the pressure switch does the system default to a set pressure.



Of it's after 2005, then a basic elm327 Bluetooth dongle into the port will work. I use Torque on my droid for logging such information.

Unplugging the Synergy at the fuel rail sensor will take it out of the system completely.
All the Synergy does is fool the EDC that less fuel is flowing than is actually the case. This way the EDC add more fuel and boosts power accordingly.
 
If it's a facelift, then it should be OBD2 compliant.

Use the standard plugs so the Synergy is out the system. You can't diagnose faults with additional fudging boxes in the system.
 
reason for asking is if I unplug the synergie I don't get a maf reading and as its not a genuine maf it all gets a bit breathless. If the problem is in the synergie box or wiring replacing standard cable might not improve things. will order a dongle and see if that can pull the data thanks
 
so got elm327 but everything bar fuel pressure has a reading, I could only borrow an android as everything in the house is iOS. Used torque app as suggested via wi-fi but not dice. Anyone any ideas how to get this working ?
 
Torque shows fuel rail pressure on my TD4.
I know nothing about Ios, other than it only does what Apple want it to do.

I'm sure there must be Ios must have some other engine testing apps available on Ios.
 
Been looking on the net for info on the Turbo solenoid valve but don't seem to be able to find some simple information so could do with some assistance please.
The three connectors go manifold vacuum at the top - turbo in the middle and vent on the bottom. so the question is on tick over is there vacuum at middle bottom or both ?
Have been doing a lot of testing using basic tools and hope to post some info once I have tested the results.
 
so did a leak back and then popped along to an indiependand garage who confirmed the leak back was excessive and no codes stored. Of to PF Jones for 4 recon injectors and surprisingly I found a place on eBay in Poland selling M47 manifold gaskets set for £18 delivered, Everthing in and connected so starts and restarts should reveal all. Thank god for the good weather as been able to ride the bike to work
 
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