95 lpt almost cutting out, kangerooing MY99

[Aintree 900]

So symptoms being a massive hesitation especially under load or slight incline, i initially suspected DI pack and was rather hoping to be the case as have a spare permanently in boot, below is a list of all i have gone through but would welcome ANYTHING you can perhaps think i may have missed....however stupid it may seem....

Still not got to the bottom of this, after taking throttle body apart most of the wiring had lost it's insulation inside of plastic cover was peppered with bits of various bit's of dried up colored insulation, had a pal with Tech 2 pull codes ...thanks DEE VEE and we got back throttle position sensor fault, as a stop gap i did try to "re insulate" wires with electrical tape which was a real fiddle and faff but in the absence of a spare TB needed to get it running.

Now i was chuffed, because it ran just fine ....for a day  then reverted to almost cutting out even at slow speeds, you could just about dip clutch to drive around it but horrible to drive especially on a gradient....
Ordered a known good TB from Jamsarb, thanks Martin, and assuming my troubles were over fitted that one....and got exactly the same symptoms, end of tether now as this been off road for over 3 weeks and beloved getting buses every day and i am getting serious grief !! god how expensive are buses nowadays...

So in order of what i have done as follows and i have done all at least 2 or 3 times now...

1 cleaned MAF with isopropanol
2 Dissconected Maf
2 Took off whole of pcv system 6 inc oil seperator box and cleaned and leak tested.
4 Checked and replaced all i think .. breather tubes
5 done the bolt mod on boost valve pipe in a vain attempt
6 tried 3 seperate DI packs
7 New correctly gapped plugs, yes BCP 7 whatsits like it's always ran on.
8 Removed cam cover and checked cam breather tube.
9 Fitted new fuel filter yesterday.
10 Removed and checked all the earthing points i could see, except bulkhead one i couldn't find ....where are you ?
11 Replaced 2 one way check valves in small pcv sections.
12 Cleaned and also ran without airfilter.

Had Tech 2 on it again yesterday and now not showing any fault codes which is more confusing, cant understand how it ran perfect after doing my botch up job on TB wiring for a good few miles and now problem is permanent, engine idles perfect from cold or hot, i would have thought an air leak that i may have missed would give a dodgy idle speed, revs cleanly and starts perfect....

Contemplating swapping out fuel pump from 9000 as a last resort but not feeling the love for much more car diy at moment...

So any help chaps before i phone Steptoe and Son, thanks, Ian.

[sgould]

Welcome!

When you say that you have replaced the "breather pipes", do you mean the small diameter rubber pipes that run from the dump valve at the front, around the side of the engine to the three way valve on the bulkhead?  These are the vacuum pipes and there are four of them.  Three longer ones and a short one that runs from the plastic fitting on the inlet manifold to the fuel relief valve.



The three  pipes at the bulkhead valve A, B & C

A loops round to E
B goes to the control valve on the front of the inlet pipe
C goes to D and onto the throttle body
F is the short pipe to the fuel rail, and is often missed.


You could also check the resistance of the crankshaft position sensor.  Do this at the blue connector under the big inlet pipe, behind the top of the engine. Disconnect it.  Three pins.  You should only find a resistance across two of the pins.  That should be between 770 ohms and 950 ohms.

I would also be checking the fuel filter and fuel pressure.

Reinsulating the throttle body wires with insulation tape might not have fixed anything.  It's very hot in there.  If I was doing that job, I would be unsoldering one end of each wire and fitting heat-shrink tubing and a heat resistant sleeve.

But also go around and wiggle lots of wires.

Has the thermostat been changed recently?  If so, was the earth wire that fixes to the thermostat housing bolt, put back correctly?

[Aintree 900]

Hello sgould, and thank you for the welcome,
 I registered on here ages ago but if i am honest kind of forgot about it well today rediscovered it and it certainly has evolved into a rather nice compact , informative and friendly place to be, so well done all involved firstly...

Yes breather pipes, the ones i have checked  and have replaced are the ones on throttle body itself,and i replaced the long one to the cobra pipe, certainly not F and E on your photo so that is tommorow's job, have replaced fuel filter but do not have access to pressure guage to test fuel pressure, have cracked banjo on rail and there is fuel getting there, but as stated car idles and revs cleanly at a standstill, no T,stat changed for a year or so.

Other thing i forgot to mention whilst running at 4k rpm doing warm up and air test on Tech 2 there was a strong fuel smell from outside car as if running quite rich if thats any help.

 Thanks, Ian.

[Aintree 900]

O.K have just braved the elements, it's lashing down ! to take a look at where you photo relates to and i cant seem to find it with my rubbish torch, i think daylight is required.

[Audax]

Have you had someone check the firmware version installed on the engine ECU? There was a few updates some of which were related to throttle body calibration. The release notes say:

"More robust and increased diagnosis of fault related to the throttle housing. More robust knock detection signal, decrease the risk for engine power loss. More robust function of ignition retard. Possibility to adjust the engine idle rpm with help of Tech 2."

I'd also suggest that if you have access to Tech-II to check the status of all the atmospheric sensors with the engine off but ignition on to make sure they are reading right. A live data capture with Tech-II may also reveal what the car thinks it is doing.

[Aintree 900]

Hi Audax, can firmware upgrade be done via Tech 2 ? and by live data i presume you mean driving car whilst Tech 2 plugged in.

 Ian.

[Audax]

Yes, you do the upgrade with Tech-II but you need access to TIS or GDS and security access.

Also, live data is something you get with Tech-II while driving, you use it to draw graphs and do point in time data recording to analyse what the car is doing.

[Aintree 900]

Thanks for that, my pal with Tech 2 is a lot more i.t literate than myself i shall relay that info and see what he says, Thanks.

[Aintree 900]

Replaced hose  f and e, and sadly no change, think i will have  to have another session with diagnostics....

[Aintree 900]

Just a quick update on this, so today after many many googles decided to swap out my crankshaft position sensor , CPS only because i had a spare one i never got around to fitting, and i read 1 post in the whole internet....some bloke in Mexico, see how desperate i am now.... which stated they suffered hesitation rather than just poor starting with a dodgy CPS,  so after some cursing trying to remove old one managed to drop my extension bar down the engine somewhere, you know when you hear it drop and land on something  but didn't actually see where it went.. so after a while spotted it through small lower vents under radiator.....that's what got me in the general direction of the intercooler....... which upon further investigation is shaped rather like a bannana , it bends in from the center with a geometry not dissimilar to said fruit.

 So obviously this is wrong but anyone care to tell me this could cause my symptoms , and how they get like this, took main pipe off from intercooler to cobra and was very oily, which i know a certain amount is o.k from pcv but this was properly wet... wish i had taken picture, i shall tommorow.

Is there a way to check for intercooler leaks without removing, thanks again.

[Audax]

Well, if the intercooler is split then this may well be the cause of the problems (and also why I said if you have a tech-II to check the status of all the atmospheric/pressure sensors). What you can do is block one side of the intercooler and pressurize it to see if it is leaking or not. Oil is possibly PCV or possibly turbo, I'd suggest you remove the intercooler and check it and see if it's full of oil or not as if it is then it may be a turbo spinning oil out of the seals.

[Aintree 900]

Hello Audax, not had the chance to re Tech 2 it yet but weather permitting will remove I/C tommorow and work out how much more this car is going to cost !! oh boy.
 Thanks, Ian.