o/t Rangerover starting probs
Turbo Mini Forums

we have a prob with one of the workhorses, its a classic rr with 3.9 v8, the engine spins over, but no bark?

its been hunting at idle and wanting to stall recently when first started, and often stalled when first put into gear, but blipping the throttle seems to sort it

its got good sparks, plugs get wet after its spun over for a while, so fuel is getting in there

after a squizz on google, i believe there are a few likely suspects, idle air control valve, maf sensor, and coolant temp sender
(due to the dodgy idling when cold, the idle control valve or coolant sensor seems most likely)

what i cant find out is how to test them though....

is there any way to test the maf meter? ive given it a good going over with carb cleaner, but no change...

another thing, should the idle air control valve be open or shut on a cold start?
it seems that the valve is always open, alowing air to flow into the plenum, ive taken it off, cleaned it up, and gentle pulled it out so that the valve seats, but as soon as the ignition is turned on, it zips straight open, and then stays that way? which doesnt sound good

to rule this out though, i clamped the hose, but still, just spins over not firing?

the coolant sensor is easy enough, test its resistance against temp, at 10c (or 50f), its reading 973ohms, but will test it through its temp range tomorrow

this badboy is needed at the weekend, so need to sort asap, anyone got any pointers?

p.s. easy start wont work either :(

cheers in advance

joe

"Turbo's make torque, and torque makes fun"

"did you know you can toast potato waffles?"

I hate these fuckers, my dad had 2 or 3, broke down on me too many times so I went and bought my own tow car!

Have you checked for compression?

was the 3.9 OBD1?

I don't think so Dave, in fact I don't think it even has an engine management light on the dash.

I had a 3.9 carb. It was piece of shit. If I remember correctly, there's some cables under a panel by the passenger seat in the door step that you do diag's with.

I've got a haines book of lies if you get stuck.

LR4x4.com

cheers guys, andy, might have to take you up on it if i get stuck tomorrow!

tar dave, no dont think it has a diagnostic port? cheers for the link, will ahve a skeet now

"Turbo's make torque, and torque makes fun"

"did you know you can toast potato waffles?"

I haven't got the exact figures for Leyland/Rover ones but 973ohms at 10C sounds wrong.
They are usually NTC sensors (negative temperature co-efficient) so have a very high resistance at low temperatures and low resistance at high temperatures. The values on the WeberMarreli ones I'm using are 6,000ohms at 10C and 380hms at 80C.

If the Rover ones have a similar range, you won't be getting cold start enrichment.

Also, the normal operation of an IACV is to drive fully closed first to find it's own zero (as they have no internal reference) then to wind out a given number of steps determined by temperature etc. Otherwise the ECU would have to "remember" where the valve was exactly when the engine was last stopped.

But Rover allways did things differently......

Schrödinger's cat - so which one am I ???

Jo has it got compression?

yeah tom, compression is ok, about 115 on all pots (dry)

i presume the not starting with easy start would suggest that, at this point i have no idea why it wont go with that stuff, another piece of the puzzle

rod, your correct as usual, the resistance goes down with temp, looking at the resistance vs temp table i found online, at 10c its telling got the resistance is should have at 70c, so i thought i had found the problem, but replacing it hasnt cured the problem and the iacv is still wide open, even when unplugged (should the spring force it back out?

got one on order off ebay, but as a temp measure, blocked the pipe again, and still the barstard wont go?

so the only thing i havent been able to test/replace is the maf, and seen as they cost a fair whack to replace, is there anyway of telling if its duff?

tried on the landy/rr forums, but they dont seem as technically minded over there,

thanks for the imput so far

joe

"Turbo's make torque, and torque makes fun"

"did you know you can toast potato waffles?"