Setting up the static timing & idle on a 3.9?

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Kai Robinson

New Member
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4
Hi guys, hoping some of you could give me a hand with this! I'm working on a Range Rover Classic for a guy who lives down the road from me, and the thing is honestly getting on my nerves, trying to get it to run.

Now, he had troubles getting it to start & run properly last year (before he rang me), and determined that the problem was the ignition amplifier module on the side of the engine, and the points setup under the distributor (Lucas 38DLM). He replaced both of those, and still couldn't get it to run, so he replaced the coil as well. Still nothing. So, he gave up on it, until he found out about me from another friend of mine, and i got called up...nearly a year after it stopped working.

Anyway, turns out that he hadn't peeled off the backing for the amplifier module (thus ensuring it had no ground!). Now, that was easily rectified, but unfortunately, both times, the distributor has had to come out of the engine. I'm pretty sure that prior to my arrival on scene, the engine had been turned over without the distributor in.

So, i offered to set it up from scratch. Now, there's been conflicting information on exactly HOW to set it up.

#1 Piston was set to TDC (screwdriver down the plug 'ole), and low and behold, the TDC mark on the pulley correspond with it. Now, i must mention, the Pulley goes like so:

AFTER 12__|__|__|__TDC__|__|__|__12 BEFORE

Each mark i'm guessing represents 3 degree's?

So anyway, normally, i'm used to setting an engine to TDC making sure the distributor is pointing to #1 cylinder on the distributor. However, i was told several DIFFERENT things. First was 'set it to 8' BTDC'...so i tried just shy of 9' on the pulley....no dice. Then i was told 6' BTDC. Worked, but ran like a bag of hammers and wouldn't idle. Then i was told 'set it to TDC mate!'...which i have done.

Now, it starts if you give it a little throttle, and it runs all the way to the end of the rev range, it's firing on all 8 cylinders...but it just refuses to idle at all and i'm unsure of if its related to the static timing, or something like the Idle speed control valve on the rear of the plenum has packed up.

I recorded a video so you can see exactly what it's doing, and if the engine is well and truly shafted, or if its something simple that i've overlooked!

[nomedia="http://www.youtube.com/watch?v=dAIQKptf_mY"]Range Rover V8 - Idle Problems - YouTube[/nomedia]
 
6 degrees btdc ,if steppermotors is stuck open it will rev even though you got it right with tdc on 1 you should watch rockers so that you no no1 is on compression stroke, it may take a while for hydraulic tappets etc to open valves fully ,sometimes 20 mins or so ,you cant expect it to run fine straight away after been stood for so long
 
Right - i'll set to 6' BTDC. From where i am, i presume that i'm already on the compression stroke, but i need to advance the static by another 6 degree's?

As for the stepper motor/iac valve - if it's jammed open, i'm guessing it's letting too MUCH air in, and causing the lean condition/no idle?
 
the easy way i find to check that youre on tdc compression is to pop the rocker cover off on the passenger side and check that the front two valves (no1) are not open, when approaching tdc on the crank. if one valve is open then you know its exhaust stroke, so you need to rotate 180 degrees and check again.

must admit i find mine runs sweetest at 6 degrees but its a 3.5 which is supposed to be 0 degrees. i suspect i have so much chain slack that i have advanced it that amount to where it makes good power and idles cleanly.

the other option is to tickle the dizzy around to see if you can find a spot where it will either catch and start, or at least idle once running.

if stepper motor is stuck open i would expect typical RV8 fast idle, as there is usually plenty of fuel being injected to allow the engione to run whatever the stepper motor is doing...
 
try it with the air filter off mate, that filter looks well blocked to me mate the way its collapsing the inlet hose when you open the throttle.

as a pointer, that main inlet hose is also VERY common for cracking, you would probaby hear the leak but its well worth checking.

could it simply not get enough air flow not to idle due to that filter? looks to be having a hard time to me!
 
Not a fast idle - it's just NO idle. The thing only runs when you give it throttle. Took the filter off completely as well, still no dice. Sorry if the video was boring! :(
 
no only covering up for my own laxness,was stepper motor working it is supposed to open for idle when butterfly is shut when you turn ignition on you should hear it winding
 
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