Help needed with 3.5v8 efi!!

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Landyandy23

Landyandy23

Member
Posts
21
Hello everyone,
I have been having a lot of trouble with my v8 defender, struggling to get it to run right!! I have done a top end rebuild replacing camshaft as worn with a Kent can h180. All I've been able to find is timing the engine to 8 degrees btdc, however it does not like this it tries to stall runs at about 400-200 revs then stall after initial start up. But after few miles it will drive plush but loss of power at times and when higher up in the Rev range in third and fourth then with pretty much each gear change a back fire will happen and a foot flame out exhaust any ideas??? Cheers Andy
 
Had similar when I put the distributor in 180 out. Wouldn't fire at all, put distributor back in, ran like a bag of nails - wouldnt idle, wouldnt rev properly - so kept advancing it until it idled smoothly and didn't pink under load.
 
Nonononoonoononoooo. I had to do that because I was a dunce and didn't fit the distributor properly!

If the timing is out the you need to sort that. To advanced/retard the timing you just need to slacken the nut that clamps the distributor down off, then turn the distributor clockwise/anticlockwise until you get it right.

Try this:
Its also worth noting that the best ignition timing in any given engine, is to achieve the most advance it can tolerate without pinking. ( Audible pre-ignition).
This is achieved by setting your V8 timing to about 4 deg. BTDC (assuming you've been through the distributor check list completely).
Then tighten the distributor so that you can (with effort) still turn it by hand. ideally put a tip-ex mark or small scratch on the distributor body and engine block to record this spot.
Next road test the car and simulate high load by quickly shifting into a high gear or if Auto allow to change quickly up to 3rd or 4th Ideally you need to find a small hill or incline, now if you apply full throttle the engine should respond without pinking, find a safe place to pull over, open the bonnet and turn the distributor through a couple of degrees only, anticlockwise, this will add slightly more advance timing and if you do the same test, and repeat it until pinking is noticed you will be very close to your absolute best timing criteria
So now all you need to do is turn the distributor clockwise by the same amount by an amount to counteract the last adjust, retest for the absence of pinking and that the job done, you will have just achieved the best maximum timing position for your car
Click to expand...
 
as above!

top tip..as they say on that ****e programe..go maplins buy piezo buzzer (£2), rip out [pizeo plate solder screened audio cable to it with 3.5mm jack plug on other end.stick piezo to block with glue.,
(OR buy from ebay bosch bmw knock sensor £5 and bolt to block.)
then plug 3.5mm jack into your car stero as hear pinking long long time before you will by ear..

ok this relies upon you having aux in on car radio, but most do now..

pinking heard this way sounds like an explosion!!you can not miss it!
 
Yes would cause sputter, but could be something else like air leak. Try advancing anti clockwise to 10 or 12. It will raise idle too. If you see improvement, you're on the right track.
 
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Cheers guys I shall try that tonight, how do you know when you've gone too far with the advancing is it when the idle stops getting higher?
 
When it pinks high gear low revs full throttle. Alternatively If you take no.1 plug out and rotate engine by hand, probe down pot to confirm where tdc actually is on pulley and tippex it. Should be running right at 5 to 8 btdc assuming dizzy is advancing properly and pulley tdc marked correctly
 
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Could have been correct timing before hand but using crank pulley markings to set timing could have set wrong timing if the marks on the pulley are out.
 
Just an update I've had some luck advancing the timing more than 8dbtc to about 12ish and changed the airflow meter for another one and has improved but start up from cold is still dodgy
 
The improvement came from airflow meter as had other on left timing the same, I put original back on car as idle was all over the place in the end I found an air leak which cured the idle :) that was months ago I had the idle issue but now thinking of swapping to hot wire??
 
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