Idling- not my van's strong point-ideas?

[matt71]

Hi folks,
my EK van (stock 138 engine, carb, exhaust) is running really well out on the highway - power when you need it, no flat spots when accelerating, no screaming revs (loving the 3.55 diff- the only mod to date -I can hear the radio now!) but at the lights...... it's very rough- very shaky, a very uneven idle, especially after a long highway burst. It threatens to stall at times but with a tap of the accelerator it corrects things in time to pull away.

- what is the consensus on what component I should look at first- carburettor?

BTW on cold start up the choke has to be all the way out but doesn't really have a huge effect on the revs pulling it in and out- is the idle set too low in general?


Any clues would be greatly appreciated.

Cheers
matt

[fingers]

Hey Matt......where ya from mate, if its performing well at all other speeds then adjust your idle speed and mixture ......check this link out to Harv,s stromberg guide....Section 8 ,,Page 52..........
try adjusting the idle as per this guide , how long since she had a good tuneup, plugs, points, leads,etc .....Fingers

[choppedfan]

Matt,

Sounds like a vacumn leak, spray WD40 around the base of the carby and work your way up, if the revs rise you've got a vacumn leak

Mick

[matt71]

Thanks fellas- will give both a go this arvo.


Fingers I'm in Dromana- it's not been long since a spruce up (plugs/points/etc) so I reckon some attention to the carby might be the way to go.




cheers
m

[artyfartymarty]

if not a vaxum leak i would suggest its the points/distributor, those things were always going out of allignemt on my olod dizzy, which was well worn too (excessive play)
replace the whole thing with electronic dizzy from a blue/black motor, it'l cost you a couple hundred max. you'll never look back on those crappy point again, your car will start, idle, run better, be more efficient and stay in tune for longer than one week., it doesn't look too out of place either if youre trying to keep as stock looking as possible.

[MeFB]

replace the whole thing with electronic dizzy from a blue/black motor,

Will they fit on a grey? Done it to red motor before, but didn't know think they would fit a grey.

[choppedfan]

replace the whole thing with electronic dizzy from a blue/black motor,

Will they fit on a grey? Done it to red motor before, but didn't know think they would fit a grey.

Go the Pertronix conversion to the grey dissy if this ends up being your problem I've gone this way after reading the others on here that had success with the conversion

There is a link here somewhere

Mick

[Trev]

When I had my grey I found that if I over adjusted my rockers to eliminate the tapping noise it ran fine and became rough at the lights of conked out all-together, so I would give them a little more space and all was fine.
Sounds a bit like what you have described.

[artyfartymarty]

replace the whole thing with electronic dizzy from a blue/black motor,

Will they fit on a grey? Done it to red motor before, but didn't know think they would fit a grey.

Go the Pertronix conversion to the grey dissy if this ends up being your problem I've gone this way after reading the others on here that had success with the conversion

There is a link here somewhere

Mick

damn, forgot we're dealing with a grey. thats the root of your problem right there!
forget the dizzy conversion, just go for a red with HR and disks conversion.... it'll idle, have power to pull the skin off hot custard (unlike a grey) have parts galore to choose from and be able to stop, and you'll loose that crappy king pin hollywood steering. 20 birds killed with one stone.

[artyfartymarty]

"it's very rough- very shaky, a very uneven idle, especially after a long highway burst. It threatens to stall at times but with a tap of the accelerator it corrects things "

sounds like a very lumpy cam...some people pay lots of money to have their car run this way, myself included

[matt71]

thanks gents for all your input.

The faster idle adjustment has helped-it's about 60-70% smoother at idle , there didn't seem to be any manifold leak based on the wd 40 test and Trev your suggestion is my next port of call.

cheers
m

[artyfartymarty]

Matt, what's your timing set to?

[Bluehaze]

My grey used to idle like it had a hot cam, turned out one of the spark plugs were sparking to ground on the outside. I could hear the arcing on a plug, and under low light could see the blue arc at the edge of the plug boot. Only at idle.

[fingers]

thanks gents for all your input.

The faster idle adjustment has helped-it's about 60-70% smoother at idle , there didn't seem to be any manifold leak based on the wd 40 test and Trev your suggestion is my next port of call.

cheers
m

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Hey Matt did you adjust the fuel mixture as well as the idle speed ..........Fingers

[MeFB]

Some people make the mistake of using the idle mixture to adjust the idle speed, lean = faster idle, rich = slower idle, but this isn't the way to do it as you'll have poor pick-up and idle. The screw on the carby's throttle lever should be used to adjust idle speed. The mixture is a separate adjustment. The idle mixture and the idle speed need to be adjusted together as idle mixture affects idle speed.

My guess, and it is just a guess, is that the reason your choke isn't making much difference to your idle speed is because your idle mixture is too rich to start with.

Here's an extract from Harv's most excellent guide (hope you don't mind Harv):

To set the idle speed and mixture:

1. Warm the car up to normal operating condition. Check the choke is off. Leave the air cleaner in place.
2. On automatics, the transmission should be in DRIVE (D) with the handbrake firmly engaged.
3. Fit the vacuum gauge to the inlet manifold and the tachometer (where available).
4. Adjust the slow idle adjusting screw (54) until the engine idles at 480-520 rpm (check with a tachometer, timing light counting or “by ear”).
5. If you have a vacuum gauge, adjust the idle needle valve (59) until you get the highest vacuum
possible (this should be between 17”-21” Hg, or 60-70 kPa, or 8-10 psi). This can be difficult if the vehicle has a large cam (high valve overlap) as the vacuum at idle will fluctuate. In this case, adjust the idle needle valve (59) until the tachometer reads maximum rpm. If you don‟t have a vacuum
gauge or tachometer, turn the idle needle valve (59) slowly inwards until the engine starts to run
irregularly. Back the idle needle valve (59) outwards until the engine begins to “roll”, then inwards
again until the engine runs smooth.
6. Check the engine speed again, and repeat steps 3. and 4. above until a satisfactory idle is achieved.
7. Remove the tachometer and vacuum gauge and refit any vacuum lines that were disconnected.If a rough idle persists after the mixture screws have been adjusted, check for vacuum leaks. These could result from unplugged vacuum fittings, carburettor flange gaskets that were torn during installation,cracked lines or loose bolt/screws. A quick way to check vacuum leaks is to spray WD40 in the suspected area with the engine running – if the engine speed increases, there is a vacuum leak.