Red motor problem

[Dave_EH]

Hi,

After fitting a new top end, carb etc on my 179 red motor it has been going trouble free for about 350miles.

Last week I took it for a drive and it seemed a little off colour - just not making quite as good power up high, and stalling occasionally at idle.

I thought the old distributor must be the cause and installed an electronic commodore dizzy on the weekend and it ran a little smoother - but I still thought it wasn't quite right.

My girlfriend's Dad has been driving the car to work the last few days as his car is in for repairs.  This morning he broke down and said it seemed like spark.  It didnt start well and started to miss then wouldn't start.

The motor is assembled as follows:

Fresh bottom end with mild cam
YT head - just reconditioned
Electronic dizzy
Holley 350 - rebuilt about 5 years ago
X2 headers

I took the old points distributor to the car this arvo and installed new points - I had assumed the second had electronic unit had crapped out.

I managed to get it running - but really rough and on 5 cylinders.  

It was sending a fair bit of smoke out the exhaust also (unburnt fuel I assume)

At the moment I can't think what could be wrong.

Advancing or retarding just makes it runs worse.

I'm assuing spark at the moment cause it is the only thing that has changed.

Unless the carby has basically fallen to pieces I can't undertsand would has gone wrong so quickly.

All ideas appreciated!

Dave

[4hammers]

Dave.
No expert, but that sounds like the carb. Float sticking & sending too much fuel in. Got a fuel filter on the line??

Rob J

[fastjbav6]

Dave,
Just to add, make sure you fit the correct coil with the electronic distibutor.

Regards Seb

[Dave_EH]

Thanks Seb,

I forgot to add I changed the coil as well.  It was the original GMH/Bosch type from the commodore.

Rob,
If what you say is the case, would it cause #3 and #4 plugs to foul up and cause the timing problems?

I'll pull the plugs all out tomorrow and inspect - they have only done 350miles so it will be easy to tell if this is the problem.

No. 1 plug looked on the lean side but I didnt check the others - is it possible for say #1 and #6 to run lean even if the carb is running rich?

Regards
Dave

[4hammers]

Hi Dave.
like I said, I am no expert, but I had the same sounding problem on my old green wagon. And yes, it stuffed the plugs & made the car run like a pig. Hard to start, stalled at lights when I pulled up & blew black smoke when I started it.

BUT, with fouled plugs. That sounds as if it may be the head gasket also. Check the water in the radiator & the oil under the breather cap.

Rob J

[craiga]

Dave,

It sounds like a stuck float to me. The single carby sits in the middle of the manifold, so the intake runners are shorter for the middle cylinders (#3 and #4) so these always run richer than the outside ones. This is why you are fouling the middle plugs.

Concentrate on the carbie.

I reckon Rob J has picked it when he asked about a fuel filter, the float valve is being held open.

Cheers,

Craig.

[Dave_EH]

Thanks everyone - I will pull out the plugs, inspect and go from there.

This theory makes sense as it ran really well to begin with, then wasn't quite right.  I'm assuming that when I fitted the electronic dizzy it made a stronger spark and this overcame the the plug problem initially.

Rob - no sign of oil in the water.  Its a new gasket, and the engine hasn't overheated or anything like that so hopefully not a problem.

When I was driving the car I was giving it a good rev, so probably cleaning the plugs a little, but when Jenn's Dad was putting off to work in the city they would have been fouled easily.

Should have some good news tonight

Should I just give the needle and seat a clean out with metho or buy new ones?

Its aslo been mentioned to me that wiring in a electronic dizzy is different than the stock item.

I just ran power from ignition to +ve, green wire from dizzy to -ve and pink wire from dizzy to +ve

Somone said that the ignition wire is a resistance wire and drops voltage to about 9V - can a relay be used somehow?

Thanks for the kind help
Dave

[craiga]

Dave,

To diagnose if it is the float undo the float adjustment screw on the side of the bowl. It has a wide flat head. With this removed fuel should just trickle from the hole, if it runs out the float level is your problem.

Let us know the result.

Cheers,

Craig.

[ACE]

Hi Dave,
You can use a relay.
Regards ACE  

[Dave_EH]

I have just pulled out the plugs and 1,2,5,6 are totally fouled, while 3 and 4 are silver/oxide sort of colour (I assume lean)

Cleaned them all up and it runs terribly - just as bad as before.

The float level is just below the inspection screw - you need to shake the car to get it to dribble out.

When I squirt the throttle quite a bit of fuel comes from the venturies - and sits in the bottom of the carb - sorry I don't know all the names of the carb parts.

Mixture screws seem to be tight and in normal position.

All vacuums seem to be tight.

regards
Dave

[craiga]

Dave,

Float level is OK if the fuel just dribbles out. It could be that the jets are too big. Has the carby been set up for a mild 6? And what is the air cleaner like? Its not restricting air flow in any way is it?

The only other thing is low spark energy, so the fuel is not fully burnt. You said you fitted an electronic dizzy, did you fit the coil that goes with it as well?

Craig.

[Dave_EH]

Sequence of events:

1) Car not quite right - stalling a little at idle and not making optimum power at high RPM

2) Change to electronic dizzy and corresponding coil

3) Car going slightly better - breaks down after two days of peak hour driving

4) Replace electronic dizzy with original points dizzy and coil

4) starts but won't idle, runs very rough - plugs fouled

The carb was running on a 186 to almost identical specs for 5 years after a rebuild.  Ran trouble free, then ran trouble free for a few hundred miles on this motor - the carb sat idle for about 6 months between motors.

The car originally had poor qualiity old fuel, but the car was only started a few times before the fuel tank was replaced and new fuel in it - its gone through about two tanks of optimax fuel.

The car runs the same irrespective of air cleaner on/off

Frustrating problem at the moment but I'm sure can be fixed.

Thanks for all the help
Dave

[kma]

hi Dave.
The old dissy runs at 8 volts through a resistive wire on the coil "the one that is wound like a expansion spring and i think it is yollow." Cranking is done at 12 volts on the coil. The points would burn out  while running all the time at 12 volts.
What you need to do on the electronic dissy run a new wire from the ignition so the coil gets 12 volts while running and 12 volts while cranking. This should stop the plugs from fouling up.
Also gap the plugs to 1.5mm but if it runs like its got a lumpy cam and its hard to start, gap the plugs to 1.2mm
             Cheers from Kevin O

[Dave_EH]

Thanks Kevin,

I'm back to running the original points distributor so I'll keep with that to avoid confusion in the this post until the other problems are sorted out.

spark gap is set at 35 thou.

Cheers
Dave

[ACE]

Hi Dave,
Here's my guess.
Check the power valve in the carby.
It may have a hole in the diaphragm.
Regards ACE  

[nicko]

wow 35thou is a huge gap,try 18thou

[Dave_EH]

Nicko, without straying from topic too far: the manual says 33 GO and 38 NO GO - so somewhere in between there with a feeler guage.  

Its previously been discussed that gap can be up to 40thou with an electronic dizzy.  18thou seems very small?  Are you confusing it with points gap?

Dave

[fc4kiwi]

god almighty Im not the only one having problems with a f**** 350 holley ive got the same  as you Dave ran great then the crap came about
Ive taken the holley off and gone back to a std single barrel "holden 186"carb all my problems are gone.
As far as im concern you can stick your holleys.
IT idles cruzises and performs just if not BETTER than a 350 Holley!!!!!!!!!
Dave go back and try a std carb and see how it runs,

[nicko]

yes,i was  

[SRVLIVES]

, ,  Sorry Dave, I can't help with your problem........... but, I will be replacing the 350 on my 202 with the throttle body, injectors and computer from a VL EFI system adapted to either a 2 or 4 barrel manifold as well as installing an elec dizzy.

No cold start drama, smooth idle, better fuel economy... and all hidden under an air cleaner rather than using an ugly VK unit!