GTA atmo not starting

Indeed ha ha ha....I bought a gta turbo from someone n this forum with similar promises.... ....
Can't quite say "all my problems are over" at least just not yet.....
(Atmo owners (thankfully) don't know what is concealed by that cover between the rear seats..and don't need to spend time scrabbling around in the back seats with crocodile clips and bits of wire).

My atmo starts on the button...(well third time at least...consistently though)....

[johnb]

I'm also interested in this thread for when I eventually fire up the A310 engine and tempt fate on the road after its 25 year hibernation.
Question for JohnC unless I've missed something obvious. For your priming switch to work, does the GTA atmo have an electric fuel pump rather than the camshaft driven pump as on the A310?

For your priming switch to work, does the GTA atmo have an electric fuel pump rather than the camshaft driven pump as on the A310?

Yes, it has an electric fuel pump John.
Just to expand on this for those that are interested. When I bought my Atmo, I was a little concerned about these electric fuel pumps as, unlike the mechancal ones, they are not repairable, whereas 20 odd years ago, you could get mechanical fuel pump repair kits. When I spoke to Renault about it I was told that the pumps themselves were very reliable but they had had the pulse sensing fuel pump relays give trouble. On looking at the circuit, I saw that I could use a redundant switch to bypass the relay in the event of a failure, which I fitted..... it is the same switch that I use for priming, so that switch now has a duel function.

[johnb]

Thanks, thought as much.
I'll just have to use the starter motor as the 'priming device'.

Picking up BIG MVS comment about starting handles. Appreciate the humour but the A110 actually has one and it's multi-functional.
It can be used to start the engine, obviously, although I've never needed to use it for that. It's also the jack handle and, after not using the car for a while, I use it to turn the engine over and prime the carburettor. It's also the wheel brace.

efi ftw

Strewth these ATMO's are temperamental, prime buttons? Does it have a handle to start as well? Get a GTA Turbo boys then all your problems will be over

your non starting,no clutch peddle,mot fail pain is just around the corner like my gta turbo that won't start. if all is ok with your car enjoy, while it lasts

[BIG_MVS]

Send it to Derbyshire then Andy. I'm sure you can come to some arrangement and scratch each others backs so to speak

got a new tdc to fit, cross fingers.

Thanks, John will check all the things mentioned this week.

Never had starting problems in 11 years of ownership until this last year!

Andy, I have sent you a PM.

[johnb]

I've had a couple of attempts at starting the A310 (Solex carb set up, 34TBIA + 35CEEI) without success at the moment.

Prior to the attempts; I set the static timing and dwell, the fuel cut-off valve is working as there is fuel at both carbs, the accelerator pumps are both working (nice squirts into intakes) and there is a spark at one of the plugs checked. Before installing the carbs I stripped them and had all the parts ultrasonically cleaned. I re-assembled them with new seals, gaskets, diaphragms, set float heights, etc. All linkages are free. I followed, as far as was possible without specialist setting equipment, the MDR procedure for checking the various settings of, mainly, the 34TBIA carb. According to the book, there aren't any adjustments possible for the twin choke 35CEEI carb and only idle screw adjustment for the 34TBIA. This screw is set at 4 turns out which is where it was before I did the strip-down. Does anyone know whether this is a reasonable starting point and is the screw turned in to increase idle speed, or vice versa?

There's another screw (pilot) on the 34TBIA at the lower butterfly. I haven't adjusted this as I believe it is factory pre-set. The only other adjustment that I can see on the 34TBIA is the screwed rod that controls the stroke of the diaphragm that feeds fuel to the injector in the throat of the carb. Presumably the effect of adjusting this could only be checked on the road, under acceleration.

At the moment whilst the starter is turning the engine over, the engine is firing but not enough to make it run. It's almost getting there but not quite. Any suggestions on settings or other diagnostics would be appreciated. Before the next attempt I'll re-check all plug and king lead fits and that there are sparks at all plugs

I know that one suggestion might be to ditch the Solex carbs and go for the Holley conversion. That's a consideration but first I want to persevere with the present set-up. I appreciate the challenge.

John ..before looking at anything too complex...suggest to ensure battery is fully charged, and in good condition (if not something you have done already)...and all associated connections/earths clean. Clearly you may have this all in hand...I only mention this as my atmo was being stubborn last week after a couple of weeks without use..even with a portable booster pack she was cranking nicely and on the verge of firing...but would not play ball. Overnight charge of battery and some threatening language did the job...
Every winter I have to charge the battery up (I think there may be other factors...alternator, battery age, ignition system component age...lack of use etc)

On these engines ..and distance/typically poor earths and the infrequent use you need a good battery...plenty of cca to get things moving in the winter months (especially when you may have other elements that might need some adjustment)...Good luck...

[johnb]

Thanks for that Dave.

The battery is new and is 63 AH capacity with a cca of 610A. It's a higher AH rating than the battery on the car when I bought it.

All the earths are good and I've meter checked the earth circuit for volt drops whilst cranking the engine and these have been negligible. The voltage across the battery when cranking yesterday was 10.6V which, according to my meter handbook, is good. I've fitted new points and capacitors to the distributor and found a new distributor cap and rotor on ebay some time ago and these are fitted. The plug and coil leads are new and are blue Magnecor, the spark plugs are new. I've checked the coils and the ballast resistors are giving 5V output and the 12V boost feed from the starter solenoid circuit works. So electrically, I'm reasonably confident about the condition of the equipment. The alternator has not been tested because the engine is yet to run in my ownership.

This is why I was asking about carburetor settings because I haven't been able to find any guidance on mixture settings or, at least, a starting point from which to work.

Had a quick play...screw the idle speed in(clockwise) will reduce the idle speed.
Screw it out and idle speed increases.
I was set at approx 3 turns out for an idle of 1100 if you believe the counters another couple of turns out took it upto 1300.

As you say the intent is you only have to adjust the idle speed screw...the two idling jets maintain "constant co"...assume that screw 12 on page B30 of the MR273 is set correctly..but this is a bit beyond my experience..Paul sage did my carb/clean rebuild about 10 years ago.

It is odd that the simple idling circuit is not working to at least get the engine firing (indeed you could have a load of issues with the other carb circuits..but that's down the road).

I might be lambasted..by the purists....but maybe a small spray of engine starter (easy start etc.) into the barrel as someone cranks could help you determine if your issue is electrical or fuel related. There is a lot of chat whether this damages engines..I don't know one way or another...

Getting the fuel to atomise and for there to be enough of a spark is a challenge..potentially old fuel, maybe some small vacuum leaks, and cold weather don't help....

[johnb]

I'll try the idle screw at 3 turns and maybe down to 2 as I found some information on the FAR forum suggesting 2 turns. The fuel is maybe 2 months old, borrowed from the lawn mower can and only recently added to the empty tank (tank removed whilst I've been doing the restoration). There could be vacuum leaks but hard to tell as I've used all new gaskets at the carbs and new seals between the inlet ports and inlet manifold. I guess I'll just check everything again methodically, step by step, and see what happens.

You mention the MR273. Is this the GTA manual? I have the French MDR for the A310.

You also mention two idling jets. Presumably you're referring to the one on the 34TBIA and the one between the geared quadrants on the 35CEEI?