Chevette Owners Group

Non Members Area => General Discussion => Topic started by: TrevsChev on Sep 26, 2017, 12:21:46

Title: Std 1256 Engine turns over but will not fire
Post by: TrevsChev on Sep 26, 2017, 12:21:46
Hello Everyone,
I have rejoined the club (and paid lol) after a few years absence. No change of car just other priorities in life.
Each summer I start my garaged 1256 std Chevette and check all is working ok. This summer I cannot get her to fire.
The engine turns over with a charged battery and I have a spark across the HT leads to the spark plugs. (test on engine block)
I have petrol reaching the carb and each of the spark plugs. I am continually drying and refitting the plug ends which are wet & smell of pertol.
I have cleaned and set the spark plugs gap to 1mm, and the distributor points to 0.5mm.
With the distributor cap removed, I have a spark at the points and the rotor arm is moving anticlockwise when the engine is cranked over.
I have replaced the condenser and the coil.
Am I correct in saying the Timing chain is working ok, if the distributor shaft & rotor arm are rotating when I crank the engine?
I removed and cleaned the two earth strap straps one from the from the battery and the second from the engine block to the bodywork.
Any ideas why she will not fire?
Look forward to hearing from you
Cheers, Trev (Norfolk)
Title: Re: Std 1256 Engine turns over but will not fire
Post by: Ashley on Sep 26, 2017, 12:31:35
Stale fuel??
Title: Re: Std 1256 Engine turns over but will not fire
Post by: mick on Sep 26, 2017, 12:41:45
I agree with Ashley, stale fuel. I Would always try fresh fuel if the car is stood for more than a few months. Glad to have you back, did you remember your password in the end ?
Title: Re: Std 1256 Engine turns over but will not fire
Post by: scotty on Sep 26, 2017, 14:55:10
Spark timing maybe? Leads on in the wrong order?  1342 is the order. Number 1 and 4 should  spark when crank pulley timing marks line up.
Title: Re: Std 1256 Engine turns over but will not fire
Post by: TrevsChev on Sep 27, 2017, 10:46:50
Gents, Thank you for your help.
I have checked the HT cables 1,3,4,2 sequence from engine to distributor are correct. Possibly the timing has moved. I could try a static timing check from Rotor arm pointing to No 1 with the timing marks aligned and a test lamp.
However the other recommendation Stale fuel! Interesting! This could be the answer!
You may smile at this, I still have under quarter full of 4 star petrol in the tank from filling up some 15 years ago. Interesting that she still started last year.
OK, where is the best place on the car to drain the fuel from?
And what fuel and additives do you recommend to use?
Note the engine has the original valves with no modifications.
Cheers, Trev
Title: Re: Std 1256 Engine turns over but will not fire
Post by: scotty on Sep 27, 2017, 14:04:10
To drain disconnect the fuel pipe from the tank put on a temporary pipe and drain it into a tin (or several). In a saloon the tank is behind the back seat hidden by a bit of cardboard.  Why don't you just squirt some new fuel into the carb mouth and see if it fires. Take the airfilter element out to do this.
Title: Re: Std 1256 Engine turns over but will not fire
Post by: mick on Sep 27, 2017, 18:13:06
Or instead of fuel, carb cleaner works well, watch out for backfires though. I wouldn't use easy start on a old engine though.
Title: Re: Std 1256 Engine turns over but will not fire
Post by: TrevsChev on Oct 11, 2017, 17:01:48
Mick/Ashley/Scotty,
Getting closer to starting her again. I removed the Air cleaner and squirted several seconds of carb cleaner into the mouth of the carb. Turned the key and she fired, just the once, but she fired. I did try numerous times squirting small amounts into the carb, but she would only fire the once each time.
I will empty the tank of 4 star and introduce her to a new diet of unleaded petrol, and see what happens!
Thank you for your help chaps.
Title: Re: Std 1256 Engine turns over but will not fire
Post by: scotty on Oct 11, 2017, 19:41:47
An old trick for reluctant engines is to heat the plugs up under the grill to dry off any conductive moisture then fit while still hot . As for squirting fuel in jam the carb piston up with a screwdriver to ensure the fuel gets to the manifold. - Scotty
Title: Re: Std 1256 Engine turns over but will not fire
Post by: hsrwannabe on Nov 16, 2017, 00:41:27
I would say its carb related (floats stuck open so fuel just passing straight into the venturi) and flooding the engine wetting the plugs. Clamp the fuel pipe.to tge carb and crank hwr without choke for a little while, clean and dry plugs then spray some easy start into the inlet side of the carb as you are cranking it over, if it fires it aint timing. Could be stale fuel but I would have thought it would still fire. Blocked carb or stuck down floats is my bet
Title: Re: Std 1256 Engine turns over but will not fire
Post by: parko on Nov 16, 2017, 19:37:14
i left shedvette standing for a long time and it wouldnt start no matter what.so i got a small rag and poured a tiny amount of petrol onto it and put it in the end of the air filter housing and it fired up straight away.possibly a dangerous thing to do but i was getting frustrated with the bloody thing.
Title: Re: Std 1256 Engine turns over but will not fire
Post by: TrevsChev on Jun 26, 2018, 16:00:05
Hello Everyone,
Pleased to say Ashley & Mick identified the reason the 1256cc engine would not fire. Stale fuel. I drained the remains of 4 star petrol that had been in the tank for the last 20 years (lol). Added a gallon of unleaded and after finally identifying and freeing a sticking stromberg carb piston she fired up immediately, and ticks over nicely.
Thank you Ashley & Mick
Title: Re: Std 1256 Engine turns over but will not fire
Post by: mick on Jul 02, 2018, 15:25:02
Excellent 👍🏻 You’re welcome.
Title: Re: Std 1256 Engine turns over but will not fire
Post by: John PH on Jul 05, 2018, 23:04:48
when mine had trouble starting it was because the piston rings are worn and exhaust gasses wear being breathed into the carb pull of the hose from the top of the engine to the air intake see if it fires up.
 
Title: Re: Std 1256 Engine turns over but will not fire
Post by: Bill on Jul 10, 2018, 10:05:14
lob a large bottle of redex in the tank too, that will help clean out the tank and carb as well as give the inlet valves and rings a clean..