Engine Starting

[Guest GeordieJim]

I have reached the stage where I can try and start the engine. Unfortunately all I get is a few pops and bangs. This is what I have got / done.

 

1. 2.0 L Pinto with ESCII system. Weber carb with auto-choke and stepper motor (all straight off a G reg Sierra).

2. All electrics are connected up. No air filter is fitted. Fuel is direct from tank (i.e. not through vapour separator - it didn't seem to work, I'll need to check that later) through a clear hose so petrol is flowing OK.

3. Cam belt timing has been checked and is correct (TDC mark on crankshaft and mark on cam shaft are in line).

4. Distributor timing has been set as follows - engine was set to TDC on no. 1 cylinder firing point (both lobes on cam shaft away from rocker arms on no. 1 cylinder). Distributor head was turned (by loosening retaining clip on block) until the rotor arm pointed towards the small notch on the distributor housing just to the left of the electrical connector. Ingnition leads where then put on in the order 1 - 3 - 4 -2 looking clockwise from above (i.e. no. 1 cylinder is just to the left of the electrical connector). Its a Bosch distributor.

 

When I try to start it I get ignition in the cylinders when the starter motor is going (the exhausts get hot) but the car won't start properly.

 

The stepper motor 'whines' when the ignition is one but I am told this is normal. Without the electrics to the distributor the car won't do anything at all. I thought it may be the auto-choke but I don't know how this is supposed to work. There is no voltage at the lead when the ignition is on.

 

I tried cleaning the carb (took the top off, cleaned the jets, etc.) but this made no difference. Though I couldn't figure out how to clean the nozzles that go into the air stream. I just blew it through from where I had taken the jets out.

 

Any ideas chaps?

[Guest gordon_macnab]

Sounds like the timng is out 180 degrees, i.e on exhaust stroke when trying to fire.

Rotate the engine by hand until the timing marks on the crank pulley are at TDC and the rotor arm lines up to the No1 timing notch, then rotate the engine again till the timming marks come round to TDC again and then loosen and rotate the distributor to get the rotor arm in line with the No.1 cylinder timing mark. You'll probably have to take out the distributor, rotate it and then re-fit it as it'll probably catch on the block and won't rotate enough.

 

If you think the choke is faulty just temporary fix the butterflies in a semi open position but this shouldn't stop the engine running or at least starting.

 

Gordon

[Guest GeordieJim]

Gordon,

 

I think I had it 180 before, as I had big flames coming out of the exhaust! However, I will check it again (or probably just try it through 180 and see what happens). I guess I may have had it 90 or 270 out previously.

 

In fact I could just give it a go in 90 increments and see if it helps. hanks for the advice.

 

One further question for everyone - what does the stepper motor do? Whenever the ignition is switched on the little plunger on the bottom of the motor goes in a little. After about 4 or 5 goes its fully in. Is this the position its supposed to be in when the engine is cold. The only way to get the plunger back out is to strip down the motor. Any ideas?

 

Bah humbug.

 

James

[Shandylegs]

James

 

Try following these steps do not take offence if i'm being too basic:

 

1. Disconnect fuel pipe & turn over to check petrol is being delivered (Use some form of catch tank). Is so and the spark pugs smell of petrol when removed this is not the problem.

2. Check you a have spark by removing a spark plug from the car to and using suitably insulated pliers hold slightly away from the head whilst turning over the engine.

If both of the above are ok then unless the carb is horrendously blocked, it can only be the ignition or cam timing at fault.

 

Cam timing:

generally if timing mark are aligned there should be no problem (But as a guide remove spark plug from nearest cylinder to cam belt (No 1) and using a screwdriver check the piston is at top dead centre by moving the crankshaft slightly each way (the piston will start to drop). Remove the screwdriver and rotate the crank approximately 100 degrees clockwise and check if the inlet valve is open on cylinder 1. If so the cam timing should be o.k.

 

Ignition timing:

Line up the distributor as you previously done then remove the cap note which way the roter arm moves then ensure the leads are corrected in the correct order 1-3-4-2 (You would not believe the amount of people who connect them wrong thinking the roter arm moves the other way round)

 

If the car does not start after this, while an acomplice attempts to start the car gently rotate the distributor small amounts in each direction until the car starts.

 

Hope this helps

 

Shandylegs :D

[Longboarder]

Stepper motor controls idle speed, acting like a variable throttle stop, controlled by the ESC11 unit. Also runs a little purge sequence when you switch off to stop running on. Can be replaced by a home made throttle stop bracket or disconnect the plug and adjust the stop on the butterfly arm. The electric choke uses a direct feed from the alternator of I think 6 volts using a blue/white wire and connected to a separate terminal from the usual trio of terminals that do the battery and ignition light (usualy 2 big ones and a 6mm one labeled 51, 51 and 61 respectively).

 

Nigel

[Guest GeordieJim]

Ah, that will explain where the unknown cable from the alternator went to. I haven't got the alternator connected yet so that explains why I haven't got any voltage on to the choke.

 

I presume that even if the stepper motor and auto choke were both knackered the car should still start (even if it ran rough).

 

Also, with the auto-choke, with the engine off and cold (as it is now) is the choke on and when the engine is running the power supply from the alternator heats up the auto choke and switches it off (what I am thinking is that the car should merrily start even if the auto-choke isn't connected to the alternator because it should be permanently on)?

 

Up the learning curve we go.....

[Guest Simon cooper]

Hi Jim,

Nigel is spot on about the choke wire (blue/white). You will however only get voltage when the engine is running. This is to prevent you leaving the ignition on (for maybe listening to the radio) and the choke comming off when it is not running.

It does sound like ignition timing. There are a couple of things that can cause this, even if everything does look right. Although the notch in the disi is a good guide, it cannot be relied on if the disi has been out. The notch is actualy a third timing mark for when you change the cam belt. Forget the notch for the moment.

Take No1 plug out. Disconnect the coil. Put your thumb over the plug hole and get someone to flick the starter for a brief second. You will feel the cylinder compress and push air past your thumb. When this happens go through the step of putting a screwdriver down the hole as previously mentioned and bring the piston to the top. It may have gone past a little or maybe not far enough, so just take the shortest route in either direction to TDC. Check ypour crank timing mark for accuracy. If it does not line up then the woodruf key has sheered (unlikely).

Now look inside the Disi. The vane inside is an inverted cup with 4 slots cut into it. At TDC there should be a window just opened at the pick up point. If you rotate the crank anti clock to the 3rd big notch (about 12 deg BTDC), the sensor in the disi should be right on the border between a window and a blade. if it isn't, then rotate the disi till it is. Then orientate the cap to see which segment of the cap the rotor is pointing to. It will appear to be just anticlock of perfectly pointing to one segment. That is where you plug in No1 lead. The rest go clockwise in you 1342 sequence.

That is now set "Staticly timed" to 12 degrees which is as close as you will get it without a strobe and as close as you will need to get it started. Lock the disi up and don't move it as you have covered every angle on the timing at this point. The only other 2 things left that now affect timing are the wires to the disi and the ECU. Make sure that the wiring is 100% correct. If they are wrong you will get your symptoms. If the two outer wires are "Arse about Face" then this will put your timing out by 45 degrees and it does not matter what you do with the rest, you will not get it to run. Also check that the earth to the disi wire is good. The rule of thumb for "Hall effect " disi's like yours is brown- earth, green-signal, red-live. These are the colours inside the disi, not ford loom colours. The signal wire will give you 6 volts on or off depending on the phase of the vane.

Hope all this helps, and appols if i have trod on anyones toes or stated what you know as obvious.

Simon

ps ANY PROBS, E MAIL ME DIRECT IF YOU WISH

[Guest GeordieJim]

Simon / all others,

 

Thanks for these excellent replies. I had sort of figured out it was the timing but was a bit stuck on how to get it right.

 

I probably won't get a chance to try out all of your suggestions till Monday (she's got me DIY'ing all weekend), but I give it a go on then.

 

I just like to say to everyone that I think this forum is absolutely excellent. I thought I was reasonably competent with cars but the amount I don't know has staggered me and without this forum I reckon I would have given up long ago.

 

Thanks again,

 

James

[Guest GeordieJim]

Gentlemen,

 

Thanks to your help I now have one fully operational engine. The problems I actually had were:

 

1. Timing slightly out (but surprisingly not far).

2. No earth from distributor.

 

I think the main cause was the lack of earth rather than the timing as it was pretty close, although I think it was luck rather than good management that it was close.

 

One thing I had to do was to open the throttle slightly by hand to get it to start and it still stops if I let the throttle close. Is this something to do with the stepper motor and could it be related to the temperature sensor?

 

Anyway, generally I am happy as anything. One more thing crossed off my to do list.

 

Thanks again for all your help.

 

James