Thread: I need some help, I broke my 87

Hi. Dont you hate it when you are just trying to do the right thing and then it all goes pear shaped.

If I was you I would just start from scratch. Even if you timing is still out you should have spark. Have you checked to see if you have spark? If you don't have a spark tester pull out an ignition lead (spark plug lead) and a spark plug.

Put the spark plug into the lead and earth the outside of the plug. Make sure it is earthed. Get someone to wind over the engine and see if you have spark at the spark plug you have removed. Dont touch it while winding the engine over or you might get a good zap.

If you have spark then check your fuel supply. You said that your fuel pump is running so I would assume that you have fuel presure as it was running before you got started. If you can get to the injectors you can pull off one of the electrical conectors and check for injector pulse at the connector. If you dont have access to an injector test light you can use a basic multi meter. when cranking the engine you should have a low voltage reading. Between 1 and 5 volts from memory depending on the injection system. Won't be a high reading as it will only be taking the voltage from an on/off pulse son not a constant voltage.

If you are satisfied that it is not fuel related, which it shouldnt be unless you have bumped or upset something else go back to your timing. The timing might be 180 degrees out.

You might even want to check that the timing is not 180 degrees out before checking the other stuff i mentioned.

Hope this helps

Hi davrac,

Thanks for the reply...
I've actually gone back to the start at least twice now already, down to the point of redoing the air gap in the distributor.

I am getting a nice fat spark at the plugs. I'm getting it to run pretty nicely for those 3 seconds :\ so am sure I'm not 180° out.

I'll get my meter on an injector if I can and look for the pulse- I never thought about doing that. Having thought about it I can only assume I've broken a wire somewhere or something like that which is killing my fuel.
I dunno, I've never been this stumped before on a vehicle.

Cheers,
Dave

My bet is 180degrees out.
Take out all the plugs and turn over the engine with a socket (clockwise ) while holding one thumb over number 1(front LH ie passenger side) plugole. You only have to do this for say 1/4 turn before.

When your thumb is popped off the plug hole you have found TDC firing.
Compare with the timing marks on the balancer .
see them? ___ no =180 out
yes=correct.

Regard s Philip A
I later thought that you also have to look at the dizzy to see which wire the rotor was pointing to when you have established TDC firing as the timing marks will line up 180 degrees out.

The fact that it runs is a sign that the injectors are working. There is one gadget which will kill the injection pulse and that is a vacuum switch at the back of the DS side of the plenum chamber. What this does is to interrupt the signal travelling from the negative side of the coil to the ECU. It's purpose is to cut fuel on high vacuum conditions, i.e. over-run, closed throttle. I have found them to be very touchy in their old age. The quickest fix is to disconnect the vac switch and bridge the two wires. Use your multimeter to check the vac switch and the wire to it from the neg side of the coil. The vac switch should go open circuit over about 25" vacuum. I usually bridge the vac switch out during the fitment of LPG because then it is one less thing to go wrong. It only reduces emissions on decel, won't affect economy much elsewhen.

Or just turn the dizzy around. (in response to phillipA)

Sounds like 180 degrees out to me too.

Hmm so I guess you have to figure out if it is the fuel or spark cutting out after start.

Might be hard to get a voltage on a meter if it is cutting out just after start. If you do get one you wont be able to tell if it is cutting out and is the problem or is cutting out because the engine has stopped.

Your main battery voltage isnt dropping to low after cranking is it. Not sure about rovers but some cars (eg commodores) will cut out after start because the main battery drops below 10 volts after cranking. (failing under load). The ECU needs to see adequalte voltage to keep things going. Not sure of this applies to rovers but.

Could try running a 12 volt supply to the fuel pump and bypassing the vehicle electrics to see if it keeps going. Could just remove the fuel pump relay and bridge it there.

Could also check to see if the coil / fuel pump etc are getting 12 volts after the ignition key retuns from the start position.

Good luck.... let me know how you get on.

Originally Posted by PhilipA

When your thumb is popped off the plug hole you have found TDC firing.
Compare with the timing marks on the balancer .
see them? ___ no =180 out
yes=correct.

Dont confuse camshaft timing 180 degrees out with distributor 180 degrees out. The Dizzy won't change your valve timing. Good way to find TDC # 1 if you cant find or see the mark on the crankshaft however.

I should have mentioned that when I clock the dizzy 180° I get nothing apart from an occaisional backfire.

Thanks for all the info though, I am going to run through everything I can hopefully after work tomorrow, esp the vac switch killing the injector pulse.