Hi,

Getting very frustrated, looking for fresh ideas before I blow a gasket.....sell the bloody car....or set it on fire!

 

I have fitted a ST170 engine using Megajolt with original Ford Edis and coil pack. Everything was working, test drive down street was OK but the Dellorto twin 40's could not give enough fuel/air at idling and acceleration (jetted for 1.6). After speaking to webcon and pricing up parts I decided to order Twin 45 webers with 5 progression holes (specific for Zetec), fitted them and everything was running OK on test drive. Waiting for rolling road session, however after a trip to A&E with chest pains and a minor operation I had not touched the car.

 

Returned back to car after 6 weeks the car will not start. I am getting fuel and spark, I have also tried another coil and changed spark plugs. Switching at coil OK with test light primary coil readings 1.3 ohms and Secondary coil readings 10.38, I believe within parameter.

 

I have not touched any wiring, although next job is to make it tidy with cable covering. I do occasionally get back fire through exhaust and popping back through carbs, feels like timing, maybe over fueling. I have removed Megajolt plug and tried on Edis limp home settings but still no success.

 

I need your help, what other tests can I do before starting fresh with ignition and fuel system?

Edited June 23, 20178 yr by MarkBzero

if it was running before and you havent touched anything maybe a bit of easy start have you checked crank sensor or could be a loose earth

i did find fitting the edis very frustrating

Edited June 23, 20178 yr by tractor

You say you have fuel but have you checked that both carb's are fuelling. This happened to me after my engine rebuild, the engine would cough and try to start but no amount of churning made any difference. I was suspecting timing but nothing I tried worked. I enlisted some help and he gave it a hammering on the starter, moving the dizzy around but still no start. We took the plugs out and two were black,two clean. I had been checking that petrol was present on number one plug but not the others. Took the top off the rear carb and it was empty. Needle valve was stuck up. If you haven't touched anything then maybe this would be a good check to start with, just whip the top off the carb's after you have let them prime. Good luck

if it was running before and you havent touched anything maybe a bit of easy start have you checked crank sensor or could be a loose earth

i did find fitting the edis very frustrating

Thank you. I assumed because I have a spark the crank sensor was working but will take off tomorrow, clean and test. Earths will be quick and easy to test and I can easily add extra jumper leads to boost existing cables.

You say you have fuel but have you checked that both carb's are fuelling. This happened to me after my engine rebuild, the engine would cough and try to start but no amount of churning made any difference. I was suspecting timing but nothing I tried worked. I enlisted some help and he gave it a hammering on the starter, moving the dizzy around but still no start. We took the plugs out and two were black,two clean. I had been checking that petrol was present on number one plug but not the others. Took the top off the rear carb and it was empty. Needle valve was stuck up. If you haven't touched anything then maybe this would be a good check to start with, just whip the top off the carb's after you have let them prime. Good luck

I am hoping with brand new carbs they are working but it would not be the first time I have bought something that did not work.I will take the tops off carbs and check needle valves and float levels again. Spark plugs are new, fairly clean with minimal running to check carbon build up. Thank you

if the crank sensor is dodgy it may still spark just not at the right time or miss a spark

if the crank sensor is dodgy it may still spark just not at the right time or miss a spark

 

i have a spare and will compare values with multimeter and swap over. I will go through tests tomorrow, thanks.

OK just finished in garage and looked at suggestions above.

Both crank sensor give same readings on multimeter and when turning over - is this pure coincidence could they both be faulty?

All earths checked and cleaned.

I can confirm all carbs getting fuel, and needle valves free to move although one of the floats setting was slightly off.

New spark plugs from Ford fitted - no difference.

 

Next steps order new crank sensor, new coil and edis unit.

 

Any more suggestions?

Coil and edis are easy to find but crank sensors vary from £9 to £62 what's the difference and why?

Whilst drinking a nice cold beer in the garden and searching the Internet I have found that the crank sensor should provide voltage 2.5v at edis pin 5 + 6 when cranking also another bonus the VVT unit light will flash 3 times consecutively if it is not receiving a proper crank signal.

 

More checks tomorrow, might narrow down what I need to buy.

Can petrol be off from sitting a while?

Can petrol be off from sitting a while?

I have heard about that, it had about 1/4 tank and was running 6 weeks ago so I hope thats not the case.

I will however top up with fresh fuel asap.

Whilst drinking a nice cold beer in the garden and searching the Internet I have found that the crank sensor should provide voltage 2.5v at edis pin 5 + 6 when cranking also another bonus the VVT unit light will flash 3 times consecutively if it is not receiving a proper crank signal.

 

More checks tomorrow, might narrow down what I need to buy.

Not getting any voltage reading at crank sensor. Going to get new sensor on Monday.

No voltage at the wiring harness into the sensor or no voltage coming back from it?

vr sensors dont have a live feed only hall sensors the zetec and st170 zetec are all vr sensors