Help, Engine Will Not Start

[tractor]

mark i think you will find the the vr sensor is less than 2.5v well certainly when i was having trouble with the megasquirt sensing the cam sensor i had to adjust the ecu potentiometers to read less than 1v

[MarkBzero]

I was using the guidance and expected voltages from autosportlabs, towards the bottom on this page https://wiki.autosportlabs.com/MJLJ_V4_vehicle_installation_guideVR sensor, measure across VR sensor terminal 0v when not running and measure across Edis pins 5 & 6 approx 2.5v when cranking. Although another website suggested 200mA.

[MarkBzero]

OK new coil and crank sensor fitted still same issue, thinking fuel pressure might be too high going to fit regulator and gauge.

[tractor]

have you tried a bit of easy start it will help to confirm if it is a fuel issue

[MarkBzero]

have you tried a bit of easy start it will help to confirm if it is a fuel issue

Not yet I will dry off spark plugs tomorrow and let the engine breath then check with easy start.

[MarkBzero]

Easy start used, engine fired so something on fuel side. Waiting for fuel pressure regulator and gauge to be delivered, getting there.....

[MarkBzero]

Sytec pro flow fuel pressure regulator fitted, it made no difference. Eurocarbs are saying fuel at plugs it cannot be the new carbs, it runs when I put old 40s on.

Still waiting for edis unit to be delivered.

 

Totally lost with this one, any more ideas?

[knights_templar]

to break this down logically, it fires on brake cleaner, which takes very little igniting, bypassing carbs, and it runs on the old 40's but not on the new carbs.

 

It can have fuel at the plugs, but to much is as bad as to little, and it isn't as though the webber does not have a reputation for flooding.

Edited July 4, 2017 by knights_templar

[Bob Tucker]

Am I being a bit simple? If it runs on the old carbs, but wont even start on the new ones, doesnt that mean the new ones have a fault?

Also IIRC Zetec plugs get bugg**ed if they get wet....have you tried a new set?

[speedtripledan]

Sounds like carbs to me, are they dcoe? If so my 45.s on zetec had 140mains f16 tubes f8 50 idles and 36mm chokes and ran fine. What are your old carbs jetted at?

[knights_templar]

I would check fuel level, they are prone to the float valve sticking especially if they have been stood long enough for the fuel to evaporate away from the float bowls, the residue sticks the valves, causing a higher float level and with the cold start enrichment, basically a fuel tap, they just over fuel.

[MarkBzero]

to break this down logically, it fires on brake cleaner, which takes very little igniting, bypassing carbs, and it runs on the old 40's but not on the new carbs.

 

It can have fuel at the plugs, but to much is as bad as to little, and it isn't as though the webber does not have a reputation for flooding.

Thought the same, i switched off the fuel pump, removed spark plugs and put new plugs in. This could still be an issue but I suspect down to carb fault.

[MarkBzero]

Am I being a bit simple? If it runs on the old carbs, but wont even start on the new ones, doesnt that mean the new ones have a fault?

Also IIRC Zetec plugs get bugg**ed if they get wet....have you tried a new set?

Yep, I agree thats where I am now. Eurocarb are absolutely positive they will be OK. Thinking I will send back under warranty.

[MarkBzero]

Sounds like carbs to me, are they dcoe? If so my 45.s on zetec had 140mains f16 tubes f8 50 idles and 36mm chokes and ran fine. What are your old carbs jetted at?

Interesting you mentioned this, I was informed they were going to be sent with correct tubes, idles, chokes and jets. Sent order number via email today and they are going to check, I will compare to your figures. Thank you.

[speedtripledan]

Easy enough to remove and check it will be stamped on the components