Another Non Starting Mi16

[roote 0]

hi all,

im now at a total loss of why it wont start, its an mi16 on 2 row std ecu.

ive checked and have the following

 

lives at coil all 4 wires

live at injectors

spark with plug against earth

fuel on plugs also tried easy start as a last resort.

ive also checked coil and ignition amp on another car and it ran fine.

 

symtems are if left over night it will fire once then nothing, if i rest the plugs in the plug holes, it will fire as i stop cranking.

its as if its a leak spark or not getting full voltage when cranking, ive even tried using a separate battery for the starter so ignition side is no on load of the starter.

 

so suerly if i have petrol and spark i should have fire, any advice would be appreciated.

 

 

 

[Kane 34]

So is it firing and cutting out or not firing at all?

 

If its not firing at all could possibly be a duff CAS. Had this happen to me all of a sudden. Car would turn over but wouldn't fire at all, changed it for a known good item and fired up first time.

[Tom Fenton 1,541]

Yep I would also try a crank sensor although usually they are very reliable. Easy enough to try though.

[roote 0]

hi, sorry, changed crank sensor

ive had a load of trouble so ive swapped to a newer loom as old 1 was a bit tatty, but the same symptoms, now comes the truth,

 

a sparky has had a go and came to the conclusion it was the ecu not giving the fuel relay an earth so put a perminant 1 to it (orange wire)

 

also im not getting an earth to thew cold start solernoid so linked an earth to this, still no joy, i may be thinking that has this caused any back feeds to the ecu and buggered something ?

 

thanks for the replys also

Edited January 23, 2016 by roote

[roote 0]

hi all,

always check the basics first,

turns out all was fine but the compresion is down, 58, 62, 61, and 82 psi, this is on new liners, piston and rings, looks like all the chewing over hasn't done it any good.

 

has any one any readings on fresh engines after a rebuild before first start up ?

[welshpug 1,657]

throttle open or closed?

 

has it been run in?

[roote 0]

throttle closed and new as in never started but turned over lots due to a problem with rebuild, the head needed to come off for head work then back on.

 

could the bores have washed ?

[welshpug 1,657]

throttle should be open when you do a compression test, I doubt it's washed the bores.

[roote 0]

ive not seen anyone open the trottle when doing a comp test befor, but ive just checked with it open and got the following 60, 65, 75 and 82 psi so no real difference.

[kyepan 291]

This sucks, but you'll figure it out, just stay positive that once you know the issue, it's fixable.

 

If it's a gentle leak and you think it's going down the bores and it's washed, get a teaspoon of oil into each cylinder after leaving it with the plugs out to dry, granted the tilt of the engine will mean it will only hit the back walls, but it;s better than nothing, and will get knocked about once you turn it over, see if the compression improves noticeably when you retest.

 

I would like to be able to say i know the difference between the compression on a rebuilt engine that's not been run and one that has... but i don't

 

However if you're dealing with first start rebuilt Mi with no compression i do have something to think about. When i rebuilt my MI I pre filled the lifters with too much oil, causing the valves to stay open a little, resulting in very little compression and a non starting car..., it sounded like an engine with a broken cam belt, just whine and little compression.

 

If you reconditioned the lifters, or bought aftermarket ones, that might be why you've got bugger all compression.Some people managed to compress enough oil out of the lifters to get it to start, but i had to pull them out, bin them, and then get the original Peugeot ones back in, then it started on the button.

 

A leak down test will tell you if it's loosing pressure when the valves should be closed, in my case we realised they must be open because the rate of pressure loss was way to high to be rings. leak down tester requires the tester and an air source that essentially pressurises the cylinder when its got the valves closed, so you need to fill it with air on TDC between the inlet / ignition stroke when all the valves should be closed. Then measure the pressure drop over time.

 

if it's got little compression check the simple stuff.

 

Take the covers off the cam belt and inspect it for damage.

put the pins in and make sure it's not jumped a tooth and they still line up.

Turn it over with a spanner twice and check they line up again so you know it's not the wrong length belt and it was just a fluke they lined up the first time.

If it's on verniers and hotter cams recheck the lift on the inlet and exhaust lifters at TDC to make sure it's timed correctly, get a second man who knows what he's doing to verify you've not read it wrong.

Does it turn over evenly by hand with a spanner, does it feel ok ow weird (when you factor in compression) , is it making any dodgy noises..

 

At this point if you think it's leaking from the top, because the leak is too rapid, i'd be thinking about checking its got the correct cams, and checking valves for straightness, which is obviously a head off job.

 

 

 

 

who rebuilt the engine?

did they use assembly lube on the rings or normal oil, and did they set the rings with the gaps at 120 degrees of each other to maximise the initial compression.

Where did the head come from, was it complete, does it have history, was it off a working car, did you build it.

Were the valves checked for straightness (this can be done in a drill held in a vice, but is more accurately done your machinist/engineering place).

 

hope this helps a little, been here and got the tshirt, it's worth the effort even if you're tearing your hair out right now.

Edited January 25, 2016 by kyepan