Struggling to idle / misfire 16v K-jet *Update*

Righty Ho.

I have read (for many hours) various posts similar to my issue.

Freshly Build up 16v (1900cc) so all new parts like plugs, leads, sensors etc

-Timing is bang on
-Coil has spark as do the plugs
-Air flap is set
-Fuel pressure is good (5.2bar system)
-Metering head is good and all injectors spraying as should.
-WUR pressure is approx. 1bar on cranking
-Accumulator is new Bosch
-Pump is working
-Pump check valve cleaned and working
-Filter is new
-Cold start valve functions
-Idle valve buzzes away
-Throttle switch / Throttle body is set and functioning
-Vacuum lines are connected
-Various wiring checked and new connectors fitted etc due to age
-All new sensors in the side of the head and rear of head (small ones)
-Large coolant sensor is the old one (Could it be this??????)



Once the battery is charged (new battery with 8amp charger connected) the engine will struggle to fire, if it catches it'll stall within 5secs, I have had to turn the ignition on/off 4-5 times to get it to initially fire up.

The engine as said is fresh and hasn't been run since the rebuild.

Am I missing anything.

I need to try later (once battery is charged)

-Un plug over run valve and try to start
-Connections on side of head for security

Any pointers are welcomed with open arms, want to get this running, been over 3 years doing full restoration.

Much thanks

 

does cold start valve inject fuel during cranking ?

remove the spark plugs after cranking, are they wet or dry ?

 

Yes, wipped it out and sprays whilst cranking

Plugs were dry after 30 odd minutes of trying on and off to start it, pulled them all out and were dry

 

air flap rest position is set, what about freeplay between air flap lever and metering head plunger ? do you feel resistance when lifting the air flap ?
there must be some freeplay, you dont want the injectors to spray fuel with fuel pump on and air flap in rest position, but as you lift the air flap a little injectors must start spraying.

 

It was set with 20mm gap as per pluger position but i will check it again to be sure

 

I

Yes was good read and spot on

I think thats the likely issue, not mangaged to find the default or basic setting for the idle screw as yet or if there is one eg all the way in then x amount out.

Did set it to the same as another TB on my 9a 16v but didn't make much difference.

O ring is ok and sealing too

 

Yes ive had the pleasure/misfortune to have had to do that

 

Its running yey!!!!

Took many tweeks of the idle screw and the CO screw.

Little bit of a idle hunt only minor but we can work with that, now to let it cool and the battery to charge again

 

Few niggles (as expected) got a slight misfire and the rev counter is pretty erratic.

The only thing in haven't replaced was the hall sender inside the dizzy, it had a broken plug (glued back on) the wires were ok and worked before. I had the dizzy apart to change the seal and didn't replace the sensor due to the cost.

Would the hall sensor cause this?

Thanks

 

So further findings.

New hall sensor installed, its a new type with no wires going around the shaft like the old one, its just one unit, bosch and from ECP at 45 quid.

Only change was the rev counter is now working normally.

So...

- All vac hoses changed
- All intake pipes/hoses checked and tight
- Zero air leaks as ive sprayed brake cleaner all over with no effect.

Tested the injectors flow rates, all within 2.5ml of each other at 80ml over 40 sec with a mixture of good / bad spray patterns.

System pressure is at 5.4bar
Conrol pressure is a 3.2bar and steadily goes up from 1bar cold to above.

The engine will idle 1100 rpm area +/- 100 odd rpms but its lumpy, pick up revs to 2000+rpm and all is good, no lumpyness and revs clean.

The only thing i can think of is the injectors at idle?

I bench tested them at System pressure and ran cleaner through them, they hold pressure as in dont dribble one off.

However a few times when i was adjusting the metering head not at full flow there was a few dribbles where is should be a pattern.

Ordered some merc brass units, I'll just need to remove the new inserts and/or just block the nipple/breather pipe.

Can't be anything else, everything is working and checked again and again.

 

Solved

Spare fuel metering head fitted made a large improvement and final fix was replacing all the electrical connectors at the coil.

 

Good result,well done,electrics are my first " go to" but certainly not my strong point,CIS metering heads are normally pretty good but any water passed will ruin them quick smart and lack of use is no help also.