Hi, My zed has started missing on number 1. It runs fine when cold and sometimes keeps running well for quite some time. After it heats up however, it regularly drops number 1. I have cleaned up the plugs, checked the coil pack connectors and removed number 1 spark plug while hot and found a solid spark. what does everybody reckon? cheers z
Yes, Injector connector looks shabby but Ive cleaned it up and definately making a connection. I want to avoid pulling the plenum as the motor is not going to be in it for long. Can I wire the injector directly into its output on the ptu to check if the wires are breaking down?
PTU has nothing to do with the injectors. PTU gets signal from ECU, then sends it to the coilpacks. Injectors are switched directly off the ECU AFAIK.
thats a very good point... would have been interesting connecting up the injector to the PTU LOL so if the cylinder fires when cold but not when hot, could the injectors simply need a clean up or does it sould more like wiring. If it stops working and you turn it off and let it cool down for a few hours then its all sweet again.....for 10 mins or so.
I am definately going to do that but wouldnt it normally be the case that compression would be lower when cooler and increase as temp rose?
Depends why compression is low I think. It's definitely possible to have a misfire caused by compression issues than only shows up once the engine is warm though.
I would say it's the coilpack. You say you removed the spark plug coilpack and could see it sparking, but that was in open air? If the coilpack is weak it will stuggle to fire properly in the engine and as it heats up it gets worse. Try swapping the coilpack with one of the other cylinders and see if the misfire moves to that cylinder.
Ahhhhhh Check your injector connector. It will be corroded, dirty/broken or all three. Clean the terminals (both male and female), retension the female terminals and reconnect or just replace with a new connector. extremely common.
Hi all, I have pulled the plug at operating temp again and found a lack of any thing resembling a spark. Let it cool down and spark is back again. The problem is also intermittent at operating temp. I replaced the injector connector and no difference there although it did require replacement as it was corroded. so...I checked back along the harness and found that at both cold and hot temperature, the misfire could be started and stopped by moving the harness up and down in its mountings. I have isolated the problem to the junction at the back and on top of the plenum. When hot, it is significantly harder to stop the misfire by moiving the harness around so Im thinking that a wire has gone bung in there somewhere? Is it possiblke to simply open the harness up and replace the stuffed bit of wire? is it possiblke for the wire to be stuffed on the inside even if not on the outside? And, does the wire color at the coil pack continue through the harness? regards z
Yes, you can replace just the wire in question. The colours continue all the way from the ECU to the PTU, and from the PTU to the coilpack. It's not uncommon for individual wires to break in the loom, specially once they are moved around a bit.
cool, is there any way of telling whether the broken wire is on its way to the ecu or from the coil pack to the ptu etc, at that junction?
It's a bit trickier as it's a intermittent problem, but you can normally pick it up using the continuity test on a multimeter. So get the pinouts for the ECU and the PTU and have a play.
Yeah ... you could do temporary bypass to check it ... from the cylinder to the ECU .... here is ECU pin out code I use .... I had the same sort of problem and it turned out to be a injector connection issue cause it to be wide open all the time .... Image c/o Slashman Let us know how you get with solving it.
To provide closure on this I stripped the wiring harness of its cover and replaced a couple of the doidgyer looking wires and found no change. I noticed that as I moved the harness through the fire wall, different cylinders would drop and carry on etc. I checked the ecu connection and although it looked as if the big plug was in, I discovered that it was infact not tightened up and was a little loose. After I pushed it in properly and tightened the bolt, the car stopped playing up and runs well. As I was taking the car for a test run with a smile on my face, I slowed down behind a car in front and the brakes stuck on:bash:....... They freed up after a pump or two but have been sticking on intermittantly ever since. Im going to check the piston movement and give the system a service but if I cant get it sorted then look out for my ' fixing the brakes' thread. cheers for the help z
