Misfire worse after installing Magnecors??

KirkJames · 20-10-11, 04:03 PM

I have had a slight misfire for a while now and I have changed spark plugs and it was still the same now after putting Magnecors on it seems to be worse. Any ideas, and what can I try next to pinpoint the misfire. I am really getting a little down about this now. To make matters worse I can't get my IAC valve off as the screws are knackered and don't know how to drill them.
New post cat lambda sensor going on tomorrow as that came up on two separate occasions on my code reader.
Here's some pics,

fastmike · 20-10-11, 04:07 PM

check the wiring loom to the ECU.... they have a habit of chafeing through on the battery tray

KirkJames · 20-10-11, 04:14 PM

I will have a look, thanks Mike, and see if I notice anything sinister.

peterzs · 20-10-11, 05:13 PM

What do the coil packs do, if they are like the old coils, could one be faulty???

fastmike · 20-10-11, 05:31 PM

Quote:

Originally Posted by peterzs

What do the coil packs do, if they are like the old coils, could one be faulty???

Yes , could well be a coil pack...... I,de check those after looking at the ECU wiring loom

daytona365 · 20-10-11, 07:04 PM

Quote:

Originally Posted by fastmike

check the wiring loom to the ECU.... they have a habit of chafeing through on the battery tray

There's nothing worse than a bit of chafeing!!!!

KirkJames · 20-10-11, 08:18 PM

Ouch, chafeing lol. I have changed the coil packs already and I am quite certain it isn't that as the misfire was the same before and after. On the plus side, I have some spare coil packs.
I have had a couple of members saying it may well be the Lambda sensors. I have a new one going on tomorrow (Post Cat) which is the one which is coming up on the fault code reader.
Do you think that could make the car misfire. It also seems to 'surge' ever so slightly as well after you take your foot off the gas. Any ideas?
I have changed the TPS as well so not that.

fastmike · 20-10-11, 08:35 PM

Crank position sensors can play up too..... but I,de check as many things as poss before spending any money.

So many things can be checked with a digital ohm meter... owning one is a must imho

KirkJames · 20-10-11, 08:45 PM

Quote:

Originally Posted by fastmike

Crank position sensors can play up too..... but I,de check as many things as poss before spending any money.

So many things can be checked with a digital ohm meter... owning one is a must imho

I wouldn't know where to start or what I was looking for mate to be honest. I take it you mean to see if there is the correct amount of current going through things??
Where are the crank position sensors and what is there function?

zsserbia · 20-10-11, 09:17 PM

Crank position sensor I'd exclude for the moment because chances are it wouldn't start at all... Is the misfire present just at idle? If not, is a cloud of black smoke following you? Anyway, as fastmike says, ohm meter is a good point to start with. I'd check the injectors first and wiring to them. Injectors should be 13-16 ohms. Lambda sensor heater should be 6 ohms. As said, it could be the culprit as well. Check the spark @ each plug to see if any is different than others. Take the spark plugs off and check if any of them is oily... Pretty straight forward.