spark plug condition?

[XR6TTUB]

does you car shudder or misfire at idle aswell?

[MurdoK]

Sometimes it has a miss other times it doesnt.

Have done a lot of maintenance and small repairs lately to the fuel and ignition system with out great success but the cam timing has me worried going forward.

Ive been told too heavy an oil can do weird things to the cams on start up and may see a correction on my problem but I doubt that would correct -11 that you were seeing

Edited 04/01/18 01:10 PM by MurdoK

[XR6TTUB]

I see that figure all the time, only time is runs great is cold start to about the 1st line on the temp gauge (around 60-70c)

after that the misfire/missing comes along, at times it would run awesome when hot, at times it just does it (mind you it is irregular aswell)

As a mechanic myself, I've never encountered anything to this magnitude.

 

Usually,when it starts to pull timing (retarded) then something has set if off and off it goes into limp mode (first thing I looked at was the knock sensor)

swapped that out and nothing changed

 

I've got like 4 sets of coils sitting in my spare parts drawer, 2 sets of standard injectors,7 TPS and 3 whole Tb's

changed the fuel pressure regulator,new fuel filter and next will be fuel pump (only hard thing to test, as its hard to get fuel pressure tester hooked up)

tested oil pressure and that was @ factory reccomendations

Tested for headgasket leak with testers etc

Compression test 200psi all 4

leak down test within 5%

 

To be honest with you, Only thing I cant think of is

1.Issues with ecu, faulty Injector or coil driver

2.Internal mechanical issues, burnt valve etc

 

hence why I was saying to keith , I have no more hair to pull out LOL

 

kenny

[MurdoK]

I understand the pain. That list is as long as the one im ticking off. Im finding small things along the way but nothing that stands out and fixes it. Painful process of elimination.

Good luck 

[XR6TTUB]

have you attempted to bring the vehicle to a reputable shop to diagnose? if you did what was the outcome or diagnosis?

[MurdoK]

Yeah the car has been to the tuner. A few small issues but I havent been able to give him the time because of xmas and holidays etc for him to properly go over it so that's next for me

[4321]

This might be old fashioned but stick a vacuum guage on it, pick up vac from a central point (not from pressure reg) At idle it should be reasonably steady- not fluttering, you'll need a cheap vac guage not a boost/vac guage because they do not respond quick enough. Check your idle reading then bring the revs up to about 2000, drop back to idle & see if you instantly get the same reading not needle flicking & then settling down All things being right it should hold a steady reading at idle if the engine is mechanically sound, a low reading is in the tune (you've checked the valve timing & done a compression check) If the needle flutters & then settles down look at valve seating (springs/ guides etc) If it had a burnt valve it would show up in the comp test. Plug the scan tool back in & start going through live data to see what the ecu is seeing from the  knock /o2/ map sensors you might be chasing a crook earth. By looking at live data you are seeing what the ecu is seeing & I find this helps with diagnosing the problem

 

If its idling to fast the ecu will pull timing out to try to drop the idle speed If you tried another T/B check for air leaks The ecu use's multiple maps for timing calculations- cold start, ECT, IAT, knock, even the o2 sensor

[giant193]

hi all, long time lurker first time poster

 

the compression test you did, it should be 180psi, sounds to me like that's a non turbo block, I think they're around the 200 mark if somebody could confirm?

 

cheers,

ben

[camo86T]

200psi doesn't mean non turbo block if that's what you're saying.

200-205psi across all 6 on mine a  couple months ago.

[MurdoK]

As long as the same crank process and amount for each cylinder I thought it was all good to getting a good reading?

I had 180 -175 (verified again by a workshop) across 6 using 5 cranks and the process stipulated by the repair manual