120 Series 4 ltr V6 ignition coil pack resistance check

[Lubeit Lurker Find all posts View Profile Close Lubeit]

Hi All,

Im in the process of troubleshooting a progressively worsening rough running of my 2004 120 Series Prado with 4 ltr V6 Petrol engine (also running lpg).

I bought a Max Ellery Toyota Prado workshop manual from Supercheap today. It covers 90/120/125 series Prado, including all engines and derivatives.

I have pulled all 6 ignition coil packs and spark plugs to inspect and measure.

However, I'm not confident in the resistance values published in the manual as all 6 of my coil packs measure vastly different to the quoted figures but they all measure very similar values between each other. The manual is pretty vague in detail as it covers so many engines and derivatives.

After searching this site as best as I could, my question is does anyone have known good data for expected resistance values and pinout info for these ignition coil packs?

Thanks,

Lubeit.

[Guest Close Guest]

I'd be replacing spark plugs if you have them out.. Not worth measuring them. They are consumables. Rough running (especially with LPG) is often spark induced. I'd replace the plugs first making sure they are gapped to spec. Then reinstall the coil packs in different locations. Have you cleaned the MAF? Chnaged air cleaner?

[Lubeit Lurker Find all posts View Profile Close Lubeit]

Hi Piggy,

Thanks for the reply. Yes I cleaned the MAF and pulled the air filter temporarily to see if it was the cause, but no change. I believe I have found an issue in that one of the spark plugs showed contamination around the ceramic on the outside of the plug (ie not the combustion chamber side) and its insulation resistance was breaking down when I checked it with my megger at 1 KV, whereas the other 5 plugs looked clean and their insulation resistance did not break down. I have thrown in a whole new set of plugs.

I guess I just wanted to ensure the serviceability of the 6 ignition coil packs before I reinstall them and restore the intake plenum. It's quite a bit of work to get to the packs and plugs on the LHS of the engine and would be good to confirm that the packs are good before I chuck it all back together.

I guess I'll throw it all back together then and see how it goes. Hopefully it was just the plug. I have not seen any engine light come on so that also probably points to it being plug rather than coil pack.

Cheers,

Lubeit.

[Guest Close Guest]

Umm. You can remove the coils and plugs without taking anything off the intake systems on a 1GR. Socket extension bars and uni joint is your friend here.. Did all 6 of mine the other week in like 30 minutes, only removed one small hose from the passenger side of engine and tucked it out the way.