Losh's VR Ute build thread

[losh1971]

On the DFI you use heatsink paste, which I guess does the same thing.

 

[Skylarking]

Just some food for thought @losh1971.

Heat is the enemy of electronics.

As such one must wonder whether mounting the DFI module to a cooling plate which is itself bolted to the idler pulley (next to the water pump at least in a VX) and head would provide a path for heat to flow from the engine to the DFI mounting plate. If such a heat path exists, then the question is whether the cooling effect provided by the wind caused by the accessory belt hitting the underside of the plate is enough to account for such a heat path in an older hotter running engine. The question of whether oily muck on the underside of the DFI mounting plate can also act as an insulator making cooling all the more of a problem could also be an issue.

As is, nothing really required the DFI to be mounted where it is and it can be relocated to a cooler location away from oiling issues... This may just be the reason someone can justify an OTR CAI Or, if original aesthetics are preferred, a little fan can be made and mounted on the idler pulley to kick up a bit more of a wind storm to improve on the cooling ability of the DFI mounting plate or cold air brought in via some plumbing. Keeping the underside of the DFI mounting plate clean also couldn’t hurt. Heck, a good welder can even increase the size of the cooling ribs on the underside of the plate if there is space (keeping in mind the need for bolt access).

Otherwise if heat isn’t the real cause of the problems experienced by DFI modules, it may be vibration is the culprit in which case relocation may be the better approach.

PS: the current DFI placement may also experience some heat from the exhaust headers but there is supposedly a unicorn rare shield that supposedly resolves this heat source.

 

[losh1971]

They can be moved to the middle of the manifold I believe? IIC they move the coils there when you fit a side mount SC or turbo. Thing is I had a pretty good run for over two years before I started getting major spark issues. The DFI that as on the ute was replaced with an $80 eBay DFI and it lasted until the coil died and took it out. Since then I have had a fair few problems.

 

[vc commodore]

Just some food for thought @losh1971.

Heat is the enemy of electronics.

As such one must wonder whether mounting the DFI module to a cooling plate which is itself bolted to the idler pulley (next to the water pump) and head would provide a path for heat to flow from the engine to the DFI mounting plate. If such a heat path exists, then the question is whether the cooling effect provided by the wind caused by the accessory belt hitting the underside of the plate is enough to account for such a heat path in an older hotter running engine. The question of whether oily muck on the underside of the DFI mounting plate can also act as an insulator making cooling all the more of a problem could also be an issue.

As is, nothing really required the DFI to be mounted where it is and it can be relocated to a cooler location away from oiling issues... This may just be the reason someone can justify an OTR CAI Or, if original aesthetics are preferred, a little fan can be made and mounted on the idler pulley to kick up a bit more of a wind storm to improve on the cooling ability of the DFI mounting plate or cold air brought in via some plumbing. Keeping the underside of the DFI mounting plate clean also couldn’t hurt. Heck, a good welder can even increase the size of the cooling ribs on the underside of the plate if there is space (keeping in mind the need for bolt access).

Otherwise if heat isn’t the real cause of the problems experienced by DFI modules, it may be vibration is the culprit in which case relocation may be the better approach.

Makes you wonder why alot more people aren't experiencing the same issue?

Oh and yes what you have posted makes alot of sense in terms of preventing premature failure

 

[Skylarking]

Makes you wonder why alot more people aren't experiencing the same issue?

Don’t have a V? series V6 but from what I’ve read it’s a common problem...

What makes me wonder is how in older cars with points driven distributers, a single oil filled coil lasted for decades with minimal issues. The one coils magnetic field was created and collapsed to service all spark plugs within the engine. The more modern V? series V6 in comparison has one coil for two spark plugs and doesn't seem to last as long or provides some feedback to the DFI and one or the other or both die....

 

[vc commodore]

Don’t have a V? series V6 but from what I’ve read it’s a common problem...

What makes me wonder is how in older cars with points driven distributers, a single oil filled coil lasted for decades with minimal issues. The one coils magnetic field was created and collapsed to service all spark plugs within the engine. The more modern V? series V6 in comparison has one coil for two spark plugs and doesn't seem to last as long or provides some feedback to the DFI and one or the other or both die....

Maybe I have missed it, but I have only read about it a couple of times.

 

[losh1971]

TBH I'm not convinced the issue with spark on my ute is even the DFI. I think it's more likely the CAS but the bloke couldn't find his testing tool and when the replacement DFI got the engine running he thinks "oh yeah definitely the DFI".....

IMHO I think pulling the DFI plug and putting it back on might have had the same result....

 

[Skylarking]

pulling the DFI plug and putting it back on might have had the same result....

cheap mans contact cleaner

 

[losh1971]

cheap mans contact cleaner

Yeah and that is something I was thinking I will do next weekend. I have contact cleaner at home in the shed. I did that with my ALDL plug and put a couple of sprays of WD40 and pushed in the ALDL cable a few times to work it in. Certainly helped when that was having problems connecting with my old laptop.

 

[losh1971]

I'll add that tomorrow I am hoping to go an see an auto electrician and see about repairing the engine harness. It will just depend on how long it takes my jaw to not be numb as I am getting three back teeth pulled in the morning. I also need to try and see the engine machinist as the invoice for the heads has the part # for the valve springs as stock Crow and not the next one up as he said they were going to fit. Not overly bothered with stock springs but it does bother me they charged me nearly $240 for stockies when stiffer springs are $240 and stockies are about $130 which is what I believe I was quoted when I was asked about going stock or heavier.