curly

iTrader: (25)

Just finished wiring up a 94 with a '01+ engine harness for cleanness, and plugged in a pnp adapter harness and Hydra 2.7.

Coils according to the first post in this thread were backwards. You can't change the Hydra coil outputs within the software, they have to be wired correctly. Before I dig into the adapter harness to see if it's the issue, has anyone else experienced this? I have brown to brown/white, and brown/yellow to black/yellow.

Also, I went through all the work to install a TSE oil pressure adapter, SS line, and cut/drilled/tapped the upper hard line for a AN-NPT adapter, since I'm putting a VVT head on a 94 block. Did I do all that work for nothing? Am I reading in post #281 that I didn't have to do all that?

aidandj

iTrader: (5)

AFAIK you just use the stock VVT hardline, and it bolts up to the VVT block. The blocks are basically identical. But with different threading.

aidandj

iTrader: (5)

Also you can't change the coil outputs in megasquirt either.

curly

iTrader: (25)

Right, so the vvt banjo bolt doesn't just thread into the 94's tapered oil pressure sensor's threads does it?

The firing order I'm thinking of must be injection timing then.

aidandj

iTrader: (5)

Maybe not stock. But it should be very simple to tap it to straight threads. It also might be close enough to just thread in.

fredb

iTrader: (1)

Not sure about the coil wiring but the VVT plumbing works just fine ,no modifications for my swap. I too used a 94 block with a VVT head. No leaks VVT works fine.

aidandj

iTrader: (5)

NICE. Thats what I wanted to happen. Did you retap the hole or anything?

fredb

iTrader: (1)

No modifications , just screwed it all together using the factory parts. Fred

aidandj

iTrader: (5)

Curly, can you add that info to the first post of this thread? For future readers.

shuiend

iTrader: (24)

I can also confirm that the stock vvt oil hard-line will bolt onto a 94 block fine. If you are using stock coils with the stock bracket then you cNnot use the hard-line.

aidandj

iTrader: (5)

Stock 94 coils right?

I see you haven't floated away yet.

shuiend

iTrader: (24)

Yeah stock 94 coils.

Nope did not float away. Lots of rain and wind. Other then that we are fine.

Savington

iTrader: (31)

Check your adapter harness. Uncle Humjaba confirmed his '95 wiring to be the opposite of what you have in post #160. It would also be highly illogical for Mazda to use brown/yellow as the trigger for coil 1/4 in 1990-1993 (verified in #156), then use brown/yellow as the trigger for coil 2/3 in 1994-1995.

GraemeD

iTrader: (1)

I did tap the hole, from tapered thread to straight thread. No problems this way.

But, as an additional data point,
when the '94 oil pressure sender was in the '01 location in the hard line, I noticed oil pressure fluctuations when changing throttle settings. I corolated them to the vvt changing. So I plugged the oem sensor location, welded a AN3 nipple to the end of the banjo bolt, so the sensor would read the pressure in the oil galley and not the hard line. Ran a ss line to the same sensor mounted on the inner fender well. Now rock solid oil pressure indication at any throttle angle. Moral of the story is there is a slight restriction when the oil turns and goes thru the holes in the banjo bolt, enough to cause a slight drop in pressure that can be seen on the oil pressure gauge.

aidandj

iTrader: (5)

You essentially created a pulse damper with that AN3 line. So the pulses might be at the galley too. Wouldn't be able to tell without putting the sensor there.

hi_im_sean

iTrader: (3)

Your mom is a pulse damper.

GraemeD

iTrader: (1)

Oil is a liquid, and there for non-compressible, so a properly bled line and sensor will transmit every little pressure change. But your mileage may vary.

aidandj

iTrader: (5)

But a line might not be incompressible. Fuel is non-compressible, and yet we still have pulse dampers on fuel rails.

GraemeD

iTrader: (1)

True, a line might be compliant, but with only 40-60 psi, a stainless braided Teflon line won't absorb the pressure fluctuations. The fluctuations are not pulsation, it is a momentary drop/rise when the vvt valve opens/closes.
A FPD is another animal, used for damping pulses from the injectors opening and closing, a decent description is found HERE.

I was was just stating a problem that I saw and what I did to cure it, take it for what it's worth.

aidandj

iTrader: (5)

Cool good to know. Not arguing here. Just thinking out loud.

Wonder if you can find one of these with the right threads.