Using magna injectors on pajero engine?

[disco stu]

Any reason why I wouldn't want to run the magna injectors on the Pajero engine? These injectors have half the km on them than the pajero ones, so I figure they would be in better condition

I know on first appearances you can't run them, I think I have things sussed out. The magna injectors are shorter than the pajero ones. This necessitates using the magna lower manifold, where the injector rail mounts are designed for that length.

But then.....the lower manifold is the wrong way around for the pajero upper manifold to go onto it in the right orientation. But, you can just turn it around and it lines/bolts up perfectly fine. This does leave a useless mounting position in the wrong end, and barbed end for the magna PCV valve at the back. But it appears that these are completely different between magna and pajero, so won't be used regardless.

I will miss out on some of the mounting positions on the pajero manifold though, but there is a stupid number of mounts for different things on those engines-everything is mounted to something else at least twice it seems. It will also miss out on the water jackets in the lower manifold of the pajero, but I really can't see the necessity of this.

I've thrown the pajero upper manifold on (with magna rocker covers etc though, other engine still in the pajero) and everything seems to have plenty of room.

Can anyone tell me a good reason why I would want to run the (old, tired, dirty, filthy actually) pajero injectors and/or the pajero lower manifold in this engine instead of the newer, shinier magna injectors?

Appreciate hearing any thoughts or comments on this, especially if you've done the magna engine swap thing and can give further thoughts on it.

Cheers

Stu

[brw0513]

Hi there disco-stu.

Please take your time in deciding on this one. The shinier Magna injectors won't be worth a pinch of pelican poop if you have a fueling issue (too rich, too lean, leaking seal because it got pinched on install).


During my 6G74 work I cleaned and re-kitted the OEM injectors. Overhaul kits are available from SCA for $22.99. There are heaps of injector cleaning videos on YouTube.

The fuel supply line on our engines is under considerable pressure and it wouldn't take much to ruin your day.

My 2c - do it right with the original injectors, overhaul kits and buy the three O-rings (one each side of the cross pipe and one at the regulator) to be sure.

[disco stu]

Cheers Ian. To be honest I don't think there will be much issue on the fueling side of things, both 4 hole injectors feeding the same engine. To be sure though I went off to find the specs on both injectors-wasn't that a painful exercise! Could work out the magna ones, they seem to be used in a fair few different engines. The pajero ones though seem to be unique to the pajero/montero, so I can't find the flow rate or resistance.

There is a slight difference in the shapes of the runners between the two. Pajero is pretty much perfectly round, the magna is an offset circle type deal. Putting the pajero top onto the magna bottom would mean there is not going to be a smooth transition between the two. That is starting to make me think a little more now. I'm wondering how tuned each is also

Part of me is very tempted to try to run the magna top manifold on the engine as well-I've heard that this is where the magna engine makes its extra power.

No one else has any thoughts or knowledge on this? From my previous searches and reading it seemed to be a very common question for those trying to do the 380/magna engine conversion

[stumagoo]

I just opened up a TH magna 3.5 in ecuflash the injector is scaled to 268cc where the pajero is 227 so there is very possibly a fueling issue possible buddy


Tep just opened several more the 3.0 uses a 220cc and the 3.5 a 268 (for magnas from 98 - 02)

With ecuflash we can deal with it but not sure if you have grabed a tactrix cable yet. But thanks because magna injectors may be the go for me in the future.- although I believe the 380 injector is a 312cc or similar.... I really need someone to confirm some of these figures though.

[disco stu]

Thanks Stu, that's a big help.

The figures you give for magna injector line up pretty much with the info I found-they are CDH275 and flow approx 275, and someone else mentioned seeing 268 in the ECU.

I haven't gotten a tactrix cable yet. I've pondered how doable my original idea is with spark maps and extra input to the ECU, and possibly found another solution with an aftermarket spark timing adjuster. If it was a cheap investment I would be happy to grab one to play around, but at $200+ I'm worried about blowing my money. One of the cheap Chinese ones is tempting at a much lower price, but I'm worried about bricking my ECU and like the idea of supporting those who worked all this out-just not sure I want to support them that much!
At the moment I've been struggling for energy and motivation, so I've held off looking further into rabbit holes and just trying to get other things finished off around here-too many ideas and not enough oomph to see them through!

I did read that someone said they compared the 380 and 3.5 magna injectors and they had the same flow rate, just that the 380 was 12 hole compared to magna 4 hole.

Really surprised they have such different flow rate, I would have put money down that they would be similarly rated. BRW was right, and I was wrong. That at least sorts out what I'm doing at the moment, and I'll go ahead and install these LPG injectors into the pajero manifold and clean out the pajero injectors. I'll put the magna stuff aside and possibly use that one day in the future if I have trouble with this. Tatrix cable is cheaper than a new set of injectors at least

Best solvent to clean out the injectors with? Carby cleaner, or straight acetone be alright?

Appreciate all the help

[stumagoo]

the cheap ones just wont connect with the software - I doubt they will brick the ecu as they wont get a connection to start with
as for the injector size we have a guy over here (perth) that is using 380 lower manifolds and injectors on his 6g75 conversions and I dont believe he is reflashing the ecu - I expect he is relying on the o2 sensor triming the fuel flow to make it work... I have not looked into his conversions so I cant answer that for certain

[brw0513]

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Best solvent to clean out the injectors with? Carby cleaner, or straight acetone be alright?
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I used carby cleaner and much like this:

https://www.youtube.com/watch?v=yTmrFyfEDZ8

I didn't do the "backwards" cleaning though.

[disco stu]

the cheap ones just wont connect with the software - I doubt they will brick the ecu as they wont get a connection to start with
as for the injector size we have a guy over here (perth) that is using 380 lower manifolds and injectors on his 6g75 conversions and I dont believe he is reflashing the ecu - I expect he is relying on the o2 sensor triming the fuel flow to make it work... I have not looked into his conversions so I cant answer that for certain

I've read that a lot of people who do the 3.8 conversion just use pajero injectors and rely on the ECU fuel trim to compensate. That's what was running through my mind with these magna injectors-i figured that the fuel trim would compensate for whatever difference in size was there. With such different sized injectors the injectors must be open for a much longer time on the pajero, and I figure it is pushing the fuel trim past what it is meant to do.

Reading some of the reviews, it seems that some people get the povo tactrix copies to work alright, but then you never know if they are just shills for the company making them. Plenty of people have trouble though. One thing I did read was that those who did get them to work had to use an old version of the software and couldn't be connected to the internet when they used the cable/software or something like that. I think I read also that it only liked intel processor computers. Part of me is tempted to try them just for intrigue......might do that later. I've got a TL magna ECU sitting here that I could use for testing things on. Maybe I'll whip the wiring harness out of that car to go with it before it gets taken

I used carby cleaner and much like this:

https://www.youtube.com/watch?v=yTmrFyfEDZ8

I didn't do the "backwards" cleaning though.

Makes it look pretty easy! That was pretty much exactly what I had in mind. Surprised how fast the spray pattern changed, I thought it would take a lot more time and work than that. Was that the same experience for you? Only problem is how much crap is all over the outside of my injectors-worried about cleaning them and that stuff going inside somehow. Wish I had cleaned them better before dismantling

[disco stu]

I take back what I said about 380 injectors flowing the same as the 3.5 magna injectors.

They're both high impedance types (13-16 ohms as I recall).

The CDH-275 injectors used for the 6G74 are valued at 268cc/min in the ECU code, and some googling turned up a reference to them being rated at 284cc/min (but no reference to fuel pressure for that rating).

That same reference suggests the CDH-305 injectors used in the 6G75 are rated at 308cc/min - ECU value unknown. These injectors have a different nozzle pattern (12 jet vs 4 jet for CDH-275).

I saw this by WytWun on aussie magna here: http://www.aussiemagna.com/forums/sh...ad.php?t=89121

[stumagoo]

I believe the part number is one of the references for ecu flow rates.... I know some magna tunes have 2 different size references - I believe one is just a notation for the part number or similar and the other is the scaling used for fueling - the scaling seems to be just smaller than the part number sizing - so pajero ones would be likely to be something like CDH-235 and the 6g75 ones would likely scale to around 290 but that is a guess.... if I was to install them I would be monitoring the fuel trims and the wideband that is going in in the near future.... but fuel trims will be just as important - I can run a number like 290 in the ecu and see what the fueling trims are adding/subtracting in the way of fuel if the number is an add of too much I reduce the ecu scaling for the injector.... Having fooled around with this already the injector can be quite a long way out (I have gone as fare as 240 on the stock 227 injectors) and it easily trims the fuel to suit. - I have also added an adjustable fuel reg to tweak the fueling as well... but that is yet to be p[layed with and is still running at 1-1

[disco stu]

So you haven't played with something in the order of 45cc out from injector to ECU scaling I'm guessing? Running 3.8 on 3.5l map is less than 10% increase, so I figure its easy for the trims to take care of that. Injector ~20% bigger would be outside what fuel trim can control I imagine, like you said.

It sounds like you just screwed around with the numbers there just to see if it would handle it-is that correct? That appeals to me, but trying to be pragmatic about things!

[stumagoo]

going from 227 to 240 pushed the trims from around -2ms or so to about + 6ms of squirt time with the trims maxing out at +/-16 ms I imagine that there is still headroom for another 20cc (around 260) in the ecu but without a wideband to confirm I would not risk it there is no need to do that normally. I was looking at upping the fuel pressure and increasing the injector size to compensate so I was not pushing duty cycles. However at stock scaling and 8psi I am not going over 65% according to the logging software

[disco stu]

Interesting, cheers

[disco stu]

I decided to contact denso to try and find out the actual flow rate. The official position of denso is that they don't give it that any specs on their products. Seems a bit stupid to me, as it's easily figured out by the competition, but it is what it is. So, the figures stumagoo pulled out of the ecu for injector flow are as close as we can get to official

[stumagoo]

what the actual numbers are is almost irrelevant, the reality is the ecu rates one at a number of 227 and the other at 268 which is an increase of nearly 20% - so the magna ones are between 15 and 20% larger