EFI question on 3.9V8

[Tobias]

I've put a 3.9L (from aquarangie) in my 88rr a while ago, but im still running on the 3.5L EFI(flapper) injection system. I have the 3.9 EFI injection gear but haven't been able to get it going and don't have the time to at the moment. The engine runs great and i get about 14L/100km on a good highway run. My question is should i make the effort to put the 3.9 manifold and injection gear back on?
I realise i'm probably don't have as much power as i should becuase im using the old gear but i still notice a big gain over the old engine. Am i causing damage to the engine by running it using Flapper injection?

Thanks,

Toby.

[Philip A]

Well, just do not run at full throttle high revs at it would be lean and you could burn a piston or valve.as the injectors are smaller than 3.9 and the flapper would probably max out early.

But under normal cruising etc OK, but watch those big hills high load.
regards Philip A

[fridgefreezer]

Beg to differ - the injectors are the same from 3.5 to 4.6.

Also one of the few advantages of Rover's mass-airflow system is that it will adjust to the larger engine size without too much drama. If it has Lambda sensors you're even better off as it will "learn" and hopefully sort itself out.

Worth keeping an eye on things in case (shock horror) it doesn't work properly, but it *should* get along OK.

Blimey - Lucas EFi has a good point, who'd have thought it?

For more info google "MAF Vs MAP sensed EFi" or similar.

[RaginRover]

Beg to differ - the injectors are the same from 3.5 to 4.6.

Also one of the few advantages of Rover's mass-airflow system is that it will adjust to the larger engine size without too much drama. If it has Lambda sensors you're even better off as it will "learn" and hopefully sort itself out.

Worth keeping an eye on things in case (shock horror) it doesn't work properly, but it *should* get along OK.

Blimey - Lucas EFi has a good point, who'd have thought it?

For more info google "MAF Vs MAP sensed EFi" or similar.

Fridge,

All the rangies up to and including the P38 weren't fitted with Lambda sensors when they shipped to Australia.

I have always wanted to retro fit one in each bank and wire it up to the ecu to see if that would improve "ecomomy"

Tom

[Philip A]

Beg to beg to differ/

The 3.5 flappers have completely different injectors with a hose on top rather than slotting into a socket with an O ring. 3.5 in Disco probably has later injectors but it also has a MAF. while the 3.5 I had was an early "Federal" injection which i fitted to a 77 I am sure the 3.5 Rangies had the same rail.

Just this morning I saw a Disco rail that a guy had to buy to fit a Haltech to his 3.5 which he had replaced by 3.9 as the 3.5 injectors were too small and he wanted to fit readily obtainable Holden injectors.

Boy have I researched this topic, as I have now successfully fitted a Thor manifold to my 3.9 , but used my old 3.9 rail, and bought NEW Bosch 22 Lb 4 hole "pink" injectors from USA at AUD 55 each. AND I am running it with my 14CUX and a Unichip. Go to the dyno tomorrow to trim the fuel values.Yeehaaa!!!!
I Stand by my original post
Regard s Philip A

[RaginRover]

Beg to beg to differ/

The 3.5 flappers have completely different injectors with a hose on top rather than slotting into a socket with an O ring. 3.5 in Disco probably has later injectors but it also has a MAF. while the 3.5 I had was an early "Federal" injection which i fitted to a 77 I am sure the 3.5 Rangies had the same rail.

Just this morning I saw a Disco rail that a guy had to buy to fit a Haltech to his 3.5 which he had replaced by 3.9 as the 3.5 injectors were too small and he wanted to fit readily obtainable Holden injectors.

Boy have I researched this topic, as I have now successfully fitted a Thor manifold to my 3.9 , but used my old 3.9 rail, and bought NEW Bosch 22 Lb 4 hole "pink" injectors from USA at AUD 55 each. AND I am running it with my 14CUX and a Unichip. Go to the dyno tomorrow to trim the fuel values.Yeehaaa!!!!
I Stand by my original post
Regard s Philip A

Keen to see how you go on the Dyno

Tom

[Philip A]

Thanks Tom, she has subjectively another 10-15% torque up to 3000RPM but is running lean on the new injectors so maybe more to come.
It is GREAT!!!

Toby,
i would try to get her to run on teh 14CUX 3.9 as the Hitachi MAFs generally do not die young.
However the 14 CUX has a speed input from the 89 onward electronic speedo, so you would have to somehow rig up a speed sensor to tell it its moving. I do not know exactly what the sensor does. I do know it speeds the idle as soon as you are moving fro a smoother change down when coming to a stop. Also it give override fuel shutoff. Wwhether it does othe rthings I do not know.
Reagrd s Philip A

[fridgefreezer]

Forgot about the Aussie difference - and yes the early ones have the nasty hose barb connectors. Still not convinced you need to upgrade them on a stock engine and MAF sensed system, I have been running early 3.5 injectors on the 3.9 for ages with no trouble, although admittedly I have a proper* ECU

* = Not Lucarse

[Philip A]

Fridgefreezer , how do you go with the Megasquirt in low ratio first just trickling/idling , and hitting the brakes. Apparently surge is common with MAF only units in this situation, and I have seen it with Motec on a club members car. The guy was driven mad by the car speeding up at obstacles. I theorise that it is caused by the ECU thinking the loss in vacuum caused by the brakes is an opening of the throttle and increasing injector bandwidth.

I will be really interested when the guys bring out the version with IACV capability in a mature way, and broad band EGO.

Regards Philip A

[fridgefreezer]

Fridgefreezer , how do you go with the Megasquirt in low ratio first just trickling/idling , and hitting the brakes. Apparently surge is common with MAF only units in this situation, and I have seen it with Motec on a club members car. The guy was driven mad by the car speeding up at obstacles. I theorise that it is caused by the ECU thinking the loss in vacuum caused by the brakes is an opening of the throttle and increasing injector bandwidth.

I will be really interested when the guys bring out the version with IACV capability in a mature way, and broad band EGO.

Regards Philip A

Phil - I think you answered your own question there, it must be a MAF-only thing. Never had a problem with the MS off-road. In fact the only problems I've had or seen with MS have been my crap soldering of wires onto the plug, and my inability to tune an engine

Just how mature do you want IACV control? It's there already, I believe everything from a single extra air solenoid, through twin solenoids, Ford PWM controlled ones to stepper motors have now been implemented.

Broadband EGO has been done ages ago, I think currently the code will support dual wideband Lambda sensors with independant bank-tuning being mentioned (can't remember if it's been implemented yet or not) so it can tweak each bank individually. I'm a bit out of touch with current development 'cos the trucks off the road. I know there are some V3 boards floating round which add a lot of Neat Stuff (TM), I'm quite keen to get my hands on one to play with.

[Philip A]

I meant MAP MAP damn it!!!

[fridgefreezer]

OK, you meant MAP, but I've still never had a problem