v8 EFI install couple of questions

[iomlt]

hello,

I'm installing a 3.9 efi into a 1985 V8 90. I used the engine and ecu loom out of a 1992 rrc. its all plumbed in i'm using a external fuel pump and i know this works as i used it in the range rover prior to puttin in a diesel.

so the 90 Problem i'm having is she turning over the fuel pump relay (efi loom) is clicking making fuel pump for 3 seconds or so, relay kicks off and i can here the stepper motor idle valve do its thing i turn over, engine turns over nicely but no v8 noise.i'm getting a good spark. I'm 99% sure its down to electrics that control the fueling as the plugs are staying dry.

the way i have wired the efi up is as follows

Green/Orange, Permanent battery feed to ECU, often shown as brown(N), ECU pin15, used

White/Purple, From fuel pump relay, to inertia switch, used

Brown/Orange, efi light on dash i think, Not used

Black/Yellow, to MIL lamp, not used

White/Grey, from ignition switch, Used. Shown as white/slate.

Orange/Black, from neutral switch, not used

Purple/Yellow, from heated front screen relay, not use

Yellow, from speed sensor, not used

Any help would be apreciated as i though i had cracked it but now struggling.

[patch1]

Hi. Is the White/Black pickup wire conected to the ignition coil negative terminal and is the resister pluged in on this wire aswell.

This wire comes out of the loom by the connector for the air flow meter (AMF)

It sounds like the ECU dosen't know the engine is turning over.

Hope this helps

Mark

[iomlt]

thanks for the very quick reply,

yes all connected. i will recheck but i'm 99% sure they are. next?

[mad_pete]

I had a problem with mine that the ecu feed wasn't live on cranking.

[mad_pete]

The fuel pump primes for a few seconds and then goes quiet that's normal and the ECU needs to see the fuel pump go live but I think you have that covered.

[ThreeSheds]

Wire the fuel pump into a permanent feed and see if it starts then.

If it does - then back to ECU and why it's not telling the pump to run while cranking.

If it doesn't then you are into checking fuel supply to injectors, fuel pressure, and injector wiring I guess...

HTH

Roger

[iomlt]

been out for a quick look play. i'm getting constant power when cracking, no loss on either the ignition or constant supply when cracking. wires are in the correct place to coil etc. plugs dry. so defo fueling or ecu not telling injects to do their thing.

i have tried constant powering the fuel pump still nothing and still dry plugs.

as per first post about wiring, i'm only using 3 wires, constant 12 to ecu, ignition to ecu and the fuel pump wire, am i correct there? i just get a funny feeling maybe i'm missing something there?

[ThreeSheds]

I can't see where the injectors are wired in the above post - have I missed something?

[patch1]

I think he is on about the wires in the connector that connects the engine EFI loom to the rest of the vehicle, the injector conections are internal to this loom.

Are the EFI looms negative connection ok?

Mark

[iomlt]

I can't see where the injectors are wired in the above post - have I missed something?

yep i'm on about the main plug that connects into the vehicle loom.

If there is one negative connector situated front right of the original vehicle then yes i have earthed it. i'm unable to find any other earths through out the loom. Only little bit of info i left out as i feel it has no relivence is next to the vehicle plug of the efi wiring there is another small connector, 4 wires but i'm 90% these are not needed wire colours white /green. black / red. black / slate. yellow / red.

my new questions / check points. only 1 negative correct?

this other connector next to the main vehicle connector not needed?

only last thing i can think of is to ask one of you guys nicely to take photos of how you have connected the main plug, wiring of the coil, other than those two i carnt think of anything else being incorrect. as the efi loom has not been tampered with.

last thing is i know for a fact this all ran together this time last week in the rrc as i had it started and running for a while. then i transfered it over this weekend gone.

[patch1]

Its for connecting the fault code reader too.

[iomlt]

Its for connecting the fault code reader too.

is my best plan to get it plugged in? I'm alittle baffeled into why she wont go.... the efi system as a bundle is relitively simple (eating my words now thou) only half a dozen wires that you have to deal with the rest there is no need to touch it....

thank you for all your replies its nice to have a check list to check over.

[patch1]

Found this on my PC.

Might be of use if I can upload it properly.

Mark

[iomlt]

i have been using wiring diagram to try and problem solve.

looking at this diagram number 12 is the plug we're talking about as to vehicle loom connection - the diagram show's only 7 connections i have 8.

Can we confirm i'm correct with my wiring below ?

Green/Orange, Permanent battery feed to ECU, often shown as brown(N), ECU pin15, required.

White/Purple, From fuel pump relay, to inertia switch, required.

Brown/Orange, no idea, probably for Fault Display, not required.

Black/Yellow, to MIL lamp, not required.

White/Grey, from ignition switch, required. Shown as white/slate. Pin 19

Orange/Black, from neutral switch, not required.

Purple/Yellow, from heated front screen relay, not required.

Yellow, from speed sensor, lack of speed sensor pulses can cause problems with idle function

[patch1]

From what you have listed seems ok to me and the connection between the coil neg and pin 39 of the ECU or reading the correct resistance of 6.8K ohm is ok, then it should run.

Are both of the relays (Main and Fuel) ok. Are they the original ones or of the correct type. The main relay is used to turn all of the sensors ond the injectors on.

[iomlt]

From what you have listed seems ok to me and the connection between the coil neg and pin 39 of the ECU or reading the correct resistance of 6.8K ohm is ok, then it should run.

Are both of the relays (Main and Fuel) ok. Are they the original ones or of the correct type. The main relay is used to turn all of the sensors ond the injectors on.

i have swopped over the two relays as they are the same and orignal. i will measure the reading and report back tomorrow. Thank you for your help so far, i'll take some pic's and hopefully you will spot something frightfully simple! (finger crossed)

regards

al

[iomlt]

gone out and checked a few things and taken a couple of pics.

tried turning over with fuel pump on constant no change.

there is one connector (black one in Pic) near the main vehicle loom plug (white plug) that i'm alittle concerned about. i dont think its the dianostic plug as isnt that near the relays and ecu connector? see pics.

I havent checked the resitance to pin 39 yet. and i wont till i return next week (holiday).

here are a couple of pics

any other thoughts?

oh i did check that both relays are working and both seem to be clicking again i havent had chance to take readings but i will on my return.

[pitmole]

Hi there, just a little note, you have got the fuel and return hoses on the right way round i hope?

[patch1]

The white connector by the relays is the diagnostic one. I would say that the black one by the vehicle one is the aircon connector as I see the green aircon relay is installed, don't know what the fuses are for mine hasn't got them.

Mark

[iomlt]

Hi there, just a little note, you have got the fuel and return hoses on the right way round i hope?

just to confirm that the fuel in is not directly into the regulator? the pipe from the pressure regulator is the return?so the fuel goes round the passenger bank round the drivers then exits ?

The white connector by the relays is the diagnostic one. I would say that the black one by the vehicle one is the aircon connector as I see the green aircon relay is installed, don't know what the fuses are for mine hasn't got them.

Mark

i can easily check that, once i get back from my jollies from the uk. I know one of the fuses is for the fuel pump relay.

but once again thank you for the replys.

al

[iomlt]

update for you,

shes alive.... rechecked most connections etc. still nothing. i then disconnected the white plud with the single loop wire on it i believe this is the diagnostic plug, then pluged it back together and she fired up! :S explain that? looking at the second picture its the far far right one (white).

jsut a big thankyou to everyone that helped me with suggestions etc.

a handy piece of info i found was this.

"Initial start up sequence.

The sequence to restart the engine actually starts as you turn off

the ignition switch. As the ignition voltage is removed from the ECU,

the unit sends out a signal to the stepper motor attached to the

plenum chamber to wind it fully backwards and allow maximum air into

the plenum chamber. This can be heard as a buzz from the stepper motor

as the engine dies. As the ignition voltage has now gone, the engine

simply stops with the stepper motor in maximum air position.

On turning the ignition back on, a short pulse (about 1- 3 seconds)

is sent to the fuel pump to pressurise the fuel rail. Once the starter

motor starts to turn the engine, a 12v pulse is fed back to the ECU

from the negative side of the coil as it the ignition amplifier

switches. The ECU then turns on the fuel pump and energises the fuel

relay that provides a fixed 12 volt supply to all the injectors. The

transistors in the ECU starts to ground the injectors with a longer

pulse than the normal idle pulse for about 3 seconds. This provides

enough fuel to start the engine, combined with the stepper motor still

being in its wide open position. Once the engine has fired, the air

flow meter then takes over feeding the air flow volume back signal to

the ECU and the injector pulse width is reduced to match the fuelling

requirements for the engine at tick over. The stepper motor is also

wound in to stabilise the idle at around 800 RPM. This system accounts

for the short burst of higher RPM at tick over as the stepper goes

from wide open to part closed during the start process.

One side effect of this system is if air leak develops any where in

the inlet system, the engine will start and run for 3-4 seconds and

then die. The initial over rich mixture will allow the engine to run,

but once the air flow volume comes into play, (Now reduced because of

the air leak) the injector pulse width is reduced to the point where

the is insufficient fuel to keep the engine running, so it dies. The

whole pipe work and breather system around the plenum chamber is

pretty finely balanced and can be easily go out of tolerance should an

air leak develop."

[patch1]

Hi Al,

Glad shes up and running and hope thats the end of the problems and you can get out and drive it. My 90V8 is still just an engine in a rolling chassis and its been like that for 12 months due to job losses and becoming self employed.

Mark

[iomlt]

Hi Al,

Glad shes up and running and hope thats the end of the problems and you can get out and drive it. My 90V8 is still just an engine in a rolling chassis and its been like that for 12 months due to job losses and becoming self employed.

Mark

Cheers Mark,

I have a little way to go yet. replaced steering box, linkage and between a tdi and rrc V8 steering hoses made it as factory looking as possible. Fuel pump and filter fitted and tidy under the seat box up out of harms way. Lots of attention to detail with earthing, as a galvanised chassis isnt the nicest to earth. like wise with the bulk head, retappedin threads and earths. New sumo bars with ome damper. Oh plumbing in the water hoses to rad and installing a later header tank so again making hoses and Rivnutting brackets etc. Decided to us a TD radiator as it has the oil cooler part as my 3.9 has engine oil cooler pipes. Exhaust is on janspeed headers and Y piece and stainless middle, silencer and tail pipe fitted.

tomorrows job is to replace heater with a later type oh and connect hoses up, then want to mount the ecu and relays tidily behide the drivers seat on the bulk head and put in a new fuse box for the feeds for the ecu etc. fill with water and run till hot, check or leaks and then if all ok replace with coolent.

quick question again / advice please, i have a tornado chipped ecu, i'm havent ran it yet with the engine as i wanted to make sure she worked before installing. with this being a relatively standard motor bar exhaust and induction is it worth installing still? they say fueling is slightly different and is a must.... what are your thoughts? (my engine has done less that 47k)

[patch1]

I would have thort its got to help but more power has got to mean more fuel, hasn't it?

I had my engine running for about 30sec on the workshop floor must be two years ago so your still further along than I am, but like you am trying for the factory fit and tidy look; things like proper fitting hoses and as I used to work for and design wiring looms so I shall make a custem one.

[iomlt]

I thought the same. A few friends have td5 that are chipepd and they swear to him upstairs that they use less fuel as they dont have to hit the loud peddle so hard going up and down hills ant the likes.....

I think i'll through it in and seen what happens..... lol (famous last words)

I'm with you 100% trying to make things look as factory as possible..... so much easier to work and to look at. So far the biggest expense have been replacement doors. i was going to through series doors on but really want this vechicle to be a nice clean tidy daily car so managed to located (from this forum) a pair or orignal 1985 doors that have been dry stored for 20 years and my god there MINT!

Mark what are you doing interior wise? they dont make any carpet sets for a santana 5 speed (orignal V8 tunnel etc) i think my only option is to have a custom build..... I would ideally love to have that 1 piece matting but again they dont make it for the V8.

AL