Dodgydiver

im building a 90 spec rs turbo and need some help please

1 on the fuel computer loom where does it plug in to the cars main wiring loom for power please

2 being the inlet manifold I have a black plug that looks the same as the plug on the water thermostat but black , where does this go please

3 the injection pump keeps running all the time with the ignition on , why does it do this and how to fix , thanks

4 any tips / tricks to get it started as I feel there has been no fuel through the metering head for years , there is fuel at the injectors but I don't know if there is enough
thanks so much for any help
darren

Dodgydiver

so I have sorted the fuel pump issue , the wrong relay has been installed

any help on the starting issue please

OAP Pete

From ex Auto sparks now retired at 76, completely up ON"Bosch K & KE system, The Injection loom does not "plug in" as you say to the main wiring harness, its incorporated with the main harness, which also goes to the 2 ECUs [ Silver & Black ]...with the exception of the Fuel Pump / cold start thermo Timer / 5th Injector / Fast idle control... this loom is totally hard wired and completely separate from the main harness and both ECUs, the "Black" plug you have goes to the Idle control Valve under the manifold......yellow will be "coolent sensor"....brown will be Thermo timer....Blue 5th injector....Green [ if later engine only] will be knock sensor. Fuel Test to start with [ as I feel you may well have "gummed" up metering unit and or all 4 injectors]...so....all 4 injector must be lifted out with there pipes connected...then bridge out 30 & 87 on relay plug...pump now runs, check at all injector Tips there is no Fuel seeping / not even any dampness of fuel as with this Test 35psi will or should be present at the injectors....pushing down the metering Flap slightly will cause the pressure to rise to 42psi approx. and fuel will spray. note these cars if the metering unit "Duff" due to bad old Fuel now gummed up, they will with good ignition system "Fire up" as the 5th injector will spray fuel directly into the manifold...hence it will burst into life on the Fuel in the manifold only....hence stop after a few seconds. so something to go on.....theres loads more. Peter

Dodgydiver

thanks so much Peter

the loom was referring to is a supplement loom that connects the fuel cmputer loom to the main cars loom

is there a way to check the 5th injector please

many thanks

OAP Pete

OK to test the 5th injector, first check the fuel supply is good, remove the fuel pipe from injector [ be carefull hear as there should be residule pressure left in the system as this line is on the main pressure line 85/90psi]...so some fuel will come out, place the pipe in a container..need 2 people really one to hold the pipe steady , then remove pump relay, bridge out 30 & 87..ie Red to Red/black tracer...you should see Fuel come out under very High pressure....if fine refit relay and fuel pipe, now to test the Electrical side, This test must be done on a stone cold engine...well we know yours is as does not run, but have to mention this.... unplug its blue plug, unplug the ignition coil by pulling off Black wire as we don't want any ignition to take place..... with a meter or Test lamp probe each wire..get someone to crank engine on starter...you should see cranking voltage , good battery 9 to 11 volt, for wire colure its Black/yellowtracer is the power + side...very unlikely this down as its on starter side [ known as circuit 50 ], the other wire Brown/white tracer comes from the Thermo timer..Brown plug...this is where it gets its negative...if the Timer is faulty then then unplug it and ground Brown/white wire re-test power should be there, this what ive wrote is for no power at injector plug....it seems to me there may not be...as if the metering unit..4 injectors all be blocked through Bad gunged petrol, yet the 5th injector sprays neat fuel into manifold...good spark...the engine must run, all be it for 2/3 seconds, I assume you have spark. once you know it runs can advise on the rest, but it may well be the metering head and 4 injectors blocked . Peter. just to add, never had a 5th injector faulty....so just apply 12volt poss & neg to terminals...you will hear it click.

Dodgydiver

where is the timer located please
thank you so much for the detailed explanation . ill have a play tomorrow

I think ill be pulling the injectors also to check them
thanks so much
darren

Dodgydiver

is there a fault finding sheet or similar

im unfamiliar with the bosh system so would like to run through a few things testing components as I go
is there like a flow chart thingy of things to check for a non starting car
thanks

OAP Pete

Thermo timer [Brown plug] under intake manifold....also water temp sender [Yellow plug]....also Auxillary air control [ Black plug]...all under manifold, also the Thermo timer also has 50 starter circuit at it, this allows only about 4 attemps to activate the 5th injector, it then cuts out needing around 4 mins to reset..... so as not to fill the manifold with Fuel, you see after the 5th injector fires the engine, the metering control takes over. Peter.

OAP Pete

I can explain how to test components , sensors etc, The 2 ECU do talk to each other, but the system is very much mechanical....if lead free petrol is left in system over many years of being off road, then the Fuel metering unit suffers bad as does the 4 injectors, the old petrol turns a Purple/Red gunge, and the Fuel tanks rust on the inside sending fine debre which does make its way through the filter, That's with a good fuel pump and a working 5th injector working, and 4 good sparks on cylinders, these car will start right up...but once petrol used up 3/4 seconds engine stops....that's when you know the injection system from metering unit not working...as said gunge up...I don't know hear history of car ?......normal working is 5th injector starts engine instantly...the pressure actuator would have received a signal from the Black ECU to increase the pressure in the system [ much like the old school "choke" ] so engine runs fine...the idle has been stepped up via the "Fast idle valve"...as the engine warms up the pressure actuator and the fast idle valve return to preset condition...via the "Bi-metal principle" so then perfect idle 850/900 and lower pressure to 4 injectors, the Thermo timer is also "Bi-metal principle"..ie shuts down completely the 5th injector, so warm / hot starts don't need it, of course if it ever came in would flood the hot engine, ive all readings on any sensor....feel myself be good to hear engine run..as said...petrol in the manifold..4 sparks..must fire...the Black ECU has no bearing on the separate wired Pump/relay or 5th injector / Thermo timer..there are some fuses in system..circuit 50 is not. Peter

Dodgydiver

@OAP Pete I have no power to the cold start injector
I have just replaced all fuel pipes so was only able to check yesterday
can you please advise me where to start diagnosing what is the cause of the fault please

many thanks for your time
darren

Dodgydiver

unknown plug
why can't I find where this goes . it comes from the bulkhead area , thanks

Dodgydiver

so I have got it started but its running so rich it hurts my eyes and runs very lumpy

once it has stopped running it won't re start unless I leave it for 5 mins again

timing is pretty close , no vac leaks that im aware of

thanks

OAP Pete

OK Circuit for 5th injector, first the Fuel supply is on the main pressure line, The 2 wires on the 5th injector [ Black/yellow tracer...&...Brown/white tracer ] Black/yellow is 12volt + ONLY when you crank the engine this circuit is known as circuit 50..... the Brown/white is negative - only when the engine is Cold.. this negative comes from the "Thermo timer" Brown plug...once the engine warms up the negative is switched off via its "wax" element..there for not needed in Hot starting, as a safety feature circuit 50 is at Thermo timer so if the engine does not start theres a contact in Timer that heats up and break the negative as well..this is know as the "Bi-metal principle", resets itself after several mins of non-cranking, this prevents the intake manifold filing with fuel and possible explosion, this entire circuit is a separate loom..non-fused, so hope of help. Peter.

Dodgydiver

that's a great help thanks

it seems to be working then , sounds like I have another issue to try to figure out then

OAP Pete

Leaking injectors 4......5th injector leaking...Co far to High...not common on 5th...but yes on all 4 injectors if car been off road for some time, Lead free petrol turns bad causing the valve in injector to not seat properly....pressure actuator has contant voltage at it...this will cause bad over fueling. Peter

Dodgydiver

injectors have had new "o" rings fitted and new fuel hoses as 1 was leaking
thanks

OAP Pete

Test for leaking injectors, all 4 injectors have to lifted out with there pipes on, .....wipe clean there ends, bridge Fuel pump relay 30../ ..87..pump runs...carefull look at each injector for any Dripping as you will have 35psi at them..they must remain Dry,

Dodgydiver

ok ill test that tomorrow , thank you

Dodgydiver

just puled the plugs and they are all black and sooty , ordered a new set for Monday and new ignition leads also

iansoutham

you are performing a temporary fix to a symptom of the starting issue, not actually addressing the actual problem. This means the problem will return almost immediately.

listen to the advice above and follow it.

Dodgydiver

I am waiting for a new inlet manifold gasket as I think I have a vac leak . im aware the plugs and leads are not the cause of the issue but they still need replacing anyway .I have to remove the injectors to test so ill change the gasket at the same time

Dodgydiver

I have acquired man flu , ill get back to this at the weekend if I manage to make it through the week

Dodgydiver

@OAP Pete sorry its took a while to come back to you

when the fuel pump is running with the relay bridges there is no fuel dripping from any of the injectors
the moment I touch the flap by the metering head then the thing makes a squealing noise and fuel comes out in a spray from every injector
I have a new gasket fitted on the inlet and the sandwich plate , I have also replaced plugs . leads . cap and rotor arm as these where of unknown condition
there was always a good clean spark but wanted to change them any way

would you mind advising where to move forward please
I have left the vacuum to the ecu but all others have been blanked to ensure I don't have a leak
thanks

mk2grp1

have you tried the co adjustment screw ?

Dodgydiver

@mk2grp1 no as im unsure how to adjust as I have no gas analyser

mk2grp1

anti clockwise to decrease co if adjuster has an ally spout its easy, half a turn may do

Dodgydiver

yeah it has the spout
is there a measurement on the flap I can work with
other wise its just a guess

mk2grp1

co far too high your not fine tuning it just lowering the petrol heavy exhaust gases half a turn is not critical, your getting it up and running again not getting ready for a drag race,
a co machine is far from where you are, but would be nice

OAP Pete

as above the Co mat be far too High, need analyser to check, but as stated Half a turn with a long "alan key" anti-clock, once it running and gets Hot you can play with the Co adjuster...again anti-clock...very small movements of adjustment you should hear the engine respond to a weaker mixture run faster / smother....at least then able to get it set a garage to check / adjust 1.3 to 2.0 ideal, the other item to give over fueling, leaking 5th injector, easy check remove with pipe still on, bridge 30 / 87 pump runs all time, now with 85/90 psi at that injector, so check on leaking , rare for these ever to give problem back in day...but must check, also worth checking the pressure actuator , thats the 2 pin plug on the front of the metering unit, use meter on Ohms, you should see 16 to 21 0hms across the pins...if no reading, it means 12v in the past has been applied to it for a period and burnt out the "Bi-metal element" and the pressure cannot return to normal running, seen it back in the day..but rare..you see this unit adjusts the fuel pressure for starting Cold only..rather a delicate unit...seeing only voltages of 2v to 9v tops and that at a pre-determind time of seconds only, cooling itself re - the Bi-metal princible.. just to let you know, hope yours ok. Peter.

mk2grp1

Nice of you to share your knowledge Pete mine sat for 5 or so years and after king lead off prime, it ran for approx 5 minutes with Ł20 of fresh fuel, and after 5 the fuel pump gummed up,
thats where i am , another 5 years on , need to jack it up 1day

Dodgydiver

thanks for all the help guy s


ITS RUNNING , the mixture screw was to the max , so would it out loads and it ran tweaked it to where it sounds the best but I think its still to rich
its kinda a little smokey I think , but that's good enough for now so I can carry on with other jobs

odd thing is that there counter reads double what the engine is doing
any ideas ??

OAP Pete

Great, you can later get the Co set to 1.5 / 2.0, rev counter a strang one...its connected in the loom to the Green on the coil negative, then direct to Dashbourd, , check Earth on Dash itself...Brown is earth, the circuit again appears at Fuel pump relay, but a change of colure there to Green/Red tracer, just in case there is something in the relay upsetting the pulse ?...you can allways remove relay...bridge out 30 / 87...start engine..is it the same ?.. Your note the engine should start easy now on the 5th injector...have decent fast idle..while warming up due to the idle control and pressure actuator..as you say far..far too much pressure with the Co right in. Peter

mk2grp1

yeah they be xr3i efi clocks they were run from coil pack ignition you need mfi clocks, or just revo swap