stevealien

iTrader: (1)

Heyguys
I'm at my unit working on car.
Not run it for couple weeks.
Started it and it runs like a bag of poo and won't rev.
If I remove heated seat fuse it runs perfect.
Or if I remove plug to black box on right side of metering unit ( fuel flow valve thingy) it also runs perfect.
Any ideas fellas ?
I've tried a new black box fuel flow valve and still the same.
If I unplug fuel ecu it runs fine.
Tried a spare fuel ecu and still same.
I'm kinda stumped.
Anyone save the day ?
Cheers guys

stevealien

iTrader: (1)

Anyone help please???

martinmilne

heated seat ? dont know about that but maybe a sensor has packed up

stevealien

iTrader: (1)

The heated seat fuse has something to do with fuelling iirc.

Here's what's happening.
Everything connected car runs terrible and I can't rev it. Sounds like running on 2 cyl lol.

This is what I tried.
Unplugged black box on right of mfi unit ( electronic fuel valve ).
With it unplugged , car instantly revs up and runs fine.
Plug it back in and it stalls.
Replaced black box with a known working spare and still same prob.

Ok
so I then plugged electronic fuel valve back in and removed heated seat fuse.
With fuse out car runs perfect.
Soon as I put fuse back in it dies.

Ok
so then I reconnected everything and unplugged black fuel ecu.
Car runs perfect with it unplugged.
Swapped fuel ecu for known working spare. Problem still there.

So basically I have to either unplug the fuel ecu , the electronic fuel valve on mfi unit or remove heated seat fuse to get the car to Start.

I'm sure this all points to something simple but I don't know what lol.

Can anybody diagnose please ?
Thanks guys

teahan

the fuse is for the fuel ecu i'm pretty sure, are you sure the second fuel ecu is good? without that ecu connected the car is behaving like an mfi xr3i, it'll underfuel and destroy itself when its comes on boost. check up the technical articles by stu, might help.

Adamkelly

the egsact same thing was hapeing to my S1 last week,
turned out to be a nackerd water temp sensor.

To test unplug it, and short out the to conections, if it run its buggerd,
get a new one..


Ak

stevealien

iTrader: (1)

Where is water pump sensor mate ?
Do you mean the White plugged one that is the inlet manifold and shares the bracket with the air aux valve. ?

Versus_Creations

iTrader: (1)

Need a new sensor on the metering unit going by what you have said.,

stevealien

iTrader: (1)

hi Jano
which sensor do you mean bud ?
I've swapped the black fuel valve on the right side of meter unit and still same prob.
Not touched the left side black box yet. Is that a airflow sensor ?
Was dubious about removing that as it's got black mastik covering all the screw holes and wasn't sure what would happen if I undid it

Adamkelly

That is the air flow sensor on left side of meter unit, not much to go wrong there really.

the water temp sensor is under the inlet mani,
just below the blue cold start valve.

stevealien

iTrader: (1)

Been messing around withcar all evening and can't get it to run without either unplugging heated seat fuse , fuel ecu, or fuel control valve on metering unit.

Tried unplugging sensors and makes no difference.
How do I test thermotime sensors and water temp sensors ?
Can I just bridge the plug with a piece of wire ?
Surely they have to recieve a signal of a certain resistance ?

Doing my head in this is. I've got a new bald patch tonight.
Bastard car

luxembourgrst

hy i have exactly the same problem like you after a engine rebuild when i unpluged the black box (who is fixed with 2 srew on the metering unit) on the side my car runs normal and when i plug it back in the engine works bad and when i pusch on the gaz pedal there is no response
then i unpluged it again and runs directly good again
i cheked and i always have 8.20 VOLT on this plug

with this i have a very lought fuel pump that i gone change maybe it is the fuel pump my is very very lought

on s2 1988 (under the intel manifold)
i have a yellow blug i switchet with a wire and nothing change i also switched the brown plug no change

stevealien

iTrader: (1)

Yeah mines same. 8 volts to one side of fuel flow valve and nothing to other side.
Yellow thermotime swith has 5v to one side of plug and nothing to otherside.

Seems we have the same fault.
Please please let me know if you find out what's wrong and I'll let you know if I find out mate

martysmartie

iTrader: (1)

The fuse marked as heated seats is actually for the Fuel ECU, as said above it's extremely important as without the "Black box of tricks" it cannot see any positive pressure and so won't fuel for it, I.E as said it's effectivly running a N/A setup like in a XR3I.

Martin

stevealien

iTrader: (1)

any ideas whats wrong then?

luxembourgrst

well i gone a change my fuel pump soon and tell you what hepend

martysmartie

iTrader: (1)

I have never owned an Escort or an MFI car for that matter so I don't really know enough about the MFI system to comment but it sounds like something else assuming both your Fuel ECU'S are known to be good, clearly they are doing something by the fact it changes when they are unplugged, is there not a chip inside that would have needed changing when you tried the other Fuel ECU or is that in the other ECU? I know the Fuel ECU provides all the post starting and cold start enrichment as well as on boost fuelling, maybe check all the connections to it?

Martin

stevealien

iTrader: (1)

Checked all connections and everything I can think of.
If it was the airflow sensor on metering unit would that be these symptoms ?
And does anyone know how I can test my water temp sensors and thermotime sensors and wether or not I can bridge them with wire to test ?

JesseT

You should unplug the black fuel ecu from its connector, and using a multimeter, check from the correct pins the water temp sensor, the air flow meter, and the WOT switch. These will generate electric fuelling corrections. Some of these seem to be faulty. If you unplug the fuse, ecu or the small black box connector on the side of the metering head, you will disable all possible fuelling corrections. In this case the car will fuel entirely based on the position of the airflowmeter's disc. No cold start enrichments, no acceleration enrichments, no decelaration fuel cut, etc... At normal stady condition with a warm engine, there shold be no correction to either way, and so the removing of the fuse should not effect.

Get yourself the S1 workshop manual. It has all the needed information and diagrams for the RST's management, and what to measure from which pin.

The black fuel ecu and fuelling in general will never know anything about the boost pressure and will not correct for it.

Rob_DOHC

iTrader: (4)

With a warm engine, unplugging the 'black box' (which is an electronic fuel pressure reg) will make the metering unit fuel with out input from ecu.

2 potential areas to check,

1) The 'black box is fucked' but you have tried two.

or

2) It is receiving a duff input from the ecu,

This is why the fuse effects the car in the same way as unplugging the black box.

The ECU has a number of inputs, the important two being, coolant temperature and air temperature. Check/replace these two, and let us know if/what it changes. A third check (as stated above) is the tps, but im not sure it will effect the tick over this drastically....

The third option is of course a fucked fuel ecu.

Rob,

Rob_DOHC

iTrader: (4)

Fuck the thermo time switch for the sec, that only controls the cold start injector AFAIK. Concentrate on eliminating the ECU inputs which have a direct influence over the black box and hence vehicle fueling.

Rob_DOHC

iTrader: (4)

The metering unit has one sensor, it could be this i guess, but i doubt it.

Rob,

luxembourgrst

you are speaking about the bosch ECU?

we have always 8.20 volt on plug who goes on the black box on the metering unit
when the engine is hot

Rob_DOHC

iTrader: (4)

Yes,

Your ecu, is outputting this voltage. You must now find out why.

One plausible reason is a faulty sensor, the two most common are coolant or air temp. Have you checked these?

Rob,

stevealien

iTrader: (1)

well guys ive solved it.

i removed the wiper mechanism to paint it last week and removed the 2 earth wires that go to the wiper motor bracket.

i didnt realise this was a earth for the fuel ecu (thanks to power engineering today),.
as i had painted the wiper motor bracket,i ran a earth from the battery to the 2 brown wires that went to wiper motor bracket and hey presto its fixed.
what a result cos i was worried it would be a mare to find the fault.

spoke to ian at power enginerring today,and he was such a helpfull bloke.
very nice on the phone,went through loads of things with me,and happen to menton the earths on wiper motor being fuel ecu earth.

he also said that it could have been the water temp sensor ( the yellow one underneath inlet mani),and he said that to test it,its ok to bridge the plug with a paperclip,if it works,then sensor is fooked.

so,im a happy man again today.

thanks to everyone who replied

Rob_DOHC

iTrader: (4)

Lol, job done.

JesseT

Good that that was solved so easily.

BTW, the air temp sensor is not connected to the fuelling in any way.

Rob_DOHC

iTrader: (4)

Im pretty sure it is mate,

stevealien

iTrader: (1)

power engineering said that the air sensor on left side of metering unit hardly does anything,and that it wouldnt make much difference to anything and is almost useless.
not sure how true that is,but thats what he said

Rob_DOHC

iTrader: (4)

Might have to chew my own words, looks like it has more control over the ignition ecu than fuel ecu!

luxembourgrst

ok well i gone a check my earth near the wiper motor,....
but want do want to say if you switch the yellow plug with a paper clips and if its works the sender is focked but if it works what?? thanks

Rob_DOHC

iTrader: (4)

Sorry i dont understand?

If it works with a paper clip (shorted out) replace the sensor was the advice above.

Rob,

luxembourgrst

i don t under stand this
he also said that it could have been the water temp sensor ( the yellow one underneath inlet mani),and he said that to test it,its ok to bridge the plug with a paperclip,if it works,then sensor is fooked.


if what works if the plug is installed on the blackbox on metering unit and te car run perfectly when the yellow temp sensor is switched?

where ia again the yellow plug sensor ? directly under the cold start blue plug comes there the brown or the yellow? i can remember a intersting picture about a engine who is writing every plug on the back of the engine but can t find this picture again

luxembourgrst

here we go is that correct well the yellow sensor is importent for the ECU (but what ecu motorcraft or the Bosch)

stevealien

iTrader: (1)

yellow temp sensor is as pictured,coming off at an angle below brown thermotine sensor behind inlet manifold.
the one thats a real bitch to get too.
not sure what you dont understand so ill try again.

unplug the yellow plug from the yellow sensor.

put a piece of wire across the plug or a paperclip to bridge the wires in plug.

with everything connected as it should be,fuel ecu,electric fuel valve etc,if vehicle runs ok with bridge,then yellow sensor needs replacing.

if it still runs poo with bridge then something else is at fault,and he said it could be a big can of worms.
which in english,means very hard to find the fault.

check your 2 earths to wiper bracket maate and run a clean earth lead from bettery to them.
good luck,let us know if it works

luxembourgrst

ok thanks understand every thing thanks have to test this

but have to do this test when engine hot cold d on t matter?

stevealien

iTrader: (1)

Doesn't matter. Did mine from cold.