No feed to fuel pump

[Life]

Hi, I'm not getting a feed to the fuel pump, Wires at the top of the relay are getting power, If I hook a wire up from thick red/blue in the relay to top of pump it will keep buzzing and I can turn the car over, Got a new relay coming tommorrow, Any other ideas? -Thanks

[Grim Reaper]

crank sensor??? read in another thread that it will not allow fuel to pump

[Life]

Originally Posted by Grim Reaper

crank sensor??? read in another thread that it will not allow fuel to pump

Hi, I put a new crank sensor on, Got a spark, I have fuel when I put a live feed to top of the fuel pump and it turns over. What could cause no feed to the fuel pump from the relay? All wires at top of relay are live. :-) -Thanks

[Grim Reaper]

im sorry i cant really comment more i just read the above in another thread and thought it might help sorry lol

[Bazza_84]

is the wiper motor earthed properly?

[Life]

Originally Posted by Grim Reaper

im sorry i cant really comment more i just read the above in another thread and thought it might help sorry lol

Thanks for your help mate, Very much appreciated! :-)

[Life]

Originally Posted by Bazza_84

is the wiper motor earthed properly?

How do I check that? The wipers keep going off for some reason randomly. -Thanks :-)

[MSG]

Possible problem with your FPR relay itself, i.e. burnt tracks on the internal pcb, also check if initially when you first start cranking does the relay cut in even if it is just for a few seconds to enable the engine to start before other sensors then keep the relay energised.

[Life]

Originally Posted by MSG

Possible problem with your FPR relay itself, i.e. burnt tracks on the internal pcb, also check if initially when you first start cranking does the relay cut in even if it is just for a few seconds to enable the engine to start before other sensors then keep the relay energised.

Hi the relay keeps clicking, sounds like its sticking, I will change it when I get back from work, Thanks

[MSG]

Originally Posted by Life

How do I check that? The wipers keep going off for some reason randomly. -Thanks :-)

Bazza-84 suggested an earthing problem that may be related to fuel pump relay circuit as well as the wipers, so he asked about your wipers and you said they are going off randomly, so that may be indicative of a probelm either bad earth or a blown fues feeding through other circuits such as the wipers, so get all fuses cheched and earthes.

[tathan]

Or it could just be the relay.

[Life]

Originally Posted by MSG

Bazza-84 suggested an earthing problem that may be related to fuel pump relay circuit as well as the wipers, so he asked about your wipers and you said they are going off randomly, so that may be indicative of a probelm either bad earth or a blown fues feeding through other circuits such as the wipers, so get all fuses cheched and earthes.

Will do, Changed the relay still the same, So cant be that, :-)

Any other ideas? -Thanks

[Life]

Checked all earths, fuses, The relay for the wipers clicks in and out, the wipers are stuck on for some reason, Any other ideas? :-)

[MSG]

Have you checked wiper fuse and also see if they have a good earth.
Are you getting spark?
and is there a positive voltage reading to your injectors when cranking.

check these 3 items first and check all other fuses too.

Fuse 11 feeds the fuel pump, and also the feed for this fuse comes from the FPR which also supplies unfused 12V to the oxygen sensor heater if yours is a 3 wire sensor, meaning that if the wire to the sensor heater is shorted out then no matter how many relays you use they will burn up internally!!! bad circuit design, as there is no fuse in the path of this oxygen sensor heater wire Red/Blue, check that it is not shorting to earth, if it is it blows a track on the relay and that in turn will not run your fuel pump. One way to check is if this is not the case is to see if you are getting a feed to the fuel pump even if it is for a split second or two.

[MSG]

To determine if the FPR Functions ok (assumed with Motronic 1.5 ecu)
Operation:
Firstly put a DVM with the black lead to negative or to vehicle earth or chassis, and red lead to pin 85, then observe when you crank engine, pin 85 must go Negative, normal reading when not cranking should be +12V on a DVM, when cranking pin 85 must go negative (0 volts) This may last only a few seconds as you are cranking the engine. The ecu sustains this negative voltage if all else is fine with things like signals arriving from crank sensor, and possibly from the AFM, but will not sustain it if there is a problem from the crank sensor. (assuming there isn't any immobiliser issue)

Next check that you have +12v at pin 86 a thin red wire .75mm (This is unfused wire so be carefull) also check there is a +12V at pin 30 which is a thick red wire 4mm unfused.

If so far Ok, then switch off ignition and now perform this next stage test

Now place the Red probe from your DVM to battery +ve or use pin 30 which is 12v+, and place the black probe from the DVM to pin 85B of the relay module, switch on, and start cranking while you observe if you can get a 12volt reading on your DVM, as the engine is cranking the reading may be as low as 9V due to the load on the battery, when not cranking it may read 12v but may only last a second or two.

If the above test passes, that means the ECU is sending another negative pulse to pin 85B to switch on a second realy whose contacts then feeds a +ve voltage via its contacts to supply a positive feed to the Heated Oxygen sensor (unfused) and also to Fuse F11 which in turn supplies +12v to the fuel pump.

Therefore you should seea +12V at pin 87B


To test fuel pump working when you don't know if there is any probelm with your FPR relay then bridge pin 30 to pin 87B, this should start your fuel pump and supply +ve voltage to injector rail.

However even if your fuel pump is pumping and injector rail has a +ve voltage, that engine may still not start because of other problem such as the signals not arriving from the crank sensor and from the AFM to switch on the injecors. But if you are getting a spark, then that is a good indication that the crank sensor may be working and that you should also suspect your Camshaft phase sensor that determines the firing order and is necessary for the engine to start

Other than that I can only help you further if you can tell me which signal is missing either at pin 85 or pin 85B both of which comes from the ecu, and as you said the relay is clicking and then dropping out so that points to sensor failure in my view.


(but remember the test can only be as sucsessfull as your ability to make proper contacts with these pins using the DVM probes)

[MSG]

If you bypass the ecu controls over the fuel pump, (by bridging pin 30 with pin 87B) does your engine fire and run oK?

[MSG]

sorted the guy's problem, finally after exchanging quite a few PMs, taking him through stages, traced the fault down to broken wire inside the sheath near the fuel pump terminal, which is what I feared may have happened, but to actually get the section where the break occurs can be difficult to see, it can only be felt and so the guy sucsessfully sorted that weak section, he was only getting 8.2V at the red/blue wire at the fuel pump end, wires had corroded inside the sheath , causing a big voltage drop, and after he wiggled the wires it burts into action, thus locating the position of the fault near the terminal crimp but inside the wire sheath.

Now sorting out his wiper probelm that has nothing to do with fuel pump. Possibly a wiperv relay issue. His wipers turn on as soon as he turns the ignition on even though his wiper switch is set to off position. He will come back in the morning after I have asked him to swop the two wiper relays one for the front and one for the rear wipers, so if the relay is faulty the problem should transfer to the rear wipers. if it does then a faulty realy which should be replaced.

[Life]

Hi, Problem solved thanks to MSG! Turned out to be a duff wire running from back of fuel tank not keeping a constant 12v feed and dropping. A big thankyou to MSG for his patience while trying to find the problem, really appreciate it mate, Thanks!

Will post some of the information I have recieved through PM's from MSG, Will be a very useful thread for people to come back on in the future.

[cyndi]

to msg,

would the "dvm stuff" be the same for 2l 16vecotec with simtec 56.1

as im trying to work out whats wrong with mine
it seem to lose power abit ,coughed and and died up road a bit futher,i have changed FPR and check for spark which is there,changed fuel filter,when i found bottom crank sensor wiring not at all good i thought i had got it so changed that, but still no joy ,it turns over but will not start .

any ideas.
cheers steve

[cyndi]

any ideas guys or MSG for above post

i have read today that there are differnet crank sensors ,i changed mine cos i found wiring shot
but it didnt resolve it ,so thought it was something else ,but i will no check im getting volts at ssensor on cranking.

[MSG]

Sorry Cyndi I didn't see your post for two days and today I received your PM, I am looking into your problem and will come back to you on that so check your PM later on. Please accept my apologise for the delay in checking your post and PM.

[MSG]

In general principle, regardless of the type of ecu on your engine, Simtech 5.6 is used on ecotech engines, however this should also control the fuel pump relay in a similar manner to Motronic 1.5, so a similar check can be made by you on your FPR, although I am not ruling out a slight variation on this, so until you try you cannot say if the fpr set up is different on yours, if you can get the voltage readings on the FPR pins stated in one of my posts above, during cranking, and then report back with the results, this will help me identify what the probelm may be.

Save me repeating what to do so follow the procedure in post no 15

[cyndi]

to MSG

sorry its been a few days ,death in the family

right here goes i followed post 15 as good as i could,DVM black to earth then only wire i could find with 12volts on at first then went low with cranking was what looks like 85B (brown/Green),i worked out that this goes to zero volts when i here a click after about a min so must come from immobilser.

the wire which looks to me as 85 is (brown blue) 12volts when ignition off ,zero volts when ignition on .
so im not to sure if you meant 85 /85b the other way round or im wrong or cos its different.

then i checked 12v at 6 thin red ok .
then 12v at 30 thick red ok

then i didnt do the next bit 12v to 85b due to above and not wanting to mess soemthing up.

but i did crank it and get 12 at 87b and at fuse 11.

the FPR does click on off when i switch on ignition and i can here in back a thump on and off which sounds like fuel pump at same time.

hope this helps us get to the end of this road
steve

[MSG]

sorry to hear of a death in your family Steve, please accept my symphty, I hope you will soon overcome your greif.

As I have just signed on, I will need some time to evaluate the readings you have taken and come back to you sometimes later tonight or by tomorrow. I have a feeling we will be able to crack your probem since it helps a lot when someone can take meter readings and it then becomes much easier to figure out the cause.

[cyndi]

help please any one

i thinks it may be the crank sensor ive already put in
how do u test this to see if ti works