HUGE PROBLEM

Gary57 · Post by **Gary57** » Mon Feb 12, 2007 9:08 am

I went to start my car this morning and the fuel pump was pulsing instead of running. Then the relay in the engine started ticking, the same as the fuel pump. I pulled the relay out and put a test light in the pins and the test light was flashing, the same as the fuel pump.

What is the problem?? Please help, my car wont start and I use this car everyday!!!

Vlade · Post by **Vlade** » Mon Feb 12, 2007 9:24 am

huh?

So when you manually shorted the contacts where the relay should go the test light was flashing?

Think it might be your fuel pump acting up, all I can think is that the motor is starting to act out that why you get the pulses.

Gary57 · Post by **Gary57** » Mon Feb 12, 2007 9:36 am

No when you pull out the relay there is no power going to the fuel pump but the test light still flashes, so its not the fuel pump. The fuel pump doesnt pulse when the relay is out but the test light still does.

To me its the signal coming from the ECU.

I am coming up to JHB to get the WOLF fitted and tuned, so its gotta last till then.

ChemCool · Post by **ChemCool** » Mon Feb 12, 2007 10:40 am

I sugget quick test on feul pump any way. See manual. It is quick. just to confirm feul pump.

The Calibrator · Post by **The Calibrator** » Mon Feb 12, 2007 6:39 pm

u do understand that there is a constant 12v at the relay from the ign key and the ecu switches the earth?
Are you measuring the earth or the 12v? if the earth is constant but the 12 v pulses look at your immobilizer circuit.
If the earth is pulsing then the iether the ecu is poked or its recieving an input which is causing it to do that.

Gary57 · Post by **Gary57** » Tue Feb 13, 2007 10:47 am

It is the earth that is pulsing. What sensor could do that??

Vlade · Post by **Vlade** » Tue Feb 13, 2007 10:53 am

ummm the earth as Duane said, comes from the ECU

The ECU pulls to ground when the it switches on the Fuel Pump

it initially primes it for 2/3 seconds with you switch on the ignition, then starts it again when you start the car.

There is no sensor to pickup fuel pressure or what not, check if you don't maybe have a loose wire or a short.

On the passenger side, there is a white plug just under the clove box, the fuel pump wire goes there and then into the ECU harness. What wire I can't remember exactly... think it was white or orange... really can't remember, rather check the service manual

Check with a Multimeter if you get continuity between that wire and the body initially when you switch on the car, that should last only a few seconds then why you start it should give you a continues continuity if the wire directly from the ecu pulses you might sit with a buggered ecu.

Gary57 · Post by **Gary57** » Tue Feb 13, 2007 11:23 am

I will try that, will do a proper check tonight and see. I just need the car to run a bit longer untill I come up to joburg and get the car tuned.

Gary57 · Post by **Gary57** » Wed Feb 14, 2007 8:34 am

Ok so I went to fix my car last night. Pulled a coil pack to see if I definately dont have spark, when I tried to swing it it started

. So I then tried everything to get it to do it again, which it did for like 2 seconds, but nothing it just kept on running. I then ran all the ECU tests and still no fault.

So this morning I started it, perfect, on the way to work it broke down

. My dad come to give me a toe but before that we again tried to find the problem, on the side of the road mind you. You can hear the relay in the motor bay clicking away doing its own thing. Anyway I started wiggling the wires around on the ECU, it would stop clicking then start again and stop then start. I then banged on the computer and that worked. The car started find 1st time and I am now at work with it.

But I still havent found the problem. The car drives fine now so that rules out any sensors being poked. I think there is a dry joint in the ECU or something. Any ideas on how to spot it?? Maybe there is a bit of moisture in the box, how can I get it out - Q20 spray??

Vlade · Post by **Vlade** » Wed Feb 14, 2007 9:39 am

shir... at least you narrowed it down... not sure how/what dry joints are

Gary57 · Post by **Gary57** » Wed Feb 14, 2007 9:56 am

A dry joint is when the solder cracks off around the wire where it connects onto the board. I am coming up this friday to get it tuned on Monday, so just hope it lasts till then.

Toby · Post by **Toby** » Thu Feb 15, 2007 6:47 am

Use a magnifying glass, or just go over all the solder joints. If there are too many, go over the more obvious ones, like the fuel pump output, etc. If you have it in a state where it's not working, then very carefully open the ECU, and start doing continuity tests, or else do continuity tests and then bang it to see which inputs/outputs are suspect. Personally, I would go over all the solder joints with a soldering iron to be sure, 'cos the moment you fix one, the next one acts up

widowmaker · Post by **widowmaker** » Thu Feb 15, 2007 10:13 am

Gary57 wrote: I then banged on the computer and that worked...

Gary57 wrote:A dry joint is when the solder cracks off around the wire

uhhm