Fuel Pump Relay 9434225 Examinations 1998 v70 non turbo

[foggydogg]

I am stunned at the amount of time and bandwidth spent on a part that is available for $35, and the old worn out piece should go to the landfill.

[scot850]

I understand your position on this foggy, but keep in mind these parts may not always be available new, so having a way to repair may be the only option. Owning an AWD car soon teaches you to have to repair and modify parts as new are not available and in some cases for over 5 years and more.

Neil.

[abscate]

Harbor freight had the three piece

Waveform generator
2Ghz storage scope
Fuel pressure gauge

On special just last month.

[850oldschool]

Harbor freight had the three piece

Waveform generator
2Ghz storage scope
Fuel pressure gauge

On special just last month.

All I can find is the fuel pressure gauge. Do you have part numbers for the other two?

[MrAl]

Couldn't you do a quick check of the health of the relay/pump system by making a small wiring harness with appropriate connectors which would allow you to tap into the circuit and monitor the voltage output from the relay on an oscilloscope? And possibly also read the current draw of the pump? Although the current draw would need to be correlated with pressure to provide a meaningful benchmark.

Hi,

Yes if you could get the connectors. We'd need a socket for the relay and a socket from an old relay to make a harness. That would only give us access to the four terminals of the relay though. I wanted to test other points inside the relay on the circuit board too.

I didnt have any connectors and not sure where to get them so i soldered wires to the points on the circuit board i wanted to monitor and ran them out along side the bottom connector so the case would still slip on normally and stay on. I then could connect test equipment to the leads coming out. I was going to test some other points too but i dont think i need to now.

And yes a current measurement of the pump would be nice. Maybe in the future i can make that too.

[MrAl]

I am stunned at the amount of time and bandwidth spent on a part that is available for $35, and the old worn out piece should go to the landfill.

Hi,

Well there were several motivating factors at play here.
First, i already spent $2800 on a repair just a few months ago and the same thing happened it stalled and would not start. This leads me to believe that the repair place did not know enough about the car to fix it properly so bringing it back to them would be a waste plus another ripoff.
Then i found out the circuit was easy to access so i went from there. I did a little each day and wasnt in a hurry.

The other factor is i could buy another relay, but how do i know if that one is working properly.

[MrAl]

I understand your position on this foggy, but keep in mind these parts may not always be available new, so having a way to repair may be the only option. Owning an AWD car soon teaches you to have to repair and modify parts as new are not available and in some cases for over 5 years and more.

Neil.

Hi Neil,

Yeah i was thinking about that too, as i see other parts becoming extinct that were not so when i first bought the car. I also see garages that dont want to be bothered by the car either now. I wonder who services these things now.

I had to do similar on my old Hyundai too some parts were not available anymore. I had to make some of my own. What a pain that was.

Used cars are becoming a pricey investment too. Getting another one means a pretty big expense these days.

[MrAl]

Harbor freight had the three piece

Waveform generator
2Ghz storage scope
Fuel pressure gauge

On special just last month.

Hi Steve,

Oh that's interesting, i didnt know HF sold those items. I dont know if i would pay for a 2GHz scope though for this, a cheap handheld would be good enough seeing as a frequency as low as 40Hz could be measured easily with, believe it or not, a $35 oscilloscope the kind sold on Amazon. They use an ARM processor to do all the work, and they work pretty good for that price. Only one channel, but that's really all we need.

I could look up some test equipment that would probably total under $100 easy if anyone is interested, but not sure about the fuel pressure gauge i never used one and never had one and dont know how much they are offhand, but maybe i should get one ?

My main goal here is to find out what is wrong so i know if i buy a part there is a good chance it will be the one that actually fixes the car. I think the garage i brought it too last just threw parts at it and hoped something would work, at my expense.

[MrAl]

Harbor freight had the three piece

Waveform generator
2Ghz storage scope
Fuel pressure gauge

On special just last month.

All I can find is the fuel pressure gauge. Do you have part numbers for the other two?

Hi again,

If you want a scope and generator that isnt too expensive i can find them on Amazon for you if you like. For this particular test set we dont need an expensive scope, and almost all of them today have a storage function, even for $35 USD or thereabouts.
I'd love to have a 2GHz scope but dont want to pay for one
Even good waveform generators have come down in prices over the last 20 years. The one i have was probably $200 when new now you can get one easy under $100 and for this particular test even less.

[abscate]

The right way to diagnose these is with the jumper wire as noted above. The only failure mode this would not capture is the absence of the ECU enable waveform but that failure is so rare it’s not worthy of mention other than passing.