328ijunkie has a question

[328ijunkie]

Yup. I dont know everything ;).

Something i have yet to figure out through my countless hours of pondering about it and minimal troubleshooting.
At my last drift event in my OBD2 M52 87 Dual pump car i had a random cutting out issue in the middle of the day. Felt like fuel starvation so i brimmed the tank only to have it keep happening for another hour or so. Let some friends drift the car and suddenly it went away and was gone for the rest of the even (another 30+ runs). I havent troubleshooted anything just been thinking about what it could be and have yet to land on any sort of answer. In tank pump works. I know i have solid fuel pressure and OBD2 ECU isnt bitching about anything. any ideas?

And if you dont know and your bored, enjoy cutout can be seen a few times in there...:

http://www.youtube.com/watch?v=VkrJXe2c10Q&list=UUHxXcUDn5ecznLZaBtFvnXA&index=1&feature=plcp

[bimmerteck]

Look at the fuel pumps at idle with an inductive amp probe and a labscope then pinch the fuel line a little bit to make them work a little harder.

If one pump's waveform looks erratic, replace it. You can also look for a failing pump to draw more amps under load.

Failing-



Good-

[e30rapidic]

well there ya go!

[325e10]

This was happening to me at the Auto-X over the weekend 2 -3 times a run with at least 3/4 of a tank of gas. External pump has become extra noisy so will attempt to replace that first with a Tre performance pump. See if that fixes the issue. Also texted ya about this but I see you were having the same problem!

[jrdeamicis]

Look at the fuel pumps at idle with an inductive amp probe and a labscope then pinch the fuel line a little bit to make them work a little harder.

If one pump's waveform looks erratic, replace it. You can also look for a failing pump to draw more amps under load.

Failing-



Good-

Good idea,

Do you use a pico scope? I am considering upgrading my current scope and the pico scopes seem pretty nice.

[bimmerteck]

Good idea,

Do you use a pico scope? I am considering upgrading my current scope and the pico scopes seem pretty nice.

I had a pico 2 channel a few years back, but I found the Vantage Pro and an older Vantage worked better for my automotive needs once I outfitted them with 10 foot leads and a few extra accessories. The pico gave great data in my bay but was cumbersome to test drive with due to having to drag the laptop along.

The Snap-on is an expensive way to gain waveform data these days though, so if I was shopping for a portable scope now I'd probably check out the new uScope from AES. It and a low amp current probe can let you try out some basic waveform diagnostics for under $500

uScope


The low amp probe I use for current draw, injector tests, fuel pump tests, ect. is below.
Current Probe

[nrubenstein]

Different driving styles can impact starvation in my experience. If you don't have an accumulator tank plumbed in, you should look at one.

Also, please respond to my email.