That would work to test the pump. But don't leave it connected there. Do it just for the test. If the pump continues to run OK, then maybe it is drawing too much power for the fuel pump circuit. You may have a bad connection someplace or a faulty relay also that would limit the current flow.

To answer your first question, the pump in any NA is full voltage when it is on.

Car running, power the Pierburg directly from the battery, car dies immediately.

Pierburg turns on OK far as I can tell, it whurs and whines loudly.

Random brainstorm:

I don't think the pumps are pumping against each other because priming the fuel system worked fine, and I think the car would run for at least a second or two if that were the case.

The power/ground has to be attached correctly at the pump because Joel used it on his car. (unless he switched it as a horrible, cruel joke for which he will ...nevermind) The wire voltage at the Pierburg (not hooked up to the pump mind you) is 13+ just like at the stock pump, so the power feed is good.

The ground at the Pierburg seems fine also because with the car off, the pump turns on with the power straight from the battery. Ground bad, the pump woudn't turn on I'm assuming to be correct.

About the M.Net post. A "shorted" pump, and I have no idea what that means, would cause these symptoms, BUT the damn thing turns on independently. Also, when I jump the GND and FP at the diagnosis box I can hear the Pierburg turn on and I even crawled under the car to feel the fuel hoses. I can feel the fuel pumping through. When I grab the pump, it sure feels like its on.

Question is, could that just be the stock pump pumping through the Pierburg, the Pierburg making some noises but not actually working?


:vash: :vash: :vash:

Pull the feed, and pull the exit to the Fuel filter. have the feed pull from a bucket of water. give it some power and see how it reacts.

another option. sell the pierburg, get a 190HP?

Did exactly that, except with a bucket of gas. Crazy :).

Pumped fine. Only difference was that this time it was very quiet as compared to before.


Made a vid of the above if you care to see, it's uploading, youtube style.
Also made two more vids. One, the stock pump powered in "prime mode." The second the same except the Pierburg is powered as well. I'll upload and label both, and post again when ready.

Well, I have 3 vids on YouTube:

1. TEST: Pierburg pump - http://www.youtube.com/watch?v=lzC4LmkrRCI
2. Prime mode: Just stock pump - http://www.youtube.com/watch?v=xuoeIer2WF4
3. Prime mode: Stock pump plus Pierburg - http://www.youtube.com/watch?v=5U34UfMacBo


Processing at post time of about 7:50 PM.

Can also search "UofACATS" if the link does not work. Thanks for all your help, fellas.

now that you have it up you can measure the actual flow rating of the pump......

You had the pumps hooked up in parallel, right. That might be dropping the resistance down, and drawing a lot of current. That is probably why your voltage is dropping. When a battery goes under a lot of load the voltage drops down due to the contact area of the plates for the battery not being used efficiently by the sulfides. When you had it hooked up straight off the battery, what was the voltage when you energized the pumps. Check the resistance across the pump leads, and it also sounds like the insulation on the coils has broken down to the point where it is just a giant ground. Try checking the resistance of both wires to the case, and see what it is. Wish you had a megger, that makes this kind of troubleshooting very easy.

get the car to run on the stock pump and see if everything is working correctly.then reibstall the peirburg

Thats a good idea, but when all that is bypassed, it still does not work. Plus, this is how the instructions say to power the pump. Others have been successful doing so.

Just stock pump, works fine.

hey, for shits and giggles. run the pump into a bucket like you did before. this time start clamping on the hose it's dumping out of. This should increase the pressure. I wonder if maybe the pump isn't just old and tired and somehow dies with pressure. Since you should be at 35psi with the OEM pump flowing into it.

When we were trouble-shooting Newbsauce's Pierburg pump his idle went from 35psi to 60psi (BEGi FMU) when we pulled it off. It was casuing a major restriction and hesitation and failed to increase pressure past 80psi where it would completely drop off rapidly. Solution, ripped it out and installed a Walbro 190HP, x10 easier to install and fixed his problems.

Ok, I hear you.

This is Joel's thread on installing the Pierburg. Dated 6-22-2005. Not that old.
https://www.miataturbo.net/forums/showthread.php?t=1651

I have zero problems going with the 190, but it sucks to give up on this.

What sucks more is all I read when researching fueling is that the Pierburg is the best option even though it's the most expensive. That's BS?

I think the 190HP is a better solution and easier to install (and I've got a M1 hardcore DD).

The great thing about replacing the stock pump with the 190hp is you are replacing an old tired fuel pump that might not be up to the task even with the aux inline pump. I had this issue with my MSD inline pump. It would give me over 120psi of when installed, but the stock pump was not giving consistant pressure and was causing all sorts of oddity.

Less complicated is better.

Jay

Jay, hear ya too man. It's just what you're saying makes perfect sense, why even bother with the Pierburg?


170. used.

Brain, I see Walbro on your list. Whats a HP 190 going to cost me?

What's the best way (is there?) to definitively test the Pierburg so that I'm not selling a broken pump to somebody? I'm not into that shit.

Theoretically I'll come out ahead on the deal..

190 pump FTW

I've had my pump in and out so many times in the past couple weeks, its seriously a 15 min change now lol