Busted Fuel Pump,,,,,
 

Hello,

Yesterday my '85 GSL just quit on me on I-95 at 100... ( I was late)... well, had it towed home. seemed like it just ran outta fuel, (to me thats what it felt like)....I got to the side of the road... tried to start it, it popped a time or 2 then nothing..(quit trying) today I took the fuel hose off of the NIKKI (it was totally dry), turned the key to 'on' & no fuel came out... (gauge says 1/4 tank & I put 2 gallons (at the house) ... its got fuel in the tank..

So, Do I have a busted fuel pump? The last owner included a Holly Red with the car...LOL.... guess that should been a clue. LOL

Holley says mount vertically.... kinda hard considering how low, (&it's getting lower) the car is.
So, does anyone have suggestions upon how to mount this thing vertically.

Thanks Everybody.

With the Holley's output, you would prob need an in-line regulator so you don't flood the Nikki. A lot of pump for the carb!
Mounting has been discussed here, will defer to others, but will suggest you need to be careful in that poor mounting seems to result in a VERY noisy pump. If you are running a stock Nikki, I would suggest getting a replacement OE pump. About $135 new, give or take, or pick up a used one thru the 1st Gen parts for sale area here. Obviously makes the install a breeze too...

Stu Aull
80GS
AZ

I do have the Holley fuel pressure regulator & a liquid/oil filled gauge...

Stock should be around 2.5 PSI.....right?

well, I am gonna have a go at installing the Holley...1. because my truck is in the shop....( they prolly gonna take forever) #2 My motorbike needs service...LOL..
#3.. I already have the Holley... I am about to jack her up & see what I can do....

pump needs to be below the fuel tank, right?

Thanks
Stu.


is there a fuse for the fuel pump? or anything like that?
How much PSI can a stock NIKKI take..?. My car is street ported & has full RB pipe on it.

It could be the fuel cut reply. It can be found near the drivers side right knee under the dash. It can be jumpered. They are pretty expensive.

Thanks,
Is that an inertia switch? in case of a crash or impact?

How can I test that relay or whatever?n just with a 12v test light?

Just called AutoZone..... its open 24 hrs!!! can You believe that? well, he says they have a Mazda OEM for $134.00 lol

Is the stocker my best bet? keeping in mind I plan upon adding a Camden SuperCharger soon, will the stocker flow enough fuel....? I also plan on running a small aux pump to come on around 3-4k revs. with the blower.

Thanks

The relay is a six pin rely. It's not a standard looking relay but easy to test. They go bad so the plug can be jumpered. It's a safety thing but not required.

There are several posts in the first gen technical section about it.

Check the reply before buying anything.

OK, will do....thanks.!

Remove the driver's side storage bin. In there you will find the connector for the fuel pump. It will be a white two pin connector and you can identify it easily as it's wiring runs through a grommet in the body. When cranking, check for voltage at the connector. If you have voltage, apply 12V direct voltage to the connector and see if the pump runs. If the pump does not run with 12V applied directly to it then the pump is bad.

A Mazda oem fuel pump is really the best way to go. Check www.mazdatrix.com for pricing. I think only the early pumps are available anymore but they will work.

if u do replace the fuel pump, make sure to go ahead and replace the filter as well.

Thx All,,, Well, I think I am going to rig up the Holley, mainly because I plan upon getting one of those Camden Superchargers from Atkins Rotary.... & it will need more fuel, I have the fuel pressure regulator to go with it... So I think I should be able to make the NIKKI happy, no?

So, You are saying... if I get this right? find that connector, (my 'smuggler's box's are removed, so it should by easy to find) is it the silver/foil/whatever wrapped one? SO, with key on, there should be power there, Yes? & pump should run..(if pump is good). If there is power & the pump does not run., then the pump is dead, correct?

Thx

& thanks ... the car came with a new OEM fuel filter...I'll throw that in now. I happened to install a FRAM filter I had laying around when I got the car, it looked basically same size & all as the one that was it came with. it was new, so I use it. Is FRAM OK to us in these cars? I use Kendall 20/50 oil.
THX

Oh, the relay thing.... I think I only had 5 wires... 2 were hot---with a wir tin them...& one was hot with no wire. I saw no missing wires or non terminated wires... so? I'm thinking that is a good test? 12v in one....12v out another

Thx again.

well, here it is.... the relay was faulty. I rigged up a jumper wire... & boom power at the connector in the 'smuggler's hatch".

thing is.... it still not right... it runs, but pretty poorly. I remember just before it quit, the REV counter went to ZERO... & that is where it is now.. when I crank it & also when it's running ...No REV counter... What can cause this?
Thanks.

Check your trailing ignitor. Your car is an 85 which will not run the fuel pump unless the relay sees a tach signal (12V square wave) on the trailing (-) coil terminal.

Oh and a Nikki wants 2.5 psi fuel pressure.

This has been discussed at length. I will not use Fram filters in anything. They are not good. Order some Mazda oil filters. They are like 6 bucks or so each and are the best for our cars. I will use Wix and Purolator as they are both proven oil filters. Some people like K&N oil filters but the one in my brother in law's 11 BMW 328 was split in half when I removed it from the filter housing. After seeing that, I'm not sure I'd buy another K&N oil filter. You are using the correct oil weight. Brand is owner's preference really. I prefer Castrol GTX 20w50. Has always been good to me.

Well Folks, I tested the ignitors, as per the Haynes manual... one tested bad... the one under the Alternator..
I plan upon replacing it with a MSD 6-AL... swap the good leading ignitor to the trailing position & run the MSD as the leading ignitor.

Does this sound like a good plan?

Thanks.

Hello, Jeff20B.... now, I jumped the little relay under the dash (by rt. knee) to get power to the fuel pump. So, when I get it put back together with the MSD & the swapped trailing ignitor....Should I re-connect that relay & then power should flow to the fuel pump as it did before the ignitor failure? Yes?

How do I now make the connection to get the square wave from the (-) coil terminal to the
(under dash) relay & the tach?

Thanks Again!

Don't worry about it. It was added in '84 by Mazda as a safety feature. But in my opinion it is very unsafe if your trailing ignitor dies on you and the fuel pump quits. Leave yours in its defeated state or put it back to stock. It's your car and your choice.

On 81-85 cars, the tach is connected to the trailing coil and will also quit if the trailing ignitor dies, as a way to show you without causing an unsafe condition. Mazda did this because if the trailing ignition is not functioning, you would not notice it as it does next to nothing for power. It is just there for emissions. But if your leading ignition dies, you can tell right away as it hardly runs in that state.

Only the 79-80 cars had the tach on the leading coil as they had semi-firing trailing to keep the mixture rich enough to keep the "fire lit" inside the thermal reactor. They also have a tach+voltage meter in the same gauge that has its own wonky issues when it isn't working right.