RexRyder

iTrader: (10)

or u could just use that depressure valve on mazdatrix made especially for this?

Aaron Cake

iTrader: (1)

Instead of sending them all the way to Alberta, I have had excellant service from Roy's Diesel in London. Much more local. They have a gas injector cleaning rig as well.

Amur_

Just found it...

http://www.mazdatrix.com/c-bleed.htm


Interesting. I might try to build my own...

They even emphasize on that page -> it won't fix the problem. Ultimately, unless I attack the injectors again I'm just patching over the problem. I'd rather have my engine running properly without extra help. She'll weigh less, for one.

Amur_

Unless you can post an itemized list from them that mirrors or exceeds that site's, I'll be going west with this job.

Aaron Cake

iTrader: (1)

Looked at the site...That's basically what Roy's does, but you don't get a printout of the flow pattern...Injector cleaning isn't really rocket science, even though it looks like your last set got screwed up. There are plenty of places around service injectors.

WAYNE88N/A

We were discussing this in another thread, Hailers. I decided using my 1 brain cell that vac on the FPR would actually tend to close the poppet, not open it (to bleed down the pressure). Look at the design of the little animal. I don't have x-ray vision, but just by looking at it you can tell that the poppet has to move DOWN to allow return fuel to flow to the hose. We all know that fuel pressures alone are enough to crack it open, and the fuel flow moves down from the rail, therefore the poppet must also move down. In other words, it would take positive pressures in the sensing chamber to unseat the spring-loaded valve, not vac...

However, as you well know, I happen to have a spare FPR lying around. I will run my own scientific evaluations on it to determine if vac up top tends to open or close the poppet. Just in case I'm wrong...Just have to find some time between 3 kids and a "honey-do" list that's a mile long, lol...Results pending...

RXSevenSymphonies

iTrader: (2)

Amiuer: Here's how you figure out if your car is low or high impedence

http://www.fc3spro.com/TECH/MODS/FUEL/inj.htm

HAILERS

*****We were discussing this in another thread, Hailers******

Let's save you some time Mr. Wayne. In the fsm its says you should have approx 28psi at idle. Then later it has you pull the vac hose off the fpr. The fuel pressure then should go to approx 39psi. Soooooooooooo.....vacuum equals less rail pressure..........atmospheric pressure equals higher pressure. Actually atmospheric pressure or boost pressure equals higher pressure in the rail.

I think soon, real soon, I'll attach my fuel pressure gauge then rev the engine to three or four grand then switch the engine off while it's at three/four grand.....and see how far the rail pressure falls. Maybe do this with the foot to the floor once the key is off and the next time just releasing my foot off the gas and see if there is a difference in rail pressure.

Amur_

Reading that, I'd say they're all low impedance (based mostly on cap colour and series.) I'm doing some maintenance after work tonight - I'll check the resistance of the secondaries (if I remember. )

RotaryResurrection

iTrader: (8)

http://www.rotaryresurrection.com/ro.../injector.html

BTW, that m'trix bleed valve is a piece of ****. I've yet to see it work. I have seen it fail and make a car not run...never building enough pressure at the engine to fire up.

Amur_

Low impedance all around, then (I wasn't able to check the injectors like I'd hoped...)

And I'll forget about the bleed valve, then.


Now that we know, what was the suggestion?

WAYNE88N/A

OK, Hailers, I'll buy that for $1. That would mean that the vac source is acting differently than what I'm thinking (pulling it down instead of pulling it up). Intriguing. Maybe I'll cut mine in half for a little reverse engineering project. You sound like you're having fun with your fuel pressure gauge, I gotta get one too now

That's about all the hijacking I can do for now, Amur, lol...

RotaryResurrection

iTrader: (8)

This works for any low resistance 86-7 car running the stock injectors, resistor pack, and harness.

Find the resistor pack under the air filter box. Note there are 5 wires on each side of the plug. The outside 4 feed 12vdc+ to each of the 4 inejctors, while the ecu triggers ground directly via 4 other wires to open them. The center wire of the 5 is thicker than the rest, the familiar black and yellow 12vdc+ wire that supplies many important functions in the car. This is the power input to the whole injector circuit.

The idea here is that you can have better success with a fuel cut switch if you interrupt the injectors opening signal itself, then just depriving them of some fuel pressure via the pump. The 89+ cars have this function programmed in to the ecu, just by pressing the throttle to WOT during cranking, you can cut off the fuel injectors in those cars. Some smart electrical guy could take it so far as to hook up a 1-2 second automatic delay to the injector circuit, so that the engine cranks over and builds its compression before fuel is ever shot in. This should negate the need for a fuel switch altogether, and it would let Amur use his type R mad JDM style remote starter.

The procedure is to cut this supply wire and make wire runs into the cabin to your switch, to interrupt the power supply to the injectors. IT's easy to do on 86-7 low impedance cars, because the wiring is exposed by the resistor pack. High impedance 88 models can be rewired as well, but you actually have to get in by the ecu and find the wire(s) in that big mess, cut them and connect your wire runs and switch, so it's not quite as easy. For reference on those cars, you'll find 2 large plugs above the ecu up in the kick panel...on one of those will be 2 thick black/yellow wires, these are the injector power supply. BOTH must be cut and run into one, run to your switch, then brought back and reconnected to BOTH of the remaining wires that you cut.

RotaryResurrection

iTrader: (8)

BTW wayne, Hailers is right, and I said the same basic thing earlier. Vacuum pulls fuel pressure down, atmospheric and boost raise it. So in theory, applying vacuum to an FPR will *help* it open farther than it would otherwise have, allowing some fuel pressure to be released.

HAILERS

I did some fooling around with my fuel pressure gauge today. It seems I was just a touch wrong in my above post. Nothing serious though.

Just reving the car to three grand and shutting the engine off does very little in the fuel pressure area. It just causes the fpr to regulate down to 28psi , no lower.

If I use the fuel cut switch to kill the engne at idle, the pressure drops way down to 15psi. No lower but a lot lower than 28psi.

If I use the fuel cut switch to kill the engine, but rev the engine to three to four grand prior to switching to off with the fuel switch, then after the engine dies the pressure is zip, zero. To clarify, I held the revs to b/t three and four grand and held the pedal down as the engine died of fuel starvation.

Anyway, the key point is that if the engine is at a idle and you use the fuel cut switch to kill the engine, your still going to have approx 15psi in the rail when your done. The only way to get zero psi is to hold b/t 3-4 grand then hold that tpm after switching the fuel cut sw to OFF.

Amur_

Kevin - I *suspect* that you've just pointed me to the wire that the fuel cut-off device thingy is supposed to tie into. Now I just have to find out for sure...


HAILERS - help me understand... What is the difference between this:


1

and this:

2

Are you saying that in 1 you blipped the throttle and hit the switch at 3k? And that in 2 you held the throttle above 3k, hit the switch and matted the pedal as the engine died? Or just held the pedal in place as she died?