Shadowscreed

iTrader: (1)

Ok, so my old engine was having problems, and then I blew an oil cooler line, replaced the line fired it up and it died as the built compression leaked from the side of the rotor housings where they meet the center iron. Went to a junkyard and bought a decent/good looking 13B from an 86. My FC is an 88 GTU or GXL, I bought it as a project car. So i bolted the engine from the 86 to my tranny and hooked it up with my 88 harness (I'm not sure if this makes any difference but just in case). I've run through the list and had two bad FPR's so I bought an aftermarket FPR with a gauge, I'm getting about 35-50 psi of fuel pressure or at least that's what the gauge reads. I'm getting spark and I'm running premix in the fuel tank. When I turn the ignition to on and I don't hear the fuel pump, it also doesn't appear to get voltage until I'm cranking the engine, and then the voltage drops steadily.

Is this a wiring issue, or is my pump not working right, or an ignition issue, injectors maybe?

Btw I've tried 3 different fuel pumps and have another unknown pump that is brand new that was laying around at the junkyard still in plastic.

dwb87

iTrader: (22)

So, it's actually a used engine.

When you first turn the key to "ON" you cannot hear the fuel pump prime? Or do you immediately just turn the key to "START"?

Charge your battery and test your alternator. Most all local auto parts stores will test them for free. Also, you need to adjust your fuel pressure to about 28.4 psi. (That is with the vacuum hose connected to the FPR.)

Shadowscreed

iTrader: (1)

Yes it is a used engine, probably should have put that in the title instead, my bad.

I turn it to "ON" to give everything time to prime, it's habit because it's something I've always done with my cars. No I do not hear the pump engage, though it is a used pump from a 90 Plymouth Laser. I have a brand new E8023 Airtex OEM replacement that I found laying around at the junkyard still in packaging (Lucky, right.) that I will be installing and probably be doing a fuel pump rewire this weekend.

I'll try to adjust the FPR to 28.4 like you said, it was reading 60psi last time I was cranking. I also have a secondary rail from an S5 with the stock FPR, should I try that instead of my aftermarket FPR?

satch

iTrader: (1)

The fuel pump will not turn on w/the key to on unless the the engine was running or the fuel check connector was jumpered. Since neither of these are happening then it's normal for you not to hear anything.

Eduardo Santos

I'm not sure, but I've read somewhere that the fuel pump is not supposed to prime. Against what's usual for the vast majority of the cars.

Digi7ech

iTrader: (1)

The fuel pump with key on will prime for a second and then shut off.
Voltage while cranking will severely drop due to the massive power the starter is pulling. A digital multimetter won't be able to keep up with the pulsing power levels. This is where the priming pump helps starting.

You state that you are getting 35-50psi. That's bad. Stock pressure should be 38psi with no vacuum hose connected to the FPR. Too much pressure and you may flood the engine.

There is a yellow 2 pin jumper plug on the passenger strut tower side of the EFI harness. Connect these pins with a piece of wire and turn the key to on. This will turn the fuel pump on constantly.

The fact that you used some random fuel pump also puts that into question.
Go buy a Walbro. They're $100 off ebay and will be enough fuel for a turbo engine upgrade later on.

Then what kind of FPR did you buy? Don't skimp on fuel components. They are vital and if they are crap, they can do bad things. I use Aeromotive FPR and it has worked without issue for 6+ years.

Then there's the ultimate question. How do you know the engine is even good?

Eduardo Santos

Here, read what Aaron Cake wrote in this topic (about the fuel "priming" stuff):
https://www.rx7club.com/new-member-rx-7-technical-256/mixed-wiring-995098/

TReX78788

Easy fuel test: get some carb cleaner and give your intake a good spray... then start the car. If the car tries to start.. maybe run a bit... then you know your getting spark.

If you get combustion, then you know its a fuel problem.

Shadowscreed

iTrader: (1)

Carb cleaner doesn't work. I forgot to mention that the timing is way the **** off, which could be the reason the car was in the junkyard, maybe somehow the timing got screwed and they couldn't figure out what was wrong and said **** it. Cause the 86 that the engine came out of was in excellent shape considering age, it still has the original paint that is slightly sun faded but underneath where the SE spoiler sat was perfectly preserved, all the original glass was good until the last time I saw it (some ******* busted out all of the glass minus the windshield), interior in immaculate shape, engine bay clean, no rust on the car, black painted calipers, engine in good shape with little gunk, dried oil, etc. and the engine has good compression. I know it's getting spark cause I shocked myself with the electrical current while having someone else crank it, had clean coolant and oil, nothing mixed, so on so forth.

I do however know that I clarified the unknown pump is an E8023 Airtex OEM replacement fuel pump, I'll be installing it this weekend, and if anything I need to replace my injectors before going for an aftermarket pump. I bought the FPR from a guy on craigslist, I can check for numbers to find out the specifics of it, all I know for now is that it is an adjustable FPR that is in working condition.

No one answered my question about the stock S5 secondary rail with the stock S5 FPR. Should I use it in place of my adjustable FPR?

Shadowscreed

iTrader: (1)

And I think I goofed big time, someone correct me if I'm wrong but the high pressure fuel line goes into the Primary rail, which connects to the secondary rail which feeds back to the tank. Does the aftermarket FPR go on the feed to the primary or on the return to the tank?

dwb87

iTrader: (22)

No. Adjust your aftermarket FPR to the proper pressure. (~28.4 psi with vacuum.)

(Fuel filter) Feed line -> pulsation dampener (primary rail) -> secondary rail -> FPR -> return line.

Shadowscreed

iTrader: (1)

So my friend stopped by last night and was looking through to see if he could figure anything out and noticed where my feed was sent to and said he wasn't sure but it didn't look right. I looked at my Haynes manual and then double check in my FSM and checked youtube.com, and posted here about how the feed and return is supposed to go.

Here's how I had it ran:

Pump>>>Filter>>>Aftermarket FPR>>>Secondary rail>>>Primary rail>>>return to tank

(Violently smacks forehead)

So today I will be correcting the setup and also double and triple checking my timing. If it runs after all is said and done, I will most likely be posting a vid.

And thanks dwb87 for your help, and to everyone else

Shadowscreed

iTrader: (1)

PS- when putting your engine back together or doing an engine swap, don't listen to your dsm friend on how to put your aftermarket FPR in after removing the vacuum spidering.

Shadowscreed

iTrader: (1)

So I corrected and fuel lines so that they are running how they are supposed to, and also installed a brand new OEM pump and made a short vid of what the engine is doing. I will be testing electrical connections later today for voltage, if everything is good then I will most likely be replacing the injectors. Notice that the FPR isn't getting much pressure. Could this be because the injectors are wide open and causing either too much fuel or are dripping fuel? In either case, would cleaning and flow testing do any good or do they just need to be replaced? Also can an injector clip be wired in backwards or incorrectly?


http://www.youtube.com/watch?v=1JAxM...ature=youtu.be

I know the vid sucks but it was more for sound than video. I'm holding the throttle wide open to get it to run at all

dwb87

iTrader: (22)

It's possible. Or your FPR isn't adjusted properly. I currently have a cheap eBay adjustable FPR... When I loosen the allen bolt on top, it lowers the fuel pressure. When I tighten the bolt, it raises the fuel pressure. (Just something to keep in mind... If that is what you're working with.)

Here is a procedure to see if your injectors are stuck open...

Strap/secure the injectors to the fuel rails. Unbolt and remove the fuel rails. (There's an illustration of this in the 88' FSM. "Fuel and Emission Control Systems" 4A-70) - Obviously you do not remove the injectors or any of the fuel lines. Be sure to set some rags or something under the injector's fuel outlet nozzle, to absorb fuel in case they are stuck open. Jumper the yellow fuel pump test connector at the passenger side strut tower, near the AFM. Turn the key to "ON"... Not to "START". You'll hear the fuel pump running... Now go check the injectors to see if they are spewing/leaking.

If you do not have a Factory Service Manual, here is a link to the 1988 FSM "Fuel and Emission Control Systems": http://foxed.ca/rx7manual/manuals/19...SYSTEMS_NA.pdf

Were the injectors in "known working condition"? They may NEED to be flow tested and cleaned, just for the fact that they're 20+ years old and may have never been professionally serviced anyway. Let's not jump to conclusions, though.

If you choose to get you fuel injectors professionally serviced, I often recommend Witch Hunter Performance. I've always had a great experience dealing with them.

The clips can be placed on the wrong injectors. On a series four N/A, both primary injector clips are on the same stalk. The secondary injector clips are both on the same stalk.

Refer to your FSM.

Pin: 3C - Rear primary (Wire colors: LgB / BrR)
Pin: 3E - Front primary (Wire colors: Lg / Br)
Pin: 3F - Rear secondary (Wire colors: LgR / BrY)
Pin: 3H - Front secondary (Wire colors: LgW / BrW)

Shadowscreed

iTrader: (1)

I set the FPR Using the jumper wire to keep the pump presurrized and attempted to start it then played with the idle screw while having someone else crank it to start it and played with the throttle to see if I could keep it running. Repeated the same process while adjusting the A/F mixture with the set screw on the passenger fender, and adjusted the FPR using the same process. Once the fuel feed and return was set correctly the regulator wasn't reading pressure like it should as you can see in the video so I adjusted while having someone else crank to see if I could find a good point to work with.

The injectors were working with my old engine but i/ know there was sediment in the tank from year old gas. And my last engine had blown coolant seals. On a few occasions with the old engine it would try to die at idle and would cut out at times under acceleration, I wasn't sure at the time if it was related to the blown coolant seals or the injectors but I suspected both equally due to lack of knowledge. Now I'm sure that the injectors were and have been malfunctioning.

As for wiring in the injector clips I have two 460cc high impedance injectors from an S5 engine with the S5 clips wired into my harness for my primary fuel rail. I cut out my S4 clips and my friend wired the S5 clips in where the originals were cut. Is it possible for the wires to be reversed or does it matter/ can the polarity be reversed so that the injectors don't work properly?

satch

iTrader: (1)

The injectors are not polarized.

dwb87

iTrader: (22)

You didn't mention before that you had S5 injector clips and S5 fuel injectors for primaries.

So, you're running:

- S5 primary fuel injectors
- S4 secondary fuel injectors


As you probably know... 88-91 N/A fuel injectors = high impedance and 86-87 N/A fuel injectors = low impedance. Does your car have a solenoid resistor pack?

Shadowscreed

iTrader: (1)

Yes I'm running:

- S5 Primary fuel injectors with S5 clips (which once again were done wrong by my friend. The power wires were run to the smaller wire. I took pics and video and will post them shortly)

- S4 Secondary injectors that are the high impedance that came with my 88.

I also have the resistor pack from the 86 I pulled the engine out of, just in case I had to run low impedance.

dwb87

iTrader: (22)

^ Ah, okay.

It seems that you know what you're doing... Quit letting your friend mess with your car. lol

misterstyx69

iTrader: (142)

If you are running the s5 HI's with the resistor pack ON the harness then you are getting way to much resistance.
you need to bypass the resistor pack.That will give you the Harness an IN and out instead of going through the resistors,and the Ecu will now see the true value of the injectors.
right now,if you are running the HI's with it,the ECU sees about 20 ohms.
If this is what is happening then Satch can elaborate more on it.(if he sees this thread!)

Shadowscreed

iTrader: (1)

Yeah no ****, he tried to say the way he did my FPR was right when I double checked with this thread, google, youtube, my dad, my uncle who is a Master Mechanic with 35+ years experience, other friend, other friend, and my Haynes and the FSM. He's not allowed near anymore rotaries, I think he's just jealous cause he keeps talking about how his DSM is gonna be unbeatable and how a rotary isn't as good as a reciprocating/ piston engine. I just smile and nod... lol

Shadowscreed

iTrader: (1)

I don't have it wired in, I have it as a spare part sitting on the passenger floorboard.

Shadowscreed

iTrader: (1)

Ok, so here all is what I did today. I corrected the S5 injector clips by rewiring them correctly. Got the engine to actually run and didn't get video of it, though I have before and after (of course...). So I got the engine to run and stay alive for a bit, opened the throttle to see if the injectors would cut out and got an undesired result. The engine hit 5,000rpm and sounded like it backfired/ fireballed with a loud pop and died, I was leaned over the driver's side fender when this happened. I saw some wetness on the firewall and it appears the thermal wax blew. Now the engine doesn't sound right at all and sounds like it has a knock, so I'm hoping it's not a blown apex seal(s). Below are pics and vids.

These are pics from before the rewire and a vid showing how the injectors were spraying before the rewire.



Notice the different wires, a 4 year old can match colors....

Vid of injectors spraying before rewire
http://www.youtube.com/watch?v=L4Z3hRslmKg


And this is what happened after it ran and made the loud pop (backfired I think)
http://www.youtube.com/watch?v=NWXAh-PXMR4


Can anyone tell me what this sound is and why I can hear it best through the intake piping and intake box (Note: I removed the air filter because it needs to be replaced and no one has a replacement in stock)

Digi7ech

iTrader: (1)

Set your fuel pressure with no vacuum source. It should be 38psi with car off and jumper plug.

In the video, your gauge read up to 10 and it looked like it blipped to 2. Is that 10psi sweep or 100psi?
Do you have a EFI FPR or is it carb FPR? Carb FPR's are cheap because they only go up to 15psi.

Secondary injectors don't fire until 3800rpm. Before that only the primaries will fire.