FPD Again?
#26
Recovering Miataholic
Thread Starter
with the harness, removing the solenoid rack is the hard part, so its a couple more hours, but you're like half way.
I am waiting for a price quote from Ray Crowe's folks. I have a quote of $1286 for the main harness from Huntington Beach Mazda, and $252.32 for the fuel injector. (Hopefully Ray is cheaper.)
#28
Moderator
iTrader: (3)
Join Date: Mar 2001
Location: https://www2.mazda.com/en/100th/
Posts: 30,847
Received 2,606 Likes
on
1,849 Posts
@j9fd3s,
Thanks again. My 1994 parts catalog lists the engine harness (Illustration #1) as part number N3A1-18-05ZE (alternate is N3A1-18-05ZF). is the "-05ZG" part functionally different or just an update (maybe from another supplier)?
Also considering replacing the harness Illustration #2 with P/N N3A3-18-05Z. Does this make sense?
Thanks again. My 1994 parts catalog lists the engine harness (Illustration #1) as part number N3A1-18-05ZE (alternate is N3A1-18-05ZF). is the "-05ZG" part functionally different or just an update (maybe from another supplier)?
Also considering replacing the harness Illustration #2 with P/N N3A3-18-05Z. Does this make sense?
the little ignition harness usually is ok, and actually isn't too bad to change by itself, although you're in there...
#29
Recovering Miataholic
Thread Starter
The wire harness replacement may be moot, for me. I took a second look at the installation and decided the routing through the firewall is inaccessible, unless I remove the entire ABS assembly. Not happening! Getting air in that unit would be un-fixable with my garage equipment. Bleeding wouldn't do it.
#32
Recovering Miataholic
Thread Starter
Hadn't thought about removing the fuel rails & hoses. Thanks for that info. Will take another look. Meanwhile, I have yet to receive a price & availability response from Ray at Malloy Mazda.
#34
Recovering Miataholic
Thread Starter
Sgtblue,
Thanks for the photo with connectors identified, that will help a lot! Hopefully buying it new includes the covering over the leads, not just the wires as shown in the pic.
OK, you forum wizards have convinced me that it can be done. Looks to me like I only have to remove the fuel hoses and the brackets holding the harness to get the current one out. Probably will tie a nylon rope around the passenger cabin end of the new one and feed that through the firewall. Then ask wife to gently guide connectors and harness into the cabin while I feed the harness in from the engine compartment. Hopefully that will work. It's still scary.
WAIT...WAIT...WAIT! What are the "Manual Transmission Disconnects" in your picture? Where do they go and what do they do?
Thanks for the photo with connectors identified, that will help a lot! Hopefully buying it new includes the covering over the leads, not just the wires as shown in the pic.
OK, you forum wizards have convinced me that it can be done. Looks to me like I only have to remove the fuel hoses and the brackets holding the harness to get the current one out. Probably will tie a nylon rope around the passenger cabin end of the new one and feed that through the firewall. Then ask wife to gently guide connectors and harness into the cabin while I feed the harness in from the engine compartment. Hopefully that will work. It's still scary.
WAIT...WAIT...WAIT! What are the "Manual Transmission Disconnects" in your picture? Where do they go and what do they do?
#35
RX-7 Bad Ass
iTrader: (55)
If you want to totally pull the engine harness out:
- Unplug connectors at ECU, make sure to unbolt the 10mm ground wire. Also there are a white and a blue connector up against the firewall, unplug them. There's a harness cover held on with 2 10mm fasteners, unbolt that.
- Unbolt the various 12mm bolts that hold the ABS pump down and wiggle out/remove the ABS heat shield. That will give you some extra working room.
- There are a few connectors that connect to the transmission - speed sensor, reverse sensor, etc. Jack up the car and unplug. The harness runs along the top of the transmission.
It sounds like a bigger project than it is. Getting it off the transmission and out of the firewall isn't hard at all. Getting all the connectors off the engine (CAS, OMP, etc.) is what takes more time IMHO.
I normally only pull and mess with harnesses when I'm pulling the engine. If I were in your shoes, I'd repair what needs to be repaired on the harness with it in the car and go on about my life.
Dale
- Unplug connectors at ECU, make sure to unbolt the 10mm ground wire. Also there are a white and a blue connector up against the firewall, unplug them. There's a harness cover held on with 2 10mm fasteners, unbolt that.
- Unbolt the various 12mm bolts that hold the ABS pump down and wiggle out/remove the ABS heat shield. That will give you some extra working room.
- There are a few connectors that connect to the transmission - speed sensor, reverse sensor, etc. Jack up the car and unplug. The harness runs along the top of the transmission.
It sounds like a bigger project than it is. Getting it off the transmission and out of the firewall isn't hard at all. Getting all the connectors off the engine (CAS, OMP, etc.) is what takes more time IMHO.
I normally only pull and mess with harnesses when I'm pulling the engine. If I were in your shoes, I'd repair what needs to be repaired on the harness with it in the car and go on about my life.
Dale
#36
Recovering Miataholic
Thread Starter
Dale, I've been on again-off again about the harness, but after getting a good look at Sgtblue's pic above, I realize that I have no easy access to some of the endpoint harness locations, such as the OMP, CAS, that you mentioned. So now I think I'll let the old harness be and just replace the fuel injectors. Connectors with broken locking tabs will just have to be touched with with some red Permatex gasket maker and pushed into place. When the engine needs an overhaul, then the harness can be replaced with engine out of car.
Thanks to everyone for your help!
Thanks to everyone for your help!
#37
Recovering Miataholic
Thread Starter
Now awaiting two new fuel injectors & seals. Ordered from Ray Crowe, price $192.23 ea. Checked price here at Huntington Beach Mazda: $252.32 ea plus 8.25% tax. Amazing.
#38
Rotary Enthusiast
iTrader: (32)
Dale, I've been on again-off again about the harness, but after getting a good look at Sgtblue's pic above, I realize that I have no easy access to some of the endpoint harness locations, such as the OMP, CAS, that you mentioned. So now I think I'll let the old harness be and just replace the fuel injectors. Connectors with broken locking tabs will just have to be touched with with some red Permatex gasket maker and pushed into place. When the engine needs an overhaul, then the harness can be replaced with engine out of car.
Thanks to everyone for your help!
Thanks to everyone for your help!
#41
Recovering Miataholic
Thread Starter
Did you ever get a quote from Ray on a new harness?
If you are considering a new main engine harness, you might want to check out Rywire's harness ($649 on their website). You might also be interested in this video
#42
Rotary Enthusiast
iTrader: (32)
The Rywire harness is a good product but it does not have all the plugs to retain the airpump system as I recall. That rules it out for a CA vehicle that has to undergo smog check. If they offered a complete harness then that would be a good proposition.
$850 for a brand new main harness is a lot of money but it seems like a bargain compared to nearly $400 for a couple of new injectors IMHO.
$850 for a brand new main harness is a lot of money but it seems like a bargain compared to nearly $400 for a couple of new injectors IMHO.
#43
Recovering Miataholic
Thread Starter
@jza80,
You are right; thanks for the info. Here is their list of connectors:
I don't see the three ACV connectors or the air pump signal connector.
Two separate issues for me... one of the injectors leaks fuel around its seal; the harness has connectors with a few broken locking tabs. I went for two new injectors and am waiting on delivery.
You are right; thanks for the info. Here is their list of connectors:
The harness has connections for:
Coolant Temp (for ECU)
Knock Sensor
Injectors 1-4
Ground for the ECU
Oxygen Sensor
Coolant for gauges
Throttle Position Sensor (TPS)
Intake Air Temp (IAT)
4 transmission connections
Fan Switch
Cam & Crank sensors
Oil monitoring pump
2 ECU plugs & 2 chassis plugs
Plus a ground for the cam and crank shield
And 2 extra wires for adding whatever you need
Coolant Temp (for ECU)
Knock Sensor
Injectors 1-4
Ground for the ECU
Oxygen Sensor
Coolant for gauges
Throttle Position Sensor (TPS)
Intake Air Temp (IAT)
4 transmission connections
Fan Switch
Cam & Crank sensors
Oil monitoring pump
2 ECU plugs & 2 chassis plugs
Plus a ground for the cam and crank shield
And 2 extra wires for adding whatever you need
$850 for a brand new main harness is a lot of money but it seems like a bargain compared to nearly $400 for a couple of new injectors IMHO.
#44
Recovering Miataholic
Thread Starter
Pics below are of my "old" (current) fuel injectors. I measured the OD of both uncompressed O-rings on the injectors at 0.850" (21.6 mm). Then I measured the inside diameter of the fuel distributor bore at 0.863" (21.9 mm). Seems to me that the O-rings must have originally been 22 mm or so, but have been "squashed" over the last 21 years. They are also more like plastic than rubber.
So, is it possible I don't need new injectors (which I have already ordered), but just new O-rings? I can't see anything around the electrical connectors that looks bad. Also I really can't see a way for fuel to get inside the electrical portion of the injector. Although when we tested them, the fuel did seem to come up around the electrical connector on the leaking injector, so I assumed that was what was happening.
So, is it possible I don't need new injectors (which I have already ordered), but just new O-rings? I can't see anything around the electrical connectors that looks bad. Also I really can't see a way for fuel to get inside the electrical portion of the injector. Although when we tested them, the fuel did seem to come up around the electrical connector on the leaking injector, so I assumed that was what was happening.
#45
Moderator
iTrader: (3)
Join Date: Mar 2001
Location: https://www2.mazda.com/en/100th/
Posts: 30,847
Received 2,606 Likes
on
1,849 Posts
i see them leak around the electrical pins, and there isn't a seal for that...
when you get the new ones you'll notice that your old ones are quite badly faded, they used to be purple
when you get the new ones you'll notice that your old ones are quite badly faded, they used to be purple
#46
Recovering Miataholic
Thread Starter
@j9fd3s,
Thanks for the info. My approach now is to install new O-rings on the old injectors and test them under pressure. If they still leak, I will ask Ray to send the two new ones that are due to arrive at his place today. Until then, I asked him to hold them for me. If no leak, I will let him know and he can do whatever with them.
FWIW, I am having trouble seeing any way the electrical connector can leak. It looks like the plastic connector assembly contains a coil that energizes the pintle assembly by magnetic induction, although I admit that is speculation. If so, the connector assembly can never see fuel. I do admit, though, that the leak appeared to be coming from the connector area.
Thanks for the info. My approach now is to install new O-rings on the old injectors and test them under pressure. If they still leak, I will ask Ray to send the two new ones that are due to arrive at his place today. Until then, I asked him to hold them for me. If no leak, I will let him know and he can do whatever with them.
FWIW, I am having trouble seeing any way the electrical connector can leak. It looks like the plastic connector assembly contains a coil that energizes the pintle assembly by magnetic induction, although I admit that is speculation. If so, the connector assembly can never see fuel. I do admit, though, that the leak appeared to be coming from the connector area.
#47
Moderator
iTrader: (3)
Join Date: Mar 2001
Location: https://www2.mazda.com/en/100th/
Posts: 30,847
Received 2,606 Likes
on
1,849 Posts
@j9fd3s,
Thanks for the info. My approach now is to install new O-rings on the old injectors and test them under pressure. If they still leak, I will ask Ray to send the two new ones that are due to arrive at his place today. Until then, I asked him to hold them for me. If no leak, I will let him know and he can do whatever with them.
FWIW, I am having trouble seeing any way the electrical connector can leak. It looks like the plastic connector assembly contains a coil that energizes the pintle assembly by magnetic induction, although I admit that is speculation. If so, the connector assembly can never see fuel. I do admit, though, that the leak appeared to be coming from the connector area.
Thanks for the info. My approach now is to install new O-rings on the old injectors and test them under pressure. If they still leak, I will ask Ray to send the two new ones that are due to arrive at his place today. Until then, I asked him to hold them for me. If no leak, I will let him know and he can do whatever with them.
FWIW, I am having trouble seeing any way the electrical connector can leak. It looks like the plastic connector assembly contains a coil that energizes the pintle assembly by magnetic induction, although I admit that is speculation. If so, the connector assembly can never see fuel. I do admit, though, that the leak appeared to be coming from the connector area.
tech tore the thing down, pressurized the system, sure enough, damper was bad.
replace damper, and recheck, and still fuel leak.
after some poking around, its leaking from the injector pins. replace injectors, recheck, and fixed.
#48
Recovering Miataholic
Thread Starter
Ray agreed to send me the O-rings and hold the new injectors until after I test. We'll see. Two upper + two lower O-rings = $47.12. Two injectors = $384.46. Obvious which way I would prefer to go. We'll see.
#49
Recovering Miataholic
Thread Starter
Brand New Problem
I've been marking time waiting for new O-rings from Ray Crowe. The car has been on jack stands from the beginning of this job, and since I removed the existing fuel injectors, the floor under the car has been dry... until today. Wife smelled fuel; I looked under the car and there is a gasoline drip about 1 every 5 seconds from the front suspension member (rear fork) onto the floor. I checked everything that I am aware of on the top of the engine... all fuel hoses, the FPD, the FPR, the primary and secondary rails, and where I could not see, I ran a finger underneath each part/hose connection, etc. Everything at the top of the engine is dry. The ports in the primary fuel distributor are dry all the way down, and of course there is no pressure in the system except for in the fuel tank as the result of some warmer weather recently. I did unscrew the gas cap and got a hiss for a second. But the drip is still there.
If I didn't know better, I'd say fuel is leaking from the turbos, but that's impossible... isn't it? It's definitely gasoline, not oil. From underneath, I can't see above a horizontal sheet metal piece which seems to be the highest point that is wet with fuel.
I'd really appreciate any ideas as to what the heck is going on! A real leak, coming from "nowhere?"
If I didn't know better, I'd say fuel is leaking from the turbos, but that's impossible... isn't it? It's definitely gasoline, not oil. From underneath, I can't see above a horizontal sheet metal piece which seems to be the highest point that is wet with fuel.
I'd really appreciate any ideas as to what the heck is going on! A real leak, coming from "nowhere?"
#50
gross polluter
iTrader: (2)
Fuel pressure in the tank gets the siphon going, fully remove the gas cap and make sure you don't have any fuel line ends in the engine bay that could be below the fuel level in the tank.
I suspect it's going to be your o-rings. I just had to replace mine last year. They were only about 5 years old but one suddenly started leaking. All good now!
I suspect it's going to be your o-rings. I just had to replace mine last year. They were only about 5 years old but one suddenly started leaking. All good now!