FD won’t start CAS issue?
12-20-23, 05:41 PM
#101
Eats, Sleeps, Dreams Rotary
Update guys,
I pulled the trailing plug closest to firewall, cleaned it, stuck it back in and cranked and pulled it out and no gasoline on it.
injectors aren’t firing.
now my next steps are to take off the UIM, and do a click test on the injectors to see if they’re stuck. No clicking means stuck right? I will also get a noid light and attach it to the connector to see if ecu is firing (which I think it is because ecu shows injection percentages).
Billyboy, the place I sent my injectors to were injectorrx, they seem reputable no? Well I hope so.
outside of stuck injectors or the noid light possibly not working, what else could be the issue? Besides those two possible culprits, I’m fresh out of ideas guys
I pulled the trailing plug closest to firewall, cleaned it, stuck it back in and cranked and pulled it out and no gasoline on it.
injectors aren’t firing.
now my next steps are to take off the UIM, and do a click test on the injectors to see if they’re stuck. No clicking means stuck right? I will also get a noid light and attach it to the connector to see if ecu is firing (which I think it is because ecu shows injection percentages).
Billyboy, the place I sent my injectors to were injectorrx, they seem reputable no? Well I hope so.
outside of stuck injectors or the noid light possibly not working, what else could be the issue? Besides those two possible culprits, I’m fresh out of ideas guys
I would bet money the injectors are fine.
They probably just aren’t seeing voltage for some reason.
My guess? The aftermarket harness is less obviously arranged than the old OEM, and you accidentally hooked the up the primaries to the plugs for the secondaries.
Which would mean you wouldn’t be getting any fuel in the engine. Even if the secondaries are firing instead, there isn’t enough air flow to pull the fuel into the chamber (probably lol).
Assuming nothing is physically wrong with the wiring, fuses, relays, etc….
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Xion (12-20-23)
12-20-23, 06:11 PM
#102
Ypu may want to check the leading plug for fuel dampness. The trailing plug is exposed to the chamber through a very (very) small hole, and may simply not be getting wet much.
Although all my coils showed spark, we guessed that the spark might have been weak.
Combined with flooding and bad gas, a weak spark might have been part of the problem.
Although all my coils showed spark, we guessed that the spark might have been weak.
Combined with flooding and bad gas, a weak spark might have been part of the problem.
Last edited by Redbul; 12-20-23 at 06:13 PM.
12-21-23, 12:13 AM
#103
Full Member
Thread Starter
Check 1k yet? If the ECU does not know the pump is running , it might not fire the injectors.
it seems injectors are fed power from the Main Relay through the front harness and then the emission harness (sometimes miss-called engine harness) through connector x-05.
Each injector is connected separately to the ecu at pins 4W, 4Y, 4X and 4Z. through connector B1-01.
I have seen where the front harness is damaged where it passes through the fire wall, perhaps from someone jamming after market equipment wires through the same hole.
The EM harness could be damaged in the same way.
I assume your replacement harness replaced the EM (emissions harness).
it seems injectors are fed power from the Main Relay through the front harness and then the emission harness (sometimes miss-called engine harness) through connector x-05.
Each injector is connected separately to the ecu at pins 4W, 4Y, 4X and 4Z. through connector B1-01.
I have seen where the front harness is damaged where it passes through the fire wall, perhaps from someone jamming after market equipment wires through the same hole.
The EM harness could be damaged in the same way.
I assume your replacement harness replaced the EM (emissions harness).
by front harness you mean the engine harness right? Also emissions harness is part of same said engine harness? My whole engine harness I got brand new from wiring specialties. I will check the 1k on the ecu plug and let you know
12-21-23, 12:16 AM
#104
Full Member
Thread Starter
Hit the injectors with 12 volts.
I would bet money the injectors are fine.
They probably just aren’t seeing voltage for some reason.
My guess? The aftermarket harness is less obviously arranged than the old OEM, and you accidentally hooked the up the primaries to the plugs for the secondaries.
Which would mean you wouldn’t be getting any fuel in the engine. Even if the secondaries are firing instead, there isn’t enough air flow to pull the fuel into the chamber (probably lol).
Assuming nothing is physically wrong with the wiring, fuses, relays, etc….
I would bet money the injectors are fine.
They probably just aren’t seeing voltage for some reason.
My guess? The aftermarket harness is less obviously arranged than the old OEM, and you accidentally hooked the up the primaries to the plugs for the secondaries.
Which would mean you wouldn’t be getting any fuel in the engine. Even if the secondaries are firing instead, there isn’t enough air flow to pull the fuel into the chamber (probably lol).
Assuming nothing is physically wrong with the wiring, fuses, relays, etc….
yup I’m gonna hit the injectors with 12v tomorrow to see if they’re stuck or not. Going for low hanging fruit and will hit the secondaries first since they’re easy to get to.
as for accidentally mixing the primaries with the secondaries I didn’t do that. The harness sent from wiring specialties was labeled with p1/p2 and s1/s2. I also made sure they were in the right order by using the manual and associating the color of the wires with the location.
So what could it be? Like what could cause injector connectors not to see voltage? I got a brand new egi, fuses are good, ecu is good, grounds are good. I got a noid light today and I will test it tomorrow as well to see if they get voltage.
also there is airflow because I put starting fluid on the throttle body and it sucks it in and makes starting noises
12-21-23, 12:17 AM
#105
Full Member
Thread Starter
Ypu may want to check the leading plug for fuel dampness. The trailing plug is exposed to the chamber through a very (very) small hole, and may simply not be getting wet much.
Although all my coils showed spark, we guessed that the spark might have been weak.
Combined with flooding and bad gas, a weak spark might have been part of the problem.
Although all my coils showed spark, we guessed that the spark might have been weak.
Combined with flooding and bad gas, a weak spark might have been part of the problem.
I will take your advice and check leading tomorrow for wetness
12-21-23, 12:43 AM
#106
Study the wiring diagrams.
Front harness appears in the diagrams as (F). It is a huge harness that wraps around the front of the car entering the cabin through the firewall on both sides.
Many of the fuse boxes and relay boxes connect through the (F) harness.
On early cars what most people call the 'engine harness" is called the Emissions Harness (EM) in the wiring manual.
What the manual calls the Engine Harness (E) many people refer to as the starter harness, linkiing the starter, alternator, etc.
I believe what you have replaced is largely the Emissions Harness. Although it is likely highly simplifieed if your Rat's Nest has been substantially deleted.
The short harness for the coils may be referred to as the ignition harness (IG).. It connects to the (E) harness (not EM) and through connector X-12 to the front Harness (F) and from there to connector B1-09 at the Igniter. The ignitor gets its signals from the ecu through the (F) harness. The ignitor gets its signals from the ECU ,referred to as the Power Control Module, through pins 1J, 1G,1H and 1T.
I think you want to check if the injectors are allowing current. Then back check through each of the connectors to see if there is a disruption of current.
Billyboy mentioned the certain grounds. It looks like EM harness as three grounds (3),(4) and (15) that you might want to check again. These grounds are likely wired to your replacement EM harmess. Ground 15 may actually be on the IG harness. It is hard ot tell.
Front harness appears in the diagrams as (F). It is a huge harness that wraps around the front of the car entering the cabin through the firewall on both sides.
Many of the fuse boxes and relay boxes connect through the (F) harness.
On early cars what most people call the 'engine harness" is called the Emissions Harness (EM) in the wiring manual.
What the manual calls the Engine Harness (E) many people refer to as the starter harness, linkiing the starter, alternator, etc.
I believe what you have replaced is largely the Emissions Harness. Although it is likely highly simplifieed if your Rat's Nest has been substantially deleted.
The short harness for the coils may be referred to as the ignition harness (IG).. It connects to the (E) harness (not EM) and through connector X-12 to the front Harness (F) and from there to connector B1-09 at the Igniter. The ignitor gets its signals from the ecu through the (F) harness. The ignitor gets its signals from the ECU ,referred to as the Power Control Module, through pins 1J, 1G,1H and 1T.
I think you want to check if the injectors are allowing current. Then back check through each of the connectors to see if there is a disruption of current.
Billyboy mentioned the certain grounds. It looks like EM harness as three grounds (3),(4) and (15) that you might want to check again. These grounds are likely wired to your replacement EM harmess. Ground 15 may actually be on the IG harness. It is hard ot tell.
Last edited by Redbul; 12-21-23 at 01:05 AM.
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Xion (12-21-23)
12-21-23, 01:09 AM
#109
Full Member
Thread Starter
oh man you’re a genius I’m going to do this. I totally forgot I can unbolt those solenoids on the side of the UIM and just work there. Will do that. Btw what aftermarket harness you got? That isn’t from wiring specialties is it?
12-21-23, 01:14 AM
#110
Full Member
Thread Starter
https://www.wiringspecialties.com/13...ess/#gallery-1
that’s the link to the wiring harness I have. It shows pictures of it there. Ya the emissions harness for the air pump, egr etc are all part of the engine harness. Isn’t that how the OEM harness is?
12-21-23, 01:59 AM
#111
I am surprised you still have the twin solenoids!. Be very careful not to break any of the four nipples. Expensive to replace if you do. (Although I would change out that green solenoid set with new.. Yours could be 30 years old)
The tuning shop that rebuilt my engine is called ForceFed Performance in Abbotsford B.C., The reliability mod build was pretty extreme in eliminating emissions and sequential turbos solenoid /acuum systems.
They had their own wiring specialist.
Seven years on I am slowly learning what all they did, haha.
47,000 km since my rebuild. I posted the compression numbers above.
Pretty pleased at this stage of engine life, but I was to complacent on the state of the remaining vacuum hoses.
It seems the vacuum line to my FPR was totally crumbling meaning the FPR was not being held open enough.
Hopefully my easy flooding issue is cured.
Also got my AFR sensor replaced and it is showing the car idling pretty lean.
So likely the tune is not too rich for low revs..
That big empty space under my UIM is because there is no rat's nest (or Rat Box in case of my RHD version 5.)
The tuning shop that rebuilt my engine is called ForceFed Performance in Abbotsford B.C., The reliability mod build was pretty extreme in eliminating emissions and sequential turbos solenoid /acuum systems.
They had their own wiring specialist.
Seven years on I am slowly learning what all they did, haha.
47,000 km since my rebuild. I posted the compression numbers above.
Pretty pleased at this stage of engine life, but I was to complacent on the state of the remaining vacuum hoses.
It seems the vacuum line to my FPR was totally crumbling meaning the FPR was not being held open enough.
Hopefully my easy flooding issue is cured.
Also got my AFR sensor replaced and it is showing the car idling pretty lean.
So likely the tune is not too rich for low revs..
That big empty space under my UIM is because there is no rat's nest (or Rat Box in case of my RHD version 5.)
12-21-23, 02:23 AM
#114
Here is a recent discussion on Akagi's thread about the repositioning of the coils on later JDM versions.
https://www.rx7club.com/3rd-generati...1157199/page5/
https://www.rx7club.com/3rd-generati...1157199/page5/
12-21-23, 02:37 AM
#115
I don't know much about crank angle sensor. But I heard that the way they work, it might not matter that they are dirty.
Here is what a clean set looks like.
https://buyee.jp/item/yahoo/auction/...uggest_history
Here is what a clean set looks like.
https://buyee.jp/item/yahoo/auction/...uggest_history
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Xion (12-21-23)
12-21-23, 12:19 PM
#118
Full Member
Thread Starter
12-21-23, 12:23 PM
#119
Full Member
Thread Starter
In this picture I circled the same connectors I believe you did on the harness. The upper one is that yellow one and the lower blue circled one has a blue connector the plug went into. However, there is another plug left unused I will show you that looks very similar to the one you circled and possibly the issue?
this is the guy I’m talking about. I talked to wiring specialties and they said it was something related to later model FDs but maybe I got the plugs mixed up? I doubt it but worth an ask in case you know
12-21-23, 12:30 PM
#121
Full Member
Thread Starter
Also how much you guys think the injectors are just stuck closed? I had my injectors sent to be cleaned and got them back on October 6th. Seems like enough time for the cleaning solution to get them stuck no? Will pull UIM off today and perform click test
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Xion (12-21-23)
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Xion (12-21-23)
12-21-23, 02:04 PM
#125
Rotary Freak
Originally Posted by Xion
Billyboy, the place I sent my injectors to were injectorrx, they seem reputable no? Well I hope so.
Vaguely remember a mod and several others here, having issues with one of the aftermarket replacement harnesses some time ago though. That earth ring terminal near the ECU has been known to be missed on occasion too!