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I was able to get the key turned for me with the scope directly on the orange plastic of the front injector, and I could not hear even the slightest ticking of any sort, but could clearly hear all the other noises of cranking coming through the scope. I think I got the rear injector too, but couldn't actually see it from above or the side. No sound there either.
Going to be removing the dynamic chamber/UIM now. I assume the gasket I need is N304-13-114A ?
Once I get the UIM off, to test the injector wiring/pulses, can I just wire in a 12v LED just like how I did with the ECU diagnostic port?
Also, I was on the Mazdatrix website and found an "Injector inlet filter" https://mazdatrix.com/product/inj-in...92-inj-filter/
Is this something my car has, or is this an upgrade that Mazdatrix sells, and should I get them?
It took me about two hours to remove the dynamic chamber and the injectors.
Problem found.
Both injectors are completely clogged with reddish-brown goo and particulates.
One of the injectors I cleaned off the top before taking pictures. The other I did not.
Course of action: Test injector wiring still, its probably fine.
Get injectors sent off for cleaning, or just buy a pair of used ones right now and send these off to be cleaned and kept as spares.
New fuel filter.
Possibly new fuel pump.
Get gas tank checked, cleaned, and relined if necessary.
Is it safe to send an inspection camera down the fuel filler neck, or is that risking an explosion?
Might want to also check your tank. Just run the fuel pump into a bucket.
I drained the entire tank using the fuel pump already, and the gas that came out was stale with a small amount of dirty water at the bottom of the first gas can I filled up (I drained out about 11 or 12 gallons) The dirty water that came out didn't have any chunks in it, but that must still have been enough to clog the injectors. Time for a tank inspection for sure though.
I've never seen those Injector Inlet Screens before. I wouldn't buy them, but I would recommend buying 2 sets of these (*pintle caps - the spraying end, and lower grommets where the Injectors mount to the engine center housing);
Who knows how long these parts will still be available from Mazda, and when you find replacement Injectors, you may need these parts to recondition them. Whatever you find, I highly recommend sending them to a Fuel Injector repair facility to get them cleaned up, flow tested and spray pattern balanced. Since the Series3 intake only uses 2 Injectors - one for each rotor - it's critical that you get a good, matched spray pattern for best performance.
You're onto the root cause of the fuel tank needing work. That you removed rusty water from the tank is a good sign that maybe the fuel pump sent some water up front which caused the rust issue at the Injectors. Regardless, since the pump is running fine, I'd remove the Fuel Injection Hose from the inlet on the pump and check the wire screen filter there for rust and sediment. Then, replace the metal, high pressure Fuel Filter while you're under there, and lastly, flush the Feed and Return lines to be sure you got it all. The Fuel Pump is probably fine, they last nearly forever (*and are $345 last time I bought a spare...).
In the meantime, also inspect the Injector pigtails for damage and replace, if needed. Otherwise, I'm about 99% confident that once you get it all buttoned up again, it should start right up. Let us know how it goes,
I'll be sending my injectors in to be cleaned and tested.
As for the injector inlet screens, it looks like the injectors have them inside already, and they can be replaced, according to Atkins: https://www.atkinsrotary.com/84-92-r...n-are964-.html
I think RC says they replace these as well when you get a cleaning done.
I've ordered a set of grommets and pintle caps, and I've also sent an email to RC asking if they can replace these if I send them in with the injectors.
My fuel pump has always sounded a bit 'off' with varying tones and pitches, like a failing computer fan, and who knows how long you will be able to buy fuel pumps at all, so I went ahead and ordered a new fuel pump along with the gaskets that go on the fuel tank for the pickup lines and level sensors, since the tank will need to be removed, opened, and cleaned anyway.
Here is a video with sound of the pump running: https://streamable.com/x0z6ij
Question about replacing the fuel pump and fuel filter - Do I need to get fuel line pinch off tools, or will only a small amount of gasoline come out when I pop these lines off?
Another question: For replacing the pigtails, all I need to do is cut the factory pigtail off the harness and splice in the new ones? One of my two pigtails broke one of the clips on the side off. These things are incredibly brittle after 40 years.
Third question: Should I add anything to the gas in the future to reduce the risk of this happening again. Sta-Bil is okay to use, right? What about any sort of pre-mix oil or other common 'fuel system cleaners'.
When you send the Injectors in, include the Pintle Caps with a note to use your parts. The rebuilders replace a lot of things, and the caps may or may not be included if they don't have them in the parts bin. Keep the grommets with you; these fit over the spray end of the Injector and seal the bottom of the Injector to the center housing, and would probably get lost along the way as they're not an Injector part, per se. There are also matching O-rings at the tops of the Injectors that seal to the fuel rail - these are typically replaced by the rebuilders.
On Fuel Pump, that pump doesn't sound bad, but it doesn't sound good, either. I'd keep the original one in the parts bin as a backup, since you ordered a new pump anyway. Fuel Pump replacement is easiest with the back of the car on Jack stands, crawling in from behind and once you remove the protective cover plate, it's straight-forward. The Fuel Injection Hose MUST be high pressure rated hose from the pump forward. You can't use standard fuel hose, as it will expand too much and burst. Fuel feed to the pump is easily accessible, but note that as long as there's fuel in the tank, its going to want to run out when you detach it. For this reason, empty the tank first with the drain bolt on the bottom. This will also help you remove sediment and rust from the tank. Once you catch it, screen it to see how bad the internal fuel tank rust might be. This should help you decide how you want to handle correcting it.
I mentioned this before, but you definitely need to replace the N304- FI Fuel Filter under there, as well. With the pics you shared above, your Fuel Filter is likely clogged up, and could be part of the noise you hear back there. Buy 2, so you'll have a spare, just in case anything else is still in the system and it gets flushed back into the tank.
Fuel Injector pigtails are available from Borg-Warner last I checked, and as long as you splice them in with solder and heat shrink tubing, taking note of the polarity of the original wiring, it's an easy fix. Also be mindful ofmthe spring steel clips that hold the connectors onto the Injectors so you can remove them in the future without damaging them. At 40yo, every plastic thing on these cars is brittle and fragile.
I don't use fuel additives, though some of you guys who store your cars may have better suggestions. My SE gets driven occasionally year-round, so I'm constantly cycling fresh gas into it. In the aviation world, you always store aircraft with full fuel tanks to limit the air gap, which allows moist air to corrode tanks and fittings. That might work if the car will sit for months to years. Around here, we get oxygenated fuels which are hard on fuel systems of this era - but it seems that either draining completely or cycling frequently has kept my car running well.
Can't wait to see the video of your startup once you get it all back together. Nice work sorting out the various systems to find the culprit. I knew once you got a stethescope on those Injectors, it would tell the tale. Report back,
Sidenote; while the Injectors are out for service, do you have the gumption to remove the LIM and clean the 6-port sleeves? It's only an over 6×12mm bolts and nuts, a LIM to engine gasket, and a time-consuming de-carboning of everything around and inside the sleeves. Something to consider if you have the time and inclination, but be aware that it miht open up to become a lot more work if you have broken crispy rubber seals or stuck rotary valve sleeves. Quick test: how easy is it to rotate the 6-port actuator rods? You should be able to rotate the bellcrank on each one by hand, but with resistance. It should hurt your thumb, but rotate about 100deg (*CCW for the rear port, and CW for the front port actuator).
I just got a set of 4 injectors cleaned by RC just last month, they included all NEW pintle caps and new grommets (top and bottom) when they were returned back to me. (didnt have to buy any from Mazdatrix)
( My only problem was that 1 out of the 4 came back still closed, and I picked the closed one to install 1st try, which furthered the frustrations...)
I fully intend to change the fuel filter before running the car, so that this doesn't happen again right away. I'll hold onto the new fuel pump until after I get the tank cleaned and lined, install the new pump, and probably change the filter again some time after that just in case.
As for the things on the LIM, I was not able to push them by hand, but I didn't push too hard as it felt like I was about to cut myself on them. The rods coming out of the round actuator things are clean compared to everything else around them, indicating to me that they do still open and close. I'm not feeling super adventurous with all the fuel system work still ahead of me, so I'll probably skip trying to clean anything in the LIM.
Your 6-port Actuators look good; I'd leave them alone, too. Let us know when your injectors come back, as I'm curious what the replacements rate as far as fuel flow and spray pattern. These things don't last forever, and buying a few known quality parts now buys years of driving down the road. Take care,
i think you've covered a lot of ground in troubleshooting the issue. Since the spark plugs remain dry even after verifying the spark and fuel pressure, it's possible that the injectors may not be injecting fuel. you can remove the injectors and manually apply power to them to see if they spray fuel.
Just an update, the injectors were sent off for service and should be arriving back in about a week. I've got the rear lifted up and the fuel filter bracket loose, but ran out of time so didn't finish the filter swap just yet.
I should have labeled all the bolts I removed from the UIM as well as I've forgotten which ones go where, but at least I took pictures during the disassembly to compare against.
Fuel Filter is a 17mm wrench for the banjo bolts and 19mm wrench for the filter to hold it stable when removing and installing the fuel lines. Might want to give it some time to depressurize (*if you've run the pump recently) or you'll get spray mist when you loosen the connections. Wear safety glasses.
Note also that there are copper crush washers on both sides of the banjo bolts, inlet and outlet, which can be reused as long as you don't drop them and lose them. Good luck, and can't wait to hear it running again soon,
New fuel filter installed. The old filter had a film of rust on both the inlet and outlets. I cleaned the fuel lines and bolts before installing them, and used the new crush washers that came with the filter from Atkins.
Any idea why the old filter failed to filter out the rust coming from the tank? Does it bypass once too clogged?
The good news is that the fresh gas that dripped out when removing was perfectly clean and clear, not the slightest tint of rust to it. Hopefully I should be able to at least drive it a bit to get the tank cleaned and sealed.
Nice work. The Fuel Filters DO NOT bypass when clogged. They tend to build up crap over time and even though there's plenty of filter volume, once they fill up with enough garbage, they restrict fuel pressure, which results in poor volume and spray pattern at the Fuel Injectors which results in poor performance. Since this is a gradual process over a period of years, I recommend SE owners change Fuel Filters about every 5-7 years if you're driving it regularly; more often if it sits for long periods, you have poor quality fuel in your area, or if your Fuel Tank is eroding.
To answer your question about the rust; my theory is that you had water in the fuel tank that went through the Fuel Pump, through the Fuel Filter, and that water was sitting in your Fuel Rail and Injectors for a few weeks to months, rusting the internals of the Injectors. The Fuel Filter doesn't care what liquid goes through it, and is only a sediment filter. This belief is supported by your observation that the fuel which came out of the tank showed no signs of rust. Water mixes with alcohol impregnated gasoline (*aka oxygenated gas), and it may have been drained out when you did your troubleshooting - as water is more dense than gasoline and settles to the bottom.
The first sign of Fuel Filter restriction is that the car will accelerate poorly above 3k RPM, and power will drop out suddenly at 4k RPM and cause jerking behavior at anything higher than that as the fuel pressure fluctuates at the rail. Usually, the car won't be able to accelerate in 4th gear at highway speeds due to reduced fuel volume and pressure and will barely hold speed, much less accelerate, when you floor it.
For the $57 cost of a new N304- Fuel Filter, I always keep a few in my box of spares, as they're cheap insurance. Going from a clogged filter to a new one feels like adding 50hp in 4th gear on the freeway When you step on it, it goes!
Nice work. The Fuel Filters DO NOT bypass when clogged. They tend to build up crap over time and even though there's plenty of filter volume, once they fill up with enough garbage, they restrict fuel pressure, which results in poor volume and spray pattern at the Fuel Injectors which results in poor performance. Since this is a gradual process over a period of years, I recommend SE owners change Fuel Filters about every 5-7 years if you're driving it regularly; more often if it sits for long periods, you have poor quality fuel in your area, or if your Fuel Tank is eroding.
To answer your question about the rust; my theory is that you had water in the fuel tank that went through the Fuel Pump, through the Fuel Filter, and that water was sitting in your Fuel Rail and Injectors for a few weeks to months, rusting the internals of the Injectors. The Fuel Filter doesn't care what liquid goes through it, and is only a sediment filter. This belief is supported by your observation that the fuel which came out of the tank showed no signs of rust. Water mixes with alcohol impregnated gasoline (*aka oxygenated gas), and it may have been drained out when you did your troubleshooting - as water is more dense than gasoline and settles to the bottom.
The first sign of Fuel Filter restriction is that the car will accelerate poorly above 3k RPM, and power will drop out suddenly at 4k RPM and cause jerking behavior at anything higher than that as the fuel pressure fluctuates at the rail. Usually, the car won't be able to accelerate in 4th gear at highway speeds due to reduced fuel volume and pressure and will barely hold speed, much less accelerate, when you floor it.
For the $57 cost of a new N304- Fuel Filter, I always keep a few in my box of spares, as they're cheap insurance. Going from a clogged filter to a new one feels like adding 50hp in 4th gear on the freeway When you step on it, it goes!
I have a tank with rust , not horribly rusted mind you, just 40 year old surface rust. After 12-14 months I start to get that 3-4k Hesitation. If you let the car sit long enough , the rust settles and causes major blockage. Since I have bought my car 7 years ago , I have gone through 5 gas filters. I always change them in pairs because the top filter starts to yellow and fatigue due to engine heat.
The only real fix is dropping and cleaning the gas tank.
The filter screen that arrived is not the same as the one in the photos from the other thread. The photo on the site did indeed look different from the one in the other thread, but I hoped it would at least be the same size. The part appears to have been discontinued, and replaced with a different design that supersedes multiple previous filter screens from Jaguar. The filter screen I got appears much smaller than the original part, with far less mesh surface area. Do you think that this filter screen will do the job? JagBits says that it replaces the older part, so if it is good enough for the Jaguar fuel pickup, perhaps it is good enough for an RX-7 fuel volume as well. The mesh does not appear to be as fine as the others, either.
If anyone has a better part to use for replacing the GSL-SE fuel pickup filter screen, please let me know. I want to use the best part possible for this.
What matters is the flow rate; did you read anything in the paperwork about max flow rate or similar? I would think it'll work fine, as most of the vintage Jags would be V6, V8 and V12, and well above what our 2 tiny (680cc nominal) injectors require.
Plus, keep in mind that the Fuel Pump inlet hose is larger than the others because it's low-pressure. This gives a lot of volume to the pump, which then converts it into lower volume, higher pressure. Your filter is doing the fine filtering, and is located after the pump.
The old gasket had hardened into Stalinium and required substantial effort with multiple fresh razor blades and multiple soaks in Permatex gasket remover.
After cleaning off the old gasket from the UIM (Took multiple hours) I got it put back together and everything reconnected.
The car started after about 15 seconds of cranking, and immediately idled up to just over 3k.
Bad news: After starting, it stayed at 3k for a long time, then idled down and the idle started bouncing up and down around 1500. I've triple checked for loose hoses and connectors, and there is slack in both the throttle cable and cruise control cable.
Could a small leak at the new gasket between the UIM and LIM cause this? I cleaned both pretty well, especially so on the UIM. I didn't use any harsh abrasive that could have harmed the metal, but I did get a few tiny nicks into it with the razor blade, didn't seem like anything that would cause problems, especially not this much of one.
Your 2nd video tells me everything I need to know; that's called "surging". Search on my name and that term and there are copious threads on what it is and how to fix it.
Here's what I think happened; your Fuel Injectors are now operating to spec. Over the years, you (*or someone) may have been making small adjustments to the Air Bleed Screw, the TPS, etc. to keep the idle steady as things deteriorated. Now that the culprit has been corrected (clogged Fuel Injectors), you're going to need to invest some time in getting everything back to normal again. The surging issues can be caused by many things, but usually - and with the age of our cars - it's due to galling between the aluminum throttle body and the steel throttle rods. This creates a feedback loop between incoming air, the TPS, and the Air Bleed system, sometimes also affected by the BACV getting in on the action if you have the A/C on or other electrical loads. Search and you shall find!
Also, I wouldn't worry about your UIM gasket install being the source of a vacuum leak. These aren't that big of gaskets and it's a straight forward install. Im sure its sealing just fine. Before you start taking things apart again, though - take a close look at your rubber vacuum hoses at the Dynamic Chamber. There are 4 at the front PS edge that go to the air distribution spider, 2 at the back PS edge that go to the Air Control Valve above the exhaust on the LIM, and then 2 more at the DS on and under the BACV that are easily forgotten, because they're hard to see. If every vacuum port is attached, then start in on fixing the surging.
If you get lost, post back, and Ill walk you through it first-hand. You've come so far, I feel like I owe you that! Great videos, by the way. I wish everyone could do that,...
Thanks for the info! I distinctly remembered only connecting one vacuum hose on the driver's side of the UIM. I forgot to connect the line that goes to the brass colored cylinder device mounted to the driver's side of the UIM.
Connecting this hose instantly solved the idle issue.
Image of the hose in question that looked connected at a glance but was not!
Side note, but still related to the fuel system - When I backed into my garage, I noticed a high pitched whistling sound coming from the gas cap. After turning the engine off, I slowly opened the gas cap, and a lot of pressure came out. More than I've ever experience when opening any gas cap. I could hear the gas tank popping back into shape as the pressure was released. This is also the lowest I've ever run the gas tank in the car, the gas light came on as I was pulling back into the driveway. Is this amount of pressure normal? Is it caused by the new (Genuine Mazda) gas cap I just installed? The new cap looks different from the old one, and lacks the plastic thing in the center of the cap. This is the first time I've driven the car with this cap.
Okay, great to see the car running so well. Your brights are on, btw. On the Fuel Cap, the new one you have is unvented and relies on the Charcoal Canister to purge the system. The old gas cap had a vent built into it. It's most likely that the vacuum lines between the Fuel Tank and the Charcoal Canister may be clogged. These are easy to check by disconnecting at the Charcoal Canister and attempting 5o blow air through them. There is a Vent Solenoid against the firewall that's supposed to open when the Throttle reaches above 2,500 RPM or so to suck the gas fumes stored in the Charcoal Canister into the intake to be burned. If you remove that hose and sniff around the Canister, you may smell the scent of gas, which is somewhat normal.
Emissions testing in my home state fails the car with an unvented gas cap, and it has to be manually passed by visual inspection for me to get new tags. Regardless, the only other vent is located at the "Roll-Over" valve under the car, between the tank and Fuel Filter which can also become clogged and prevent air passage. These rarely go bad, though. It's a beige plastic cylinder which has a few small vacuum lines going to it.
I'm also betting that if you fill the tank more fully, it won't build or retain much pressure, as there will be less air volume in the tank. If it doesn't bother you, I'd just fill it up and drive it. Nice work!
P.S. - that vacuum hose you missed goes to the Idle Compensator at the front of the BACV. It bumps up idle speed when electrical or power steering pump loads slow the idle speed, and it's controlled by the Air Solenoid located directly below it (*the 2nd from the left).
The brights are intentional, no one else was on the road and the headlights on this thing are so awful no one would noticed they were on even if there had been someone. I need to do an H4 upgrade.
I'll just switch back to my old fuel cap, I don't want my gas tank reenacting an East Palestine railroad tank car. I was able to blow air through the smaller hose on the charcoal canister that goes to the fuel tank. I was also able to blow air through the larger hose that seems to lead to near the oil filler neck. When blowing through this one, I could hear some valve opening after pressure built, and releasing the pressure. The service manual says the check and cut valve (I assume the thing you're calling the roll-over valve) should open at no more than 1psi, and it certainly felt like there was more than 1psi inside the gas tank.
Thanks for all the help! You're an encyclopedia of knowledge and your effort does not go unappreciated. Not sure I could have worked up the courage to take apart the intake manifold and fuel rail to fix this myself without help. Good to know that there are people out there with the knowledge and a willingness to help keep these increasingly obscure cars on the road.
This thread should be pretty much done, I just need to drop the gas tank and inspect it, clean and reseal if necessary. Removing the gas tank is another seemingly daunting task, but I suppose it really shouldn't be that bad. I'm just afraid of damaging any extremely rare connectors or bits in the process. Not sure if I'll get to that soon or not. I need to do it before more rust breaks free and clogs the fuel system up again.
02-15-24, 12:16 PM
