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Drove it to work, drove it to lunch. Heading home and it didn't light. Engine turns over and I get a faint whiff of gas at the tailpipe but not even a hint of ignition. Being away from the garage and all my tools didn't help but at least it's a neighborhood where I'm not concerned about the car being abused. No indication of poor behavior during the drive to lunch which was definitely long enough for the engine to get to temp and receive at least one Italian Tune-Up. Having been away from rotaries for a decade has dulled the senses. What else can I look at?
What I've done:
checked for smell of gas at tailpipe
pulled FP relay, turn the engine over for a bit, reinstalled relay, try again
Swapped FP relay with A/C relay
I didn't have tools so I couldn't pull spark plugs but I'll be doing that in the morning.
Couldn't find the aftermarket ignition coil, will sort that in the morning. Note: any way I can test for spark?
I couldn't think of a way of testing the FP, possible it died in the parking lot?
What about factory ignition kill systems? I've pulled out an aftermarket alarm system and I believe I pulled out the headllight flasher for the factory alarm if memory serves correct because it kept triggering while sitting still all by itself in the garage.
I'm assuming the compression is good since it just drove. That leaves fuel and spark.
It doesn't sound like it would be flooded, though that is a possibility. I assume when you try and start the car the motor just turns over, it doesn't even try to fire or anything?
If it doesn't try and fire at all, I would suspect spark at that point. If you have spark but something is wrong with the fuel system you typically get SOME fuel going in there, enough so it tries to start or speeds up a bit.
If you have an aftermarket ignition box that's a definite place to start looking.
I have never been able to hear the pump run by bridging FP and GND like the FSM says. Please let me know if you find different.
From my personal FD experiences the first place I'd look is fuel. I recently had the tank bulkhead connector flake out and that caused a no start issue. Have since bypassed that pos connector and the steering column resistor (aka ignition switch).
You can easily tee a cheap gauge in under the intake elbow to see what the pressure is. I would recommend a permanent FP gauge so you can monitor. I was fortunate to catch mine before it caused any issues. AEM makes a decent loggable gauge for under $200.
I had something similar happen to me a couple months back.
My EGI relay somehow wasn't clicking on, so my fuel pump and other ignition components weren't working. (I simply pulled it off, put it back, then it starting clicking again.)
Can you not hear your fuel pump priming after a quick turn of the key?
I would also try to bridge the terminals for the fuel pump at the diag. block. (I too haven't been successful with that working, but I only tried when I was having relay issues, which would also explain that.)
I had something similar happen to me a couple months back.
My EGI relay somehow wasn't clicking on, so my fuel pump and other ignition components weren't working. (I simply pulled it off, put it back, then it starting clicking again.)
Can you not hear your fuel pump priming after a quick turn of the key?
I would also try to bridge the terminals for the fuel pump at the diag. block. (I too haven't been successful with that working, but I only tried when I was having relay issues, which would also explain that.)
I haven't heard a thing when turning the key. I'll get it towed home so I have access to my small set of tools but at least then it will be home. I'll verify 12V at the pump and see if I can get it to turn with direct stimulation from a known good 12V source.
So, I've confirmed power back to the pump bulkhead so the pump has officially died. I'm going to guess its probably the 25 year old electrical connector but there's no point in cracking open the tank without replacing the pump, right? I'll go ahead and get the bulkhead kit from Racetronix, if I can ever get them to take my money. Anything else I might as well do while I'm in the tank?
So, I've confirmed power back to the pump bulkhead so the pump has officially died. I'm going to guess its probably the 25 year old electrical connector but there's no point in cracking open the tank without replacing the pump, right? I'll go ahead and get the bulkhead kit from Racetronix, if I can ever get them to take my money. Anything else I might as well do while I'm in the tank?
As always, thanks in advance.
You could simply throw a walbro or a Supra pump in there with a nice new strainer and call it a day.
Obviously, check the voltage on the wiring through the connector to make sure it isn't simple stupid between the wiring.
One more tip... if you do remove the hat from the fuel tank, don't leave it sitting around for a week or longer... The rubber seal between the assembly and the tank likes to shrink, and may be difficult to line back up when re-assembling.
I've verified functional relays and continuity up to the bulkhead connector pigtail. With the key in On and pulsing the Main EGI fuse I verified voltage to the pigtail. A challenge single handed but with the wiring guide, some alligator clips and a test light it can be done.
I was already planning on ordering a new seal from Mazdacomp, assuming I can get one. They're reasonably good on new old stock it seems. At least I'll be starting there, because Mazda parts.
This whole exercise has me thinking about the kinds of instrumentation that would be handy. FP voltage would be nice to know, a pair of idiot lights for low and high voltage would work here. Oil pressure, fuel pressure, coolant temp. Boost and wideband O2 I already have. The rest would be handy diagnostic tools that I wouldn't mind having full-time. I may see if someone has a PIC-based project that provides that kind of feedback. I may just build my own if I don't find something to ride the coat tails of.
This whole exercise has me thinking about the kinds of instrumentation that would be handy. FP voltage would be nice to know, a pair of idiot lights for low and high voltage would work here. Oil pressure, fuel pressure, coolant temp. Boost and wideband O2 I already have. The rest would be handy diagnostic tools that I wouldn't mind having full-time. I may see if someone has a PIC-based project that provides that kind of feedback. I may just build my own if I don't find something to ride the coat tails of.
Believe the newer ECUs let you sensor most anything and with benefit of controlling the engine vs. simple displaying/logging values. If you are running a stock ECU or PFC, you can get a multi-gauge like PLX. I installed a 14point7 that i really like, but alas, it's NLA. They still make a tablet/phone interface though: https://www.14point7.com/products/idash
I've seen a couple things like that but I'm thinking more along the lines of something I can glance at while on a straight on-track. PLX stuff is pretty nice. I could see that going where the soon-to-be-removed stereo now lives.
I finally had time to work on the car this morning. I verified that everything was still non-op before I turned the first screw, just on the off chance. I disconnected power and removed the pump hanger and the pump from the hanger. Then I tested the pump directly to the battery. Lo and behold, it ran. I'm going to bet that some bit of banging it around freed it enough to run. Put everything back together. Prime the pump by cycling power a few times. Car starts right up. Drove it for about 40 minutes after full warm-up in the driveway. No problems what so ever.
At this point I'll call it functional but "ready to fail again any time". I will replace it correctly but probably not until the winter. I did get to verify the pump part number and it is a Denso 195310-1270, not the -1020. What I'd like to do is get another pump hanger and build it up to handle a different pump with electrical connectors that are able to handle more current.
This all said, I'm going to have to source another hanger. I've already got the Racetronix bulkhead connector so I will likely use that though I have no discoloration or distortion in the factory connectors. Unless of course the wise folks here tell me I'm being daft.
I'd also like to solicit suggestions on pumps. I know Walbro has a poor reputation. It also seems that Walbro pumps are rebranded by several different resellers. I may be *completely* off base here but Walbro, Racetronix and Airtex all have suspiciously similar specs and mechanical design. I will of course defer to the smarter folks.
Knowing you have a flaky fuel system I'd be terrified of losing fuel pressure and leaning the engine out under boost. With no AFR or fuel pressure gauge there is no way of knowing how close it is coming to catastrophe.
Definitely bypass the stock bulkhead connector. In my experience I had to completely disconnect the bulkhead connections to see that they had developed a problem between the contacts. The failure was not apparent even with the FP assembly out, but the contacts had eroded and the heat generated started to melt the plastic a bit.
I've been happy with my Aeromotive stealth 340. Unlike impeller style Denso pumps that wear out, the stealth is turbine based. Logging my fuel pressure under boost shows pressure rising in lock-step with boost.
The denso pump will be a bit easier to install.
Either way make sure to replace the cheesy stock fuel pump rubber/plastic attachment with 30R10 submersible hose.
08-24-18, 06:55 AM
