Amur_

I had vac leak on my list at first, but I've seen had a good look around, and pulled and re-installed the manifolds (to get at the primaries.) Didn't find anything.

Talking to my mechanic friend in a chat right now. He has a good suggestion - put a teaspoon of fuel into each leading plug hole, put the plugs back in and crank her. **about finding dry plugs all the time --> "hmmm, then plugs should be wet if there is not combustion"

If she starts (or at least reacts to the fuel,) then that means that she isn't seeing fuel during cranking, which brings a whole new puzzle. Anyway, that's for tomorrow. I'm starving, food now!

lastphaseofthis

iTrader: (8)

How about puttin a jumper wire in the intial set connector like i already told you and assumed you tried.. at least see if your fuel pump is running, if it is and still no cranky, find the clog or replace the pump.

also it may seem like a stretch, but you can Verify if the CAS is turning when you crank the motor?

MazdaMike02

iTrader: (4)

Sounds like a fuel issue. My 7 would start only with ether, I swapped the primaries for known good injectors, no difference. I was getting proper fuel pressure...so I was puzzled. I changed the fuel pump just for ***** and giggles and that turned out to be it.

I would say pull or push start it. Verify you have sufficient pressure and hold pressure refer to FSM or haynes for specs.

Amur_

I did answer you, although I tested it in a different way. The fuel pump does send properly during cranking. I also checked my fuel cut-off switch and it is working properly as well.

https://www.rx7club.com/showpost.php...9&postcount=14


Sort of? I've established that the coils fire and the primary injectors fire when the CAS is spun. For the primaries, it was with the key ON and not a cranking situation. I've confirmed that:

- fuel pump operates during crank and key ON
- signal from CAS to ECU to coils is working during crank
- signal from CAS to ECU to coils is working key ON (could hear them during the primaries testing)
- signal from CAS to ECU to primaries is working key ON
- signal from CAS to ECU to primaries is not confirmed during crank

If the teaspoon of fuel gives positive results, I think the next step is troubleshooting between the CAS and the injectors. The only thing between the injectors and the chambers are the runners - I don't think there's anything in there that could possibly prevent fuel from reaching the chambers. Plus it would be an extraordinary coincidence if something in there did go fucko at almost the same moment as the rad failure.


There isn't room (nor traction) to push start it and no option right now to pull her. [edit] Also, push/pull starting won't accomplish anything if fuel isn't reaching the chamber. That question needs to be answered first.[/edit]

Pressure was verified during the primaries troubleshooting; a) by how quickly the jar filled with fuel during the brief cranking and b) when I first went to check the primaries/CAS, I keyed the car On without blocking off the fuel line to the secondaries (which I had disconnected to remove the manifolds.) Can you say fountain? And finally when the primaries were firing they were emitting proper cone jets. Lots of pressure.

RotaryEvolution

iTrader: (30)

you're gonna wind up with a car in pieces that has more problems than it originally should have had if you keep it up.

the car is probably flooded due to cranking it after the electrical issue of the radiator explosion. the coolant STILL needs to be cleaned out with water and compressed air and deflooding procedures followed, most likely i would suggest a few ounces of MMO in each leading plug hole and crank the engine over by hand a few times.

it's your car and your choice but i'm letting you know that i was serious. you can beat your head against the wall all you want but ripping things apart and looking for ghosts will just frustruate you more.

Amur_

Just as soon as I come up with a way to test parts that is based on standing back and staring at the engine instead of localized disassembly, I will change my technique.


You appear to have discounted (or overlooked?) everything I've recorded here. Flooded, with dry plugs? Without stinking of gas from either the engine bay nor the exhaust? That doesn't make sense to me. Plus I'm the one with his head under the hood. No one else is. Either you trust my posts to be honest or you don't. If you don't, why reply?


Maybe. The shutdown seems directly tied to the explosion. Whether that was caused by a component being disabled or destroyed remains to be learned. If something was rendered inoperative due to continuing exposure to coolant, I'll find it soon enough.

What I still won't do is dump water all over an engine bay in sub-zero temperatures, especially when there is no ready means of drying it afterwards. Call me crazy.


I'm partial to atf, but I'm all out of it and there's nothing wrong with 5w30.


I don't want Serious. Too dramatic. I'm fixing a car, not breaking up with my gf.


And here I thought I was troubleshooting components and systems and narrowing in on the source of my problem. You seem absolutely convinced of specific solutions despite the evidence against one and the infeasibility and potential destructiveness of the other. Whatever. I'm going to keep working on it in the way that makes the best sense to me. It's all I can do. You go on being a pillar of support in the way that makes the best sense to you.

RotaryEvolution

iTrader: (30)

no need to get defensive but i will say i probably do have a little more experience in the aspect of these cars and gave my best suggestions.

engine oil doesn't burn, it will foul the plugs. water does freeze, get it somewhere warm and with compressed air. dry plugs does NOT mean the engine can't be flooded, i'm sure you cranked the engine for a good 20 minutes after the issue, possibly with fuel being injected and no spark resulting in the seals becoming dry and unlubricated which results in low cranking compression on older engines and even new ones. gas does dry and leaves no trace that it was sopping in fuel only a few days prior.

i gave my idea, you can just disregard it if you want or argue why you think it's a bad idea. i understand your situation but sometimes you just can't fix something without finding a nice dry garage somewhere out of the elements.

Amur_

How would you react if, after 3 days of difficult but productive work, someone told you that you didn't know what you were doing? That was the bottom line of what you posted...


And I will say that my mechanic from the chat earlier probably has more experience with rotaries than you and I put together (and we're both making these statements while missing half the equation, rendering them both nearly meaningless,) and with the same information I posted here he didn't focus on flooding at all. His intuition has mirrored my own, without any coaching from me; I'm going to follow that avenue first.


You would be dead wrong. There's no point in wearing out a perfectly good starter for no reason. It's been cranked no more than a dozen times since that morning, and no cranking for longer than about 10 seconds. I didn't just get off the boat yesterday.


Change that to, "can't fix something as easily," and I'll agree with you. What I have to work with is what I have to work with. Declaring that someone is doomed to failure because they won't follow your favourite strategy is not at all helpful.

jjcobm

iTrader: (18)

I call flooded too but prove us wrong please, I can't think of anything else that would cause it to not start besides that bad coil you suggested

KhanArtisT

iTrader: (2)

What happened to just sticking the spark plug near a ground and observing for spark as the engine is cranked? That + the injector test with the manifolds off should guide you in the right direction. Sometimes biting the bullet and checking components with labor intensive methods is easier than guessing and getting frustrated because that can lead to you wanting to set the car on fire and other self destructive actions.

I haven't read the entire thread though (way too much reading for me personally).

RotaryEvolution

iTrader: (30)

prove us wrong.

spark>fuel>compression.

Amur_

That was one of the first things I did.


You may well be right. I won't know until this is all done.

lastphaseofthis

iTrader: (8)

The Flaw in your fuel pressure test is that it filled the jar when there was no "back pressure" on the pump. you need a guage installed between the pump and regulator, and observe the pressure while cranking, it should be in the 38-40 psi range. i could be off on the figures, recheck in the FSM. it's more cost benefitial at this point to just buy a pump instead of a guage set if you can't borrow one.

Another thing is try to get the car to run for 20 seconds on quickstart, maybe in the 20 seconds the fuel pump will come back to life and keep the car runnng, but i doubt it.

Simple truth is, if a car starts on quick start, but wont other wise, its NOT FLOODED. does it start every time you put quick start in it? or not?

another thing, how much fuel is in your tank? would it be possible for it to be bad, or were you driving the car daily prior to this? can you fill a clear bottle with the fuel and maybe post a pic, or get a good look at it in a large quantity.

Pele

iTrader: (28)

^ +1

I'd still lean towards fuel...

If she starts on starting spray, then the spark is good.
If she starts on starting spray, then the compression is good.
And if she starts on starting spray, then the CAS is in correctly to hit the spark at the right time.

KhanArtisT

iTrader: (2)

I realized that after it was too late to edit. If you saw the arc then the spark is not your problem. Connect your spare CAS, turn it 5 or so revolutions, try to start the car and then check the plugs for fuel.

And FYI you can rent a fuel pressure gauge set from Advance/Autozone for free.

RotaryEvolution

iTrader: (30)

i missed that it is starting on starting fluid so flooding is out, do a spray test on the injectors since you're this far and then do a pressure test on the pump, volume doesn't really mean much.

my new bet is on the AFM

ifryrice

It means it isn't seeing enough. Or the gas is terrible and doesn't want to ignite... But, that's not all too common. Starting on starter fluid isn't really a good indication that you have sufficient compression either, but it gives an idea that at least there's something.

You've already verified the injectors spray, so the only logical assumption (This is, of course, if compression isn't a problem) is that they're not spraying enough. So, you either have a fuel pressure issue (unlikely if the car ran fine up until stalling), injectors clogged (again, unlikely), thermosensor issue (possible...), ECU issue (unlikely), or the very highly likely event that unmetered air's screwing your cranking fuel ratio.

Put together cheap intake pressure tester and give that a whirl.

lastphaseofthis

iTrader: (8)

Thats what i thought also, but the pump runs, and the injectors ARE pulsing, and Spraying, he said he already pulled them out and tried that... i think although the pump is running and pushing fuel after resistance is entered in to the equation the pump is craping out, you maybe able to get away with a new fuel filter and new fuel sock... try try try.

RotaryRocket88

iTrader: (7)

I read through just about everything, but didn't see whether the fuel pump test connector was jumped during any of the cranking attempts (yellow 2-wire connector on shock tower). Any change in behavior if it's jumped?

If the AFM fuel pump switch is bad, then jumping the test connector will allow the pump to run. But another thing to consider is that the AFM fuel pump switch only comes into play when the key is released from the 'START' position and the engine has begun to idle. Start-up fuel delivery bypasses the AFM switch.

RotaryEvolution

iTrader: (30)

the pump can trigger and hold residual pressure and trick you into thinking that the switch is remaining on while doing on the car tests but during cranking that residual fuel pressure goes fairly quick.

there's just still something missing. a fuel pressure test would still answer a few questions as to whether there is fuel pressure remaining up while cranking. these cars have enough electrical issues that i never rule out anything that i have never seen before because they always tend to have a new problem everytime i look at one.

Amur_

Progress!

Finally got to her this afternoon. I managed to get a little gas into the L2 hole before my plastic vet syringe turned into garbage. I reconnected the AFM, put the plug back in, cranked her and she sputtered and tried to start. It was the only time she has done this other than when the Quick Start was used.

So there we go - she's starving for gas.

I don't have my own pressure tester. Might be able to grab one tomorrow. But...

The engine reacted quickly and strongly to the little bit of gas I put into the chamber (and some of that gas would have been tossed out the exhaust port before coming around to the plugs. She almost starts when there's almost no gas in there, plus the previously observed bone-dry plugs says to me that the injectors aren't firing at all during cranking. If they were firing like I observed them firing when I tested them the car would be running right now and we wouldn't be having this conversation. Even if the pressure was abysmally low, some gas would still be reaching the chamber and she would at least be sputtering during cranking.

And finally, it makes sense to me that the injectors are at fault and not the fuel system, since nothing of the fuel system other than hard and soft lines would have been in the line of fire of the explosion.

Reminder: I did establish earlier that the fuel pump is sending during normal cranking.

I think the next step is to determine if the primaries are firing during cranking. I'm thinking that the easiest way to do this is to backstab the ECU pinouts for the trigger wires and crank the car. Correct?





This has not been done. I'll head down now and do it, just to rule it out (or in. )

KhanArtisT

iTrader: (2)

Yes, backprobe one of the primaries with a jumper wire/miltimeter lead and then ground it repeatedly as you crank the engine (making sure not to ground it for too long at once). Even just one injector firing will be enough to get a reaction.

Amur_

I was picturing + probe to the pin and - probe to ground, crank and watch for 12v on the display. I'm not sure what you mean by "ground repeatedly." Will a constant grounding from the probes be either disruptive or damaging?

ifryrice

Didn't you already once verify that the injectors were firing when triggered? It doesn't seem likely they would've crapped the bed at the same time the radiator went out. If the mixture's lean enough, you likely won't end up with gas on the plugs. My guess is you're either lacking appropriate fuel pressure, or the ECU isn't injecting enough. If the injector wiring's intact, and all that happened was it overheated, I wouldn't really consider them a likely candidate.

Amur_

Yes, but it wasn't a cranking situation.


Perhaps not likely, but still possible. And it's a quick and simple check so why not quickly eliminate the question entirely?


What I've found says to me that *zero* fuel is entering the chamber. I inserted barely 2 cubic centimeters of fuel into the chamber. An online converter tells us that this is: 0.067 628 045 403 ounce. And that's before the loss to the exhaust sweep. In other words, the car nearly started with sweet ****-all for gas in the chamber. Sweet ****-all > nothing.


I don't see how at this point. That theory doesn't gel with my findings so far. I'll agree it's still possible, but it's been pushed back to my list of Super-Remote Explanations...


Ah, but if they're intact and part of them is immersed in a liquid like coolant, which goes back to Karack's previous assertions, then that might be a problem.

I'm closing in on this. Not much further to go, I hope.