Acesanugal

iTrader: (5)

I've checked the FSM but it's a little confusing. What's the fuel pressure supposed to be at idle and what is it supposed to be at WOT? N/A 13b...S4

Having starting issues. Crank crank crank, no fire. Let it sit for a few minutes, try again...get a sputter but no dice. A few repeats of this and eventually it'll fire. It runs smoothly but it makes next to no power.

Cranking fuel pressure is around 32psi, but I've not been able to get her started again to get readings on the others.

Also, I'll be doing another compression test and see where it's at.

Oh, and the injectors have been professionally cleaned.

13bturbofc

iTrader: (4)

if you have pressure during cranking then i highly doubt your problem is due to fuel pressure

HAILERS

Like the FSM says:

With key On, engine OFF, yellow check connector jumpered: 37-39 psi.

Idle: approx 28 psi (I see 31-32 psi)

So if your starting your engine you'd expect to see 37-39 psi because the pump is running when the key is HELD to Start, and there's no vacuum to speak of to the FPR.

I've never looked at the pressure myself while Starting. I assume it'd be 37-39 psi.

I think at wide open throttle it'd be close to the 37-39 psi. Depends on what the vacuum is to the FPR during wide open throttle.

If I were you, I'd jumper the check connector with engine off, key ON and see how close to 37-39 psi you get. And if you ever get it to idle again, see how close you get to the 28 psi at idle.

EDIT: I thought about this a bit. If you cranking and cranking, the voltage will drop to the fuel pump. Soooo I'm guessing the pressure might actually drop a bit from the 37-39 psi to the figure your seeing. Normal I'd say to see the ?? 32 your seeing during Starting (but no actual start). I'd be a slight pain to do this on my car just to see what happens. I'd have to disable the ignition (duh, pull EGI)

arghx

iTrader: (3)

it doesn't seem low enough to be the cause of your problem.

does it start faster if you hit the gas a bit as it's about to sputter? Have any emissions or idle control systems been altered or removed?

Acesanugal

iTrader: (5)

When I crank the engine a few times, stop and let it sit for a few minutes then try again, sometimes it'll try and kick on - sputter - and if I catch the throttle just right she'll tumble into life. All emissions are still in place.

iceblue

32psi is the correct cranking pressure. Your car is flooded/flooding please review the FAQ on deflooding procedures pull your plugs and change them as well you are indicating a pore spark performance.

Acesanugal

iTrader: (5)

I've had the injectors professionally cleaned and blueprinted. They were and still are at peak efficiency. The spark plugs are new as of yesterday. I've done many a de-flooding procedures to no avail. I'm pretty sure all of this is the cause of low compression.

Back when I tested the compression with a fairly inaccurate gauge, it tested 75psi front, 65psi rear. My other car on the same tester was somewhere in the high 80s, and that car ran fine.

iceblue

Low compression will cause flooding.

How do you blue print injectors?????

Acesanugal

iTrader: (5)

You flow test them before and after cleaning, compare the data and come out with a percentage of improvement over the before and the percentage of variance between each one.

HAILERS

If it's a low compression problem/cause, the only thing you can do is use trickery to stop the flooding.

Either a fuel cut switch or depin a wire on the small ECU plug so the ECU never uses the internal fuel Start map, and uses only the afm for fuel.

An example would be the Start map making the injector stay open for 17ms during start, but if just the afm was used, the injector would stay open only 6ms. That would be pin 3B on a series four car. Try it out some day. Be sure to tape over the end of that wire if you do, because it'll have batt voltage on it anytime the key is put to Start.

Acesanugal

iTrader: (5)

Well, I finally used the new compression tester my friend made on the car. Front rotor is doing about 90psi and the rear is about 80psi. Which should be far more accurate than the old one he'd built.

The strangest thing happened, too. I put the battery back into the car, went to turn the key and it fired pretty much the second I touched it to 'start'. Which is...very random...considering it normally will just crank crank crank crank crank until you get pissed off and stop trying. I let it run for a bit to warm up, then turned it off...waited...tried starting it again to no avail.

Fuel pressure readings: Cranking, previous mentioned.
Idle, around 34psi
WOT, no change...if anything I thought I could see the needle drop ever so slightly...to the point where I didn't see it the first few times.

Who's got more ideas?

HAILERS

I forget. Does it start good when cold and difficult when hot?

Acesanugal

iTrader: (5)

Well honestly it doesn't start well period... But it's easier to start if the engine is still warm enough from running. When it's dead cold, it's at it's worst. When warm as I said, it will start but there's only a small window of maybe an hour or so before it cools off to the point where it's VERY difficult to get it restarted.

When it'll restart after it's been running, it takes quite a few cranks before it'll sputter to life.

HAILERS

Part of the problem MIGHT be the water thermo sensor on the back of the water pump housing. It's nothing but a resistor, but if one of the two pins in the connector is pushed back, that would make for a hard COLD start. Plug is green the last time I looked.

It's easier to tell by backprobing the green/white wire in pin 2I of the middle ECU harness. If the engine is cold it'll read approx 2vdc give or take a half volt. IF a pin on the connector is pushed back it'll read approx 5vdc, meaning the circuit is open and needs repair.

Acesanugal

iTrader: (5)

I'm wondering if maybe it's not just gummed up fuel filters. The car sat for a very long time before I got it. But you would think if that were the case, the fuel pressure would be lessened.

Acesanugal

iTrader: (5)

Hailers, I've installed a very simple fuel pump cutoff switch using the black wire with the white stripe coming off the fuel pump pigtail. Last night, I had the car running (idling) when I cut the wire and I let it die. Today I put the freshly recharged battery back into the car, switched the pump switch to on and started it...it fired right up on the second crank pulse or so. I will let the car sit over night and try starting it again tomorrow, switching the fuel pump to on before attempting to start. If that fails, I'll kill the pump, spin out the fuel to de-flood and get the starter going for a few seconds before flipping the pump back on. It's slightly more complicated, but oh well. If I can get the car to start reliably, I can further troubleshoot why it's making no power. Probably all three cats are gummed up. That's what I'm *hoping* for....

Acesanugal

iTrader: (5)

No dice this morning. It wouldn't start...so I left it, drove to autozone to buy a starter for my dad's truck, came back, went to start it and after a few cranks it fired. So basically when the motor is dead cold it just won't go, but if you let it sit for a bit and try again it will? Mind you, I killed the fuel pump and let it suck itself dry last night...

And of course now that I've got it running and the engine is up to temp I can kill the pump, let it die, and start it right back up again. The effect is shortlived though, until it cools down too much.

I do not have a multimeter at my disposal and cannot borrow or buy one right now... Is there another test to see whether or not the water thermo switch is good or bad/the problem? Like unplugging it maybe?


I did get to drive the car around my neighborhood for the first time in months though...it felt SO nice to be back in an FC again...it just sucks that it makes no power across the rev range and feels like it's gonna blow to pieces after about 4,000rpm. -sigh-

Acesanugal

iTrader: (5)

Update: Well, I decided to drop in another motor...a Mazda reman. I only bought a shortblock so it's using everything off the old motor....including the aux ports and water thermo sender.. allow me to continue.

While the motor was out I discovered some things... the motor mounts are in two pieces...so technically there's not anything ACTUALLY anchoring the engine to the car at all. That explains my very excessive engine vibration that shakes the whole car especially under full throttle as the revs build.

As it turns out, and I'm not entirely sure why I never checked this, the aux ports were not and do not actuate at all. They're not seized, and I cleaned them while I was swapping stuff over, but after doing the very simple (Yes, I'm hating myself) grease test...they're not budging.

Things only get worse... I discovered when I removed the wiring harness from the engine that one of the 'pins' for the water thermo sender was pushed back. I nudged it back into place and it seemed solid, but I'm not sure that stuck well enough.. This is a different sender from the new motor, obviously, but I'm not sure it's good...that or the pin has been pushed back again.

Replaced the fuel filter for good measure, and gutted all the cats (Which were awfully clogged), too.

Basically, the car has all the same problems it did before...what I thought was low compression (And the numbers hadn't been at all promising) really might not have been the issue at all. So, maybe some money was wasted... No power, won't start when cold but starts decent when warmed up..

I wired the aux. ports open (No, not permanently...considering the airpump activation mod as a permanent fix) and went for a drive. It could be my imagination but I think it might be less shy of the redline now and MAYBE it's got a little more up-top oomph.. The car was an automatic when I bought it, so even though it's manual now (With an S5 N/A gearbox) it's still got the 3.909 differential... It could very well be throwing off what I consider to be proper power for a stock N/A FC..

I'm doing a in-car compression test tomorrow...and may fool with the water thermo sensor and might try and borrow/buy a multimeter so I can test the sensor for within spec voltage or maybe not.. Bottom line: After all of this work I've put into the car since buying it, I've gotten such little enjoyment out of it that it's wearing on me. The car is gorgeous, though, and I'm just not sure I could let it go. It's the perfect color with the perfect interior and it's the trim level I want...it's just...perfect... but ******* hell it won't cooperate and run right to let me enjoy it! -Sigh-

Fawwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwk... .

jagass

I believe it's not the fuel pressure...

Acesanugal

iTrader: (5)

Of course it's not fuel pressure, we've already satisfied that. No real point in making a new thread though, so I thought I'd update it with the latest crap which surprisingly hasn't changed a bit.

HAILERS

The *won't start cold, starts when hot* is a problem with the water thermo sensor or it's wiring to the ECU.

If one of the contacts in the plug that connects to the sensor is pushed back, somehow make it NOT push back and make contact all the time. If the sensors output isn't seen by the ECU, the ECU defaults to a sensor input of 176*F. That results in a normal amount of fuel delivered during START when the engine is hot, but results in not enough fuel during a cold engine start.

The attached jpg explains how fuel is delivered during Start.

EDIT: Oh good. Going to get a meter. Put the meters negative lead on a known ground. Put the positive lead up the backside of pin 2I of the middle plug of the ECU with all plugs connected up. A cold engine will read somewhere b/t 2-3vdc. As the engine gets hot the reading will decline til it finally reads approx 1/2 volt dc (fully hot...180*F). Use a sewing needle/paper clip/equiv to shove up the backside of pin 2I so it makes contact with the contact, and then put your meters pos lead against the needle. OR ***** the green/white wire in pin 2I with the needle and place the meters pos lead against the needle to read the voltage.

A KNOWN gnd would be one of the studs on the ECU hold down bracket OR if you leave the ECU bolted down doing this, then use the case of the ECU itself for the gnd.

Gutted cats will cause not enough backpressure on a series four. Not enough backpressure to open the aux ports at the normal opening time is what I mean.

Acesanugal

iTrader: (5)

Hailers, I feel very bad for you. Throughout all the searching I've done I've probably been thru close to a hundred threads pertaining to my starting issues, and in every single one of them you've posted that same snippet of information about the water thermo sender... surely you're tired of it..

I'm not thrilled about peeling the carpet back again because of the valuable and fragile blue plastic fasteners I have to pop out to get the kick panel off, but I suppose it's necessary at this point.

After I test the water thermo sender or take another look at the plug or both, I'll update you again. I'm praying so hard that this sender is the cause of my cold starting issues... if I can get it to start reliably when cold I can be happy enough to not sell the damn thing. lol

Acesanugal

iTrader: (5)

jailers I'm not sure I completely understand how to use this multimeter, never had to before. Read over the manual and I think I've got it on the 200m DC volt setting. The readings were not consistent but it was around 0.03 to 0.08. Cold
Motor

Acesanugal

iTrader: (5)

Sorry, I made that last post from my phone earlier.... I've got an update going here..

So I went out and bought a multi-meter to test the sensor and I'm not sure I know how to use it properly. I set it on the volts, 200m. It was the only setting I could get a reading from...and it was between 0.03 to 0.08 with the engine cold. I tested it at the ECU...middle plug....green wire with the white stripe. I used a needle to wedge the pin to get contact and grounded it against one of the ECU cage studs having scratched some paint off to get a good ground. The readings were so erratic though, that's where my uncertainty comes in.

I also went around town and picked up things to make the modifications for the aux port actuators. Tapped into the airpump hose, aquarium valves to adjust things and routed it to the aux port air supply... After lots of fooling around, I STILL could not get the aux ports to budge. The actuators move very freely, more freely than my friend's working aux ports. The actuators appear to be in good working order...but no dice. I'm kind of wondering if the seal from the actuator to the LIM is good enough or if I need to pull them off and use some red RTV to guarantee a maintainable seal.

I also fooled with the Water Thermo Sender plug. Yes the pins push back but not enough to where they can't make a connection. There's no way they're NOT connecting, so the connection should be perfect.

At this point I'm ready to replace the sender with one from Mazdatrix as a last attempt. I'm getting zero enjoyment out of the car. Zero. I'm asking myself why I'm spending this money and putting in these hours of labor and getting absolutely nothing back from the car..

So, someone, anyone who knows what they're doing... tell me your thoughts... this car needs to run right very soon or I'm afraid I might let it go and try and find a car that already runs.

Acesanugal

iTrader: (5)

Got around to properly testing the water thermo sender at the ECU.

Cold, it was reading 2.15 volts which I watched drop as the car warmed up to N.O.T.
At Normal Operating Temperature it was 0.40 volts.

Sounds to me as if it's working properly?