Why Wont This Effing Thing Start!?

[84Toyota4x4]

Ok, so not truck related at all, but my daily driver. The damn thing sputtered and died while driving home the other night, and my investigation revealed the fuel pump wasn't working (couldn't hear it running ever, voltage at pump connection). So, I bought a new pump, put it in, and guess what? Pump works now, but no start.

Ever since then, Ive been trying to figure out what in the **** is wrong with this thing. Its a 1995 Ford Aspire (gay car, but good on gas!), 1.3 liter 5 speed. So far, this is what I know:

- Turns over just fine with starter, no sputters or even an attempt to start

- 40 PSI fuel pressure at the fuel rail

- 180+ PSI compression on all 4 cylinders

- Spark at all 4 plug wires as verified by timing light pickup, inline spark checker, as well as physically pulling each plug and watching the spark.

- Timing is set correctly (electronic advance, mechanical is correct)

- After numerous failed starting attempts, plugs are wet. This obviously isn't good, but to me, it implies the injectors are working and putting gas in the cylinders. I dont have a noid light set, but I figure this kinda proves they work.

- Ive tried a different AFM on the air box, as well as a different throttle body with a different TPS. No change.

- All tune up parts are new within the last year. Plugs, wires, cap, rotor, O2 sensor, fuel filter, air filter.

I need ideas. Someone, please save me from taking my new oxy torch set to this car

~T.J.

 

[4xjunkie]

- 45 PSI fuel pressure at the fuel rail.

Well first spec is 25-31 psi, next make sure your ECT sensor isn't open circut, that will dump way to much fuel to start.

Find the fuel pump fuse, pull it, try to start, ( you may have to dry the plugs first), and you might have to crank a little, and you might have to insert the the fuse and remove a couple of times to get it to start.

 

[boxboy]

I think there is a fuel pump relay under the dash (a couple of them up under there) you should find the one for the fuel pump and test it... maybe swap them around if they are all the same (I don't remeber)

But I say it is the fuel pump relay...

 

[84Toyota4x4]

Well first spec is 25-31 psi, next make sure your ECT sensor isn't open circut, that will dump way to much fuel to start.

Find the fuel pump fuse, pull it, try to start, ( you may have to dry the plugs first), and you might have to crank a little, and you might have to insert the the fuse and remove a couple of times to get it to start.

The spec I have says 30-38. Also, I just double checked the gauge, and it was actually reading 40 PSI.

Ive tried deflooding numerous times by just unplugging the fuel pump (its still not put all the way together from replacement), and cleaning and drying the plugs. No change. Also, Im pretty sure the relay is good. The pump runs while cranking, and for a second or so after cranking stops.

Interesting you mention the ECT sensor. The temp gauge wire on my car is broken off and just kinda half hanging on there (temp gauge works though), would that be the same wire, or is it a separate sensor? If not, it makes me wonder where the other ECT sensor is to check that out. I never even thought of that, thanks!

I think Im gonna pick up some new plugs for it tomorrow and give that a shot just for fun since they're cheap and these have been soaked in gas so many times.

~T.J.

EDIT: Found the ECT sensor and the specs for it. Ill check that out.

 

[84Toyota4x4]

Update.

Checked the ECT sensor, and it appears to be within spec. The manual only gives resistance values for -4 degrees, 68 degrees, and 176 degrees. The resistance at 68 degrees is supposed to be 2.2 - 2.7 Ohms. I was getting about 5 Ohms at 38 degrees ambient temp outside, and since the resistance goes UP as the temp goes DOWN, it seems to coincide with the values. Since the engine wont start, I obviously cant verify it to be working correctly when warm short of pulling it out and putting it in hot water, which I didnt want to get into (draining coolant).

I then checked the coil input voltage, it was in spec. The coil resistance for the primary and secondary circuits are also both in spec.

The camshaft sensor input voltage is in spec, as is the sensor voltage range when the distributor is rotating.

I then moved onto the crankshaft sensor. This is where Im thinking I might be having a little bit of a problem. The input voltage is in spec, however, it says that while the distributor is rotating, the sensor voltage should "fluctuate between approximately 0 and 5 volts". Well, I was getting 0 to about 3 volts consistently, and 0 to 5 volts occasionally.

When the camshaft sensor was tested in the same fashion, it was supposed to fluctuate between 5 volts and less than 1 volt. I was consistently getting 5 down to 0.15 volts while rotating.

I'm wondering if my problem lies in the crankshaft sensor, since the voltage values aren't quite following the specification. Although, it does say between approximately 0 and 5 volts. So who's to define what approximate is? Within 2 volts good enough?

It follows up with a further test to verify voltage on another wire if the voltages aren't within specification. I went ahead and did this, and mine passed. This places the "fault" in the crankshaft sensor itself, and not in the wiring or the ECU.

My main concern, is that this effing car has all the above items built into one super expensive distributor so I cant just replace one of the items. I obviously dont want to slam the money down ($300 or so) for a distributor in a $500 car then have it still not run, so Id like to be very certain of whats wrong first...

~T.J.

EDIT: New plugs also made no change.

 

[4xjunkie]

Are you using a DMM or labscope to test CMP and CKP?

 

[4xjunkie]

So who's to define what approximate is? Within 2 volts good enough?

If you have a differance of about .2-.3volts, 2 volts is off the scale, as far as being close.

You have a 5 V ref, and you lose 2V, that means you lost 40% of the signal.

If it does not reach at least 4.75V, then the ECM will not identify the signal, the same also goes if it does not pull down to at least .25V, the ECM will not identify the signal. The ECM only sees OFF or ON, nothing inbetween.

Now is your CKP a actual postion sensor or just a TDC sensor.

A TDC sensor will only have one signal per rev

 

[84Toyota4x4]

Are you using a DMM or labscope to test CMP and CKP?

DMM, and a cheap one at that.

If you have a differance of about .2-.3volts, 2 volts is off the scale, as far as being close.

You have a 5 V ref, and you lose 2V, that means you lost 40% of the signal.

If it does not reach at least 4.75V, then the ECM will not identify the signal, the same also goes if it does not pull down to at least .25V, the ECM will not identify the signal. The ECM only sees OFF or ON, nothing inbetween.

Now is your CKP a actual postion sensor or just a TDC sensor.

A TDC sensor will only have one signal per rev

Good point about signal loss. However, Im confused. Why would I still have good strong spark, and the timing still shows to be correct with the light, if the CKP sensor is bad?

I dont know the specifics of the sensor, only that its built into the distributor along with the CMP sensor, coil, blah blah gay car.

Thanks for the help though, anything else you can offer would be great. Im thinking about trying to track down a junk yard dizzy or two to swap in and see if that fixes it.

~T.J.

 

[GaryTJ]

It sounds like you have the basics covered as well as you can without proper tools.

I am thinking weak spark at this point. Put it all back together and have someone try and pullstart you. Key on, gas pedal to the floor. (clearflood mode)

we have to that all the time on Honda's.

 

[84Toyota4x4]

I was thinking weak spark as well since I noticed that with the timing light, I can only get the pickup to work if its close to the distributor cap. It wont flash if the pickup is in the middle or anywhere more towards the plug end of the wire. Ive never noticed this before with other cars, but who knows, maybe its common?

On that same note however, with the plugs out and grounded while cranking, I get a consistent bright blue spark from them, it doesn't appear to be a weak spark at all.

Another strange note. After performing the compression test, the motor did in fact start. I confirmed it had compression and said "fawk it, Im gonna try starting it again". Hoped in, hit the key and it fired right up. I assumed from the compression test basically deflooding it. I backed it up back onto the driveway, and let it idle for about 30 minutes to thaw the windows and the snow while I put all my tools away. As soon as I was done with that, I hoped in and went to take it for a test drive. I then promptly killed the car trying to use the clutch (been driving the 4Runner for a while), and it has never started again even after attempting to simulate the scenario (deflooding, more compression testing, etc) I fawking hate this car.

~T.J.

 

[Binder]

If it were mine I would hit it with some starting fluid and try to start........


I'll give you $500 for it.:awesomework:

 

[CrustyJeep]

Our Jeep pulled that **** recently. Wouldn't start cold after sitting all week, just wet plugs. Lean it out by disconnecting one injector (TBI), fire right up, reconnect injector, go wheeling. Then it got worse, and it wouldn't start unless it was fully warm. That's when I got sick of it. I pulled off the rotor just poking around, put it all back together, then it was even worse; if I got it started it wouldn't rev up under any more than light throttle.

Turned out to be a cracked rotor, leaking voltage, I missed it the first time through.

 

[zukkev]

I had a car with exactly the same scenario as yours (only it was a Honda Civic); had good strong spark w/ the plugs out, compression good, ckp/cmp signals appeared good; good inj pulse; but no start most of the time; turned out to be bad distributor--once the ignition was under psi inside cyl, it'd peder out(no spark); We were pullin our hair out w/ this one, untill another honda came in w/ same part # dist...w/ owner's permission ( we knew him well!) we installed it into problem vehicle---and wallah, it cranked right up!!!
Turns out the CMP signal was JUST out of spec---ecm didn't recognize it with spark under load(inside combustion chamber)..... you try salvage yard for a USED dist? Good luck w/ your nightmare!

 

[84Toyota4x4]

If it were mine I would hit it with some starting fluid and try to start........


I'll give you $500 for it.:awesomework:

Starting fluid has no effect on it through either the intake box, throttle body, or straight into the intake manifold via vacuum port. You can have it for $500. Bring a trailer. I'm just gonna get it running and sell it anyway once I get something to replace it.

I had a car with exactly the same scenario as yours (only it was a Honda Civic); had good strong spark w/ the plugs out, compression good, ckp/cmp signals appeared good; good inj pulse; but no start most of the time; turned out to be bad distributor--once the ignition was under psi inside cyl, it'd peder out(no spark); We were pullin our hair out w/ this one, untill another honda came in w/ same part # dist...w/ owner's permission ( we knew him well!) we installed it into problem vehicle---and wallah, it cranked right up!!!
Turns out the CMP signal was JUST out of spec---ecm didn't recognize it with spark under load(inside combustion chamber)..... you try salvage yard for a USED dist? Good luck w/ your nightmare!

Interesting. I have in fact tried calling the Pull A Parts. They say no Aspires. I dunno if they just cant spell it when they type it in the computer, or they really dont have any.

~T.J.

 

[Binder]

You can have it for $500. Bring a trailer.

Pic?

Details?

 

[84Toyota4x4]

Looks like this (this isnt my car though).

PM Sent. I plan to look around for a used distributor some more tomorrow. We'll see how that pans out. I found a car I might be interested in as a replacement that I think I'll look at tomorrow as well so who knows, maybe I could use the money to go with the down payment.

~T.J.

 

[Binder]

PM returned.