94Mazda b3000 crank but no start

[sumnerwayne@ymail.com]

Did the head gaskets on my 94 b3000. The engine cranks gets fuel gets spark. Set timing up right but just will not pop. Any thing im missing? I have one stray plug with a purple and yellow and orange and yellow wire in The back of upper intake manifold. Need help asap

 

[RonD]

gets fuel?
Have you manually added fuel to the intake?
Spray Quick Start(ether) or Carb Cleaning into intake

I would do that first, if it starts and dies then fuel is the issue, it is doesn't start then spark is the issue.

Did you remove the distributor?
If so you could have it 180deg out, there are TWO #1 Top dead centers(TDC) in a distributors rotation, #1 TDC and #5 TDC, are the same mark on the crank, so distributor rotor could be pointed at #1 but should be pointed at #5, 180deg out.

If you have a manual trans then there will be a connector with a Purple wire, and a few more, that would have gone to automatic's neutral Safety switch(NSS), so this would just be left hanging on a vehicle with manual trans.
It should have a cap on it, but it often falls off

 

[sumnerwayne@ymail.com]

gets fuel?
Have you manually added fuel to the intake?
Spray Quick Start(ether) or Carb Cleaning into intake

I would do that first, if it starts and dies then fuel is the issue, it is doesn't start then spark is the issue.

Did you remove the distributor?
If so you could have it 180deg out, there are TWO #1 Top dead centers(TDC) in a distributors rotation, #1 TDC and #5 TDC, are the same mark on the crank, so distributor rotor could be pointed at #1 but should be pointed at #5, 180deg out.

If you have a manual trans then there will be a connector with a Purple wire, and a few more, that would have gone to automatic's neutral Safety switch(NSS), so this would just be left hanging on a vehicle with manual trans.
It should have a cap on it, but it often falls off

I have not added fuel manually but I have pulled the plugs and they are wet.

I have tdc correct its on the number 1 plug in the compression stroke (felt the pressure build with number 1 plug out) checked spark by grounding plug to block

.it is a manual trans as well so glad that rules out an issue.

Also replaced dist cap and rotor.

So disappointed reading about bad cam sensors or broken dist gears but my dist is creating spark and rotor is changing positions. I have literally removed dist cap 10-15 Times today as well as plugs double checking timing

 

[RonD]

Wet spark plug tips would tend to confirm fuel injection is working.

1994 3.0l uses distributor and TFI module as the Crank and Cam sensors, these sensors were not added, or needed, until distributors were removed.
So spark system provides RPM data and Fuel injector timing, along with spark timing of course.

The Big 3 for gas engines:
Spark
Fuel
Compression

I would still try to add fuel manually, and see if it fires, if not then you confirm spark or compression is the problem.

If you have a compression gauge then test a cylinder, over 110psi will usually allow spark plug to ignite air/fuel mix in a cold engine, 3.0l should be above 150psi.
If low, did you get the valve train back on correctly and tight, no loose push rods.

If compression is OK then spark is all that is left.
Confirm #1 TDC compression stroke again, make sure you are rotating the crank in the right direction, if you rotate it backwards you could be on #5 compression stroke.

You can also put a jumper wire from Battery + to the Coil's +, "hot wiring 101", this will provide 12volts to coil to take ignition(key) system off the table as a problem.

 

[sumnerwayne@ymail.com]

Wet spark plug tips would tend to confirm fuel injection is working.

1994 3.0l uses distributor and TFI module as the Crank and Cam sensors, these sensors were not added, or needed, until distributors were removed.
So spark system provides RPM data and Fuel injector timing, along with spark timing of course.

The Big 3 for gas engines:
Spark
Fuel
Compression

I would still try to add fuel manually, and see if it fires, if not then you confirm spark or compression is the problem.

If you have a compression gauge then test a cylinder, over 110psi will usually allow spark plug to ignite air/fuel mix in a cold engine, 3.0l should be above 150psi.
If low, did you get the valve train back on correctly and tight, no loose push rods.

If compression is OK then spark is all that is left.
Confirm #1 TDC compression stroke again, make sure you are rotating the crank in the right direction, if you rotate it backwards you could be on #5 compression stroke.

You can also put a jumper wire from Battery + to the Coil's +, "hot wiring 101", this will provide 12volts to coil to take ignition(key) system off the table as a problem.

Went and got new plugs. Had ignition coil tested came out good.

Tried administering fuel manually. No fire. Though after cranking the engine it seems to want to keep turning over but stops short.

Push rods were all snugged down tight no up and down movement but i read that you should be able to rotate rods when snugged down. I didnt read that untill after everything was back on.

Suppose i should try a leak down maybe these heads were shot from the get go

 

[RonD]

I would confirm #1 compression stroke and rotor position.

Firing Order 1-4-2-5-3-6 Clockwise rotation

To have ALL cylinders not firing wouldn't be a head issue, compression is also a long shot since it would have to effect ALL cylinders to prevent any firing.

Usually it comes down to spark or fuel with a no start on an engine with a timing chain, timing belts can break, so no start, timing chains can skip so less power but rarely a no start.

If you added fuel manually and still no firing then it is down to spark, that is where I would focus the time.

TFI testing is outlined here: http://www.therangerstation.com/tech_library/TFI_Diagnostic.shtml

There is a separate START and RUN power path for TFI, that is why I mentioned using the jumper wire from the battery to the coil.
When you turn the key to START the power for TFI and coil go thru a Safety switch, Clutch switch or Park/Neutral switch, and RUN power is cut off, if the safety switch is not passing the START power then spark won't work while cranking engine, but you will have power at TFI and coil with key on(RUN), so it can be perplexing, you have power but no start.

 

[sumnerwayne@ymail.com]

I would confirm #1 compression stroke and rotor position.

Firing Order 1-4-2-5-3-6 Clockwise rotation

To have ALL cylinders not firing wouldn't be a head issue, compression is also a long shot since it would have to effect ALL cylinders to prevent any firing.

Usually it comes down to spark or fuel with a no start on an engine with a timing chain, timing belts can break, so no start, timing chains can skip so less power but rarely a no start.

If you added fuel manually and still no firing then it is down to spark, that is where I would focus the time.

TFI testing is outlined here: http://www.therangerstation.com/tech_library/TFI_Diagnostic.shtml

There is a separate START and RUN power path for TFI, that is why I mentioned using the jumper wire from the battery to the coil.
When you turn the key to START the power for TFI and coil go thru a Safety switch, Clutch switch or Park/Neutral switch, and RUN power is cut off, if the safety switch is not passing the START power then spark won't work while cranking engine, but you will have power at TFI and coil with key on(RUN), so it can be perplexing, you have power but no start.

It starts now! But no throttle response.

Stays at a steady idle when given gas, egr tube near exaust has bad crack in it.

What would cause no throttle response?

 

[RonD]

TPS(throttle position sensor) is not plugged in
MAF(mass air flow) sensor is not plugged in
SPOUT jumper is out, so no spark advance

EGR tube crack wouldn't effect throttle response.

What was wrong before?
The no start

 

[sumnerwayne@ymail.com]

TPS(throttle position sensor) is not plugged in
MAF(mass air flow) sensor is not plugged in
SPOUT jumper is out, so no spark advance

EGR tube crack wouldn't effect throttle response.

What was wrong before?
The no start

Pretty sure tps and Maf is plugged in.

Not sure where the spout is but I've heard of needing to be unplugged when adjusting timing but I never disconnected it yet

I honestly don't know what it could have been I cleaned up inside the dist where the contact points are where the rotor sits on with sand paper and a wire brush tried starting and no start still

Went inside and called a buddy he said check comp which I went out and Got the #1 cyl ready went to crank it and it started so I reinstalled the plug and it ran gave it gas and nothing just idled. Maybe a bad dist all together?

Thinking it was flooding out and since I cleaned it up it got better spark but maybe still not enough to put out the power.

 

[RonD]

Distributor would be a long shot, hall effect sensor inside is pretty bullet proof, TFI module is more likely.
And usual distributor issue would be misfiring as RPMs increase, not no increase.

When you open the throttle the RPMs should just go up because you are releasing the vacuum in the intake that holds the RPMs down at idle levels.

Thats what IAC(idle air control) valve does to set the idle, it allows less air in to lower idle and more air in to increase it.
So if you open the throttle plate a running engine will just naturally speed up, may start missing or running rough because there is not enough fuel, but RPMs should still go up.

 

[sumnerwayne@ymail.com]

So i may have the tfi in my dist or theres one mounted on firewall or by rad mount?

Tfi will prevent the engi e from revving? The idle is very low id say 500rpm barely registering