Help needed Truck wont start

[Muddy94]

Ok so here is my issue I have a 94 with a 4.0L in it and I can’t seem to get it to start. I have tried everything I can think of. It has good fuel pressure and spark. I replaced my CKS and my ICM. I checked all my fuses and they are all good checked all the relays they are also all good. It turns over very strongly but it just won’t start. I believe my PCM is good because I am still getting my CEL.

Any suggestions would be appreciated.

 

[RonD]

Easiest thing to do first is to spray some starting fluid into the intake and then turn over the engine.
If it fires and dies then Fuel injectors are not providing fuel.

If it doesn't fire using the starting fluid then there is no or not enough spark.

If it fires but sounds like a back fire then cam timing could be off, timing chain issue, so not enough compression to ignite gasoline.

Do you hear fuel pump priming system when key is turned on?
Fuel injectors should always have 12vDC when key is on, the PCM Grounds the injector to "fire" it, so a bad/loose ground at the PCM can prevent injectors from working.
Remove a spark plug and see if it is "wet"

The coil is actually 3 coils, each runs 2 spark plugs, so two spark plugs fire at the same time, one is a "waste spark" , this is another Ground operated system.
The "Coil" should have 12vDC when key is on, the PCM then grounds each coil to "fire" it.
So again ground at PCM is important.
Use Motorcraft spark plugs, Fords seem to kill anything else.

Grounds in general are important in automotive systems, more so since sensors have been added, so check ground straps from battery to engine, body and frame, and then ground strap from engine to firewall, backside driver's side head.


If you get the back fire then check compression or remove valve cover for #1 cylinder and check valves are in the correct position for #1 when it is at TDC.

 

[adsm08]

Have you checked the injector pulse?

 

[Muddy94]

I have sprayed starting fluid into the intake and turned it over.
The Truck turns over and when I let off it will backfire sometimes.
Yes I hear the Fuel pump priming.
Yes the spark plug is wet when removed.
I checked all of my grounds and believe they all have good contact.
I will need to check the compression.



How do you check a injectors pulse?

 

[adsm08]

If the plugs are wet then your injectors are working.


When you say it "turned over" on starting fluid, does that mean it actually caught, or that it just kept cranking?

Have you tried giving it just a hair of gas pedal when you are cranking?

 

[Muddy94]

It means its just cranking.

 

[adsm08]

It means its just cranking.

Try sticking a nickle between the hardstop screw and the throttle lever and then try to start it. If it fires up you probably have a bad IAC.

 

[Muddy94]

Ok I will try that I will have to get back to ya.

 

[Muddy94]

Try sticking a nickle between the hardstop screw and the throttle lever and then try to start it. If it fires up you probably have a bad IAC.

Wouldnt that be the same as hitting the fuel pedal when trying to start it?

 

[RonD]

Try a timing light on #1 plug wire and see if it is firing close to TDC

Have you checked the OBD for codes.
Some '94 4.0l have a cam synchronizer located in the old distributor hole at the back top of the engine, these are a known failure point.

Code 214
Diagnosed Circuit: Camshaft position sensor
Condition: Open or short

The Camshaft Synchronizer tells the PCM when to fire injectors and coils.
The failure of these is usually, but not always, preceded by a squealing/rubbing noise

These were the DIS ignition systems
EDIS just used a the Crank shaft sensor(CKP) and had no Camshaft Synchronizer, my '94 4.0l has the EDIS


How did the engine quit?
Driving and it stalled out or just one morning it wouldn't start

 

[adsm08]

Wouldnt that be the same as hitting the fuel pedal when trying to start it?

Yes, but it's just a hair more precise. Too much pedal while cranking and you put it in a clear flood mode and it gets no fuel.

 

[CKRobin]

What did you do to the truck before you started having the problem? Any chance you got the firing order messed up? That said with the backfire when you let off of it sounds like what my old blazer did when the cam timing was off.

 

[Muddy94]

This is a long story
What happen was I was driving down the road and started to smell antifreez so I pulled off to check out what was happening
I had a pin hole in my lower radiator hose.
I was about 40 minutes from my house and had nothing around to fix it then so I drove home I made it 10 minutes from my house and it started to get hot so I shut it down and got a pull home
I replaced the hose and it took a little bit but I got it started. It smoked for about a minute or to then cleared up. I took it down the road had plenty of power and seemed to be running fine.
I let it run for about 30 minutes and noticed my hose was leeking a little bit so I shut it off and tighting it up and from that point on it will not start back up just turns over.
I don't know if I soaked something with antifreez or what.


I don't know if or what codes I am throwing I need to go get a tester.

I tried the nickle thing didn't help.

Thanks for all the help in advance I just want to drive the thing again.

 

[CKRobin]

Do a compresion test and post the results I bet that will find some inconsistancies.

 

[RonD]

Have you looked at the oil on the dipstick?

Overheating a 4.0l can have painful results.
But engine should still start, just run rough, if a head gasket has failed or head has cracked.

The starting fluid should fire that engine up if spark is happening at the correct time, so if you can, I would try a timing light on #1.

Lower rad hose steam could have damaged the CKP(crank position sensor), long shot but it does control the spark.
It can be tested with a meter set to AC Volts, when crank is turning CKP's two wires should show .3-1.2vAC, it generates its own voltage.


You don't need a scan tool for the '94 OBD I, if it has a Check Engine Light then you can use that and count the flashes.
Read here
http://www.therangerstation.com/tech_library/OBD_I.html
Malfunction Indicator Lamp (MIL) Method



Oh, and if you want to see if the head gasket or head was effected by the over heating there is an easy test that can be done without a running engine.
Get a latex glove and rubber band.
Assuming cooling system is sealed now, no leaks.

Remove rad cap and over flow hose
Place glove over rad cap opening and use rubber band to seal it tight.
I pull a vacuum cap from the intake to seal the over flow opening, but you can use your finger if you have someone who can crank the engine, so seal the over flow opening.

Turn over engine, if glove starts to dance, inflate a bit, then you have a head gasket leak or a cracked head.
If glove doesn't move then you are good.