Can't this @#$%er started!

[Recon!]

Haven't been around in a while, been working a lot lately. But I do find a little time for wrenching on the trucks.

Last week I put in a used VDO tach and started it and checked to make sure the tach worked. Everything good.

A few days ago my battery is dead, so I decide to jump it with my F250. It just cranks. It's getting fuel, I can smell it at the TBI. What is really irritating is that it has always started the first crank the 1 1/2 years I have owned it. It's uber hot here, so day wrenching is nearly out of the question.

I think I may need to do my plugs/cap/wires, even though they are only a little over a year old. Today the tach shorted out while I was cranking it, it sparked real good.

I checked all the fuses, all good there.

Any help?

 

[Recon!]

My sig is gone. Hmm. 89 K5 with a 350 TBI, all stock except a msd coil

 

[Recon!]

Just pulled the plugs, they are perfect. I had to come inside for more tools, so now I'm gonna pull the cap from the distributer

 

[EIB8400]

Fuel pump maybe? Not sure on your truck but on newer ones if it doesn't have enough fuel pressure it will not fire.

 

[Recon!]

Yea, I think the pump is out, I can't hear it run before cranking anymore. Damn it.

 

[Fordum]

Go back to the basics. Is the gas old? Normally I would not mention it, but this modern gas can go bad in a month.
If the gas is good, check on the spark.

Since the problems started with the tach, I suspect that is where your problem is.
Most likely it killed your battery. They are prone to do that if they have a problem or are hooked up wrong.
Best guess, is that it damaged your ignition module. Pull a plug wire and see if you have good spark.

If you have good spark, and the gas is spraying good, try cranking it with the pedal held all the way down to put it in flood mode.

 

[Fordum]

Remember, it only runs for about 5 seconds after you turn the key on if the motor does not crank.

 

[Recon!]

Go back to the basics. Is the gas old? Normally I would not mention it, but this modern gas can go bad in a month.
If the gas is good, check on the spark.

Since the problems started with the tach, I suspect that is where your problem is.
Most likely it killed your battery. They are prone to do that if they have a problem or are hooked up wrong.
Best guess, is that it damaged your ignition module. Pull a plug wire and see if you have good spark.

If you have good spark, and the gas is spraying good, try cranking it with the pedal held all the way down to put it in flood mode.

The gas is old, except the 4 gallons I've put in there trying to figure this thing out. It has just over a 1/4 of a tank in it now.

The battery went because I left the door open while putting in my head light relays and then the tach a few days later. Like I said, it started fine with the tach installed but it wouldn't a week later.

I work on this thing alone and all my friends are in Iraq right now, so I have no way to check spark that I know of off hand.

If it is the ignition module, where is that located and how would I check that? Or is it a replace and hope it works type thing? I really don't want to drop the tank.

 

[Fordum]

OK, gotta backup and reload.
I assumed a higher level of knowledge. No problem, I just been hanging around with these guys too long.

If the battery is hot, turn off everything that makes noise. If you have any kind of help, take the gas cap off and put your ear next to the hole and let someone turn the ignition on.
If you have no help, make sure its quiet around you and turn the key on and listen.
You should be able to hear the pump run for a few seconds when you first turn the key on.
If you are not sure, turn the key off and back on. You get about a 5 second shot each time.

If you hear the pump, we will assume its good for now.

To check the spark, you will almost certainly need someone to help. There are several ways.
You can pull a sparkplug wire off a plug, stick a screwdriver inside the boot, and lay it so it almost touches the engine.
You should see a nice fat blue spark when the engine spins over.

You could also pull a plug, and lay it on the engine with the wire hooked up and watch for the spark.
If you have a spare plug, use it. If not, there will be a loud whooshing noise from the open spark plug hole.
Don't worry about it.

I have checked for spark by myself before. Its tricky, but you can usually rig something up that you can see under the edge of the hood while in the driver seat.
Helps if its dark.

The ignition module is on the dist., but I'm embarresed to say I have never changed one.
I do more Fords than Chevys.
Have no fear though, there are lots of folks here who can talk you through it.

Be sure to disconnect all the tach wires before you do any
more cranking. It may not help, but first rule when trying to fix something is to undo whatever you did just before it quit.
Even if it ran once, that was before it sparked......

If you have spark, and you hear the pump, I'm gonna go with bad gas. That fresh you put in might not be enough.

 

[Recon!]

OK, gotta backup and reload.
I assumed a higher level of knowledge. No problem, I just been hanging around with these guys too long.

If the battery is hot, turn off everything that makes noise. If you have any kind of help, take the gas cap off and put your ear next to the hole and let someone turn the ignition on.
If you have no help, make sure its quiet around you and turn the key on and listen.
You should be able to hear the pump run for a few seconds when you first turn the key on.
If you are not sure, turn the key off and back on. You get about a 5 second shot each time.

If you hear the pump, we will assume its good for now.

To check the spark, you will almost certainly need someone to help. There are several ways.
You can pull a sparkplug wire off a plug, stick a screwdriver inside the boot, and lay it so it almost touches the engine.
You should see a nice fat blue spark when the engine spins over.

You could also pull a plug, and lay it on the engine with the wire hooked up and watch for the spark.
If you have a spare plug, use it. If not, there will be a loud whooshing noise from the open spark plug hole.
Don't worry about it.

I have checked for spark by myself before. Its tricky, but you can usually rig something up that you can see under the edge of the hood while in the driver seat.
Helps if its dark.

The ignition module is on the dist., but I'm embarresed to say I have never changed one.
I do more Fords than Chevys.
Have no fear though, there are lots of folks here who can talk you through it.

Be sure to disconnect all the tach wires before you do any
more cranking. It may not help, but first rule when trying to fix something is to undo whatever you did just before it quit.
Even if it ran once, that was before it sparked......

If you have spark, and you hear the pump, I'm gonna go with bad gas. That fresh you put in might not be enough.

I disconnected the tach and still nothing.

I can hear the pump, so I assume it's not that.

When I pulled the plugs, they had fuel on them like it was flooding and not sparking.

I think I will have to try and get a guy from work to come over and help me trouble shoot the spark. Luckily he lives right down the road and I have beer.

I looked around at various websites and a replacement ignition control module isn't that expensive and if it's in the distributer then I can easily do it.

I have the knowledge to figure out how to replace something and do it right the first time. The hard part for me is diagnosing the problem before throwing money at it.

 

[Fordum]

Got a propane torch? If the plugs are wet, then the engine is flooded and the plugs are fuel fouled.
If you can do a quick check for spark go ahead. If you have spark, pull the plugs, making sure of where the wires go, and then hold them with pliers and heat the electrodes (the part that the spark jumps across) until they are faintly red hot.
While you are doing that, hold the accelerator pedal all the way to the floor, and let it spin a few seconds.
This will blow most of the fuel out of the engine through the open plug holes.

Then, after you get the plugs burned off, put them back in and see if it will crank.
You would get the same symptoms if the fuel is bad and can't ignite. But with clean plugs and dry cylinders it ought to at least sputter.

Changing the module is simple and cheap. Most anyone here can talk you through it. Most of them have changed a few, and most carry a spare in the truck.
There should be some heat sink compound or grease on the old one.Be sure to put some between the new one and what it mounts to.

Hang in there. This site can talk you through fixing almost anything. More people will be chiming in soon.

 

[Recon!]

I do have a propane torch. I have never heard of that trick, and I may have to try it out tomorrow before work if I get a chance. I work second shift right now, so my schedules all screwy.

I wish I wasn't such a maniac when it comes to my temper, I had to walk away from it in frustration.

 

[Fordum]

No problem. I had to go eat some supper. Gonna have to go to bed pretty soon, but I wanted to check back in.

The torch trick works real good on a single cylinder lawn mower. In your case, you're cleaning the plugs.
It will burn the carbon and other fouling off. You can see it glowing brighter and flaking off.

With a lawn mower, you can get the plug good and clean and then screw it in hot.
Helps vaporize the gas and makes it crank.
Can't do that with a truck. Too many plugs and too hard to put them back hot.
But it does a good cleaning job.

Just do what you can, hopefully there will be some other ideas tomorrow.

 

[sniperthx1]

Some auto parts stores can test the ignition control module.

All you gotta do to get at it is pull the disributor cap, unhook the three connectors, and unscrew the module. Very simple, four screws total.

 

[Fordum]

Having never had one to worry about, I can only go by what I read here. Out of dozens of threads, it sounds like the reliability of store testing of those is about 50%.
At best.
But that is for trucks that have intermittent problems. If the coil is not firing at all, I would suspect that a bad module would be much easier to detect.

 

[sniperthx1]

That is why I usually have mine tested multiple times.

When I tested it at the auto shop in my backyard, It failed the first test, passed the second, passed the third, and when I shook it, failed the fourth.

A good one should never fail, but a bad one may occasionally pass.

 

[wasted wages]

quick... easy test....

remove the dist cap from the dist....

you will see a few plugs where wires plug into the cap ( not the plug wires the small ones...)

leave the one with the wide plug attached to the cap.... this is the one that leads into the module inside the dist itself..

there are two other plugs.... one is where you should have connected the tach..and the other is 12 volt + when you turn on the key.

unplug both of them...

Take a piece of wire from the 12 volt + terminal on the cap ( crimp a terminal on to fit the wire to the cap) and then put the cap back on the dist.

attach the other end of the wire to the + on the battery.
crank the engine.
it should start or make plenty of spark at the plugs.

basically what you are doing is eliminating ALL of the wiring in the truck and hot wiring the dist. If you don't get any spark still... then it's in the dist itself.... module/coil/bad ground...

HEI's are so easy.... you can hook one to 12 volts and spin the drive gear with your hand and they will throw spark...


Are you sure the rotor is turning ?

long shot but I have seen a broken drive gear pins or a broken timing chain throw a lot of people...
bump the engine with the cap off .... make sure the rotor moves....

 

[Recon!]

quick... easy test....

remove the dist cap from the dist....

you will see a few plugs where wires plug into the cap ( not the plug wires the small ones...)

leave the one with the wide plug attached to the cap.... this is the one that leads into the module inside the dist itself..

there are two other plugs.... one is where you should have connected the tach..and the other is 12 volt + when you turn on the key.

unplug both of them...

Take a piece of wire from the 12 volt + terminal on the cap ( crimp a terminal on to fit the wire to the cap) and then put the cap back on the dist.

attach the other end of the wire to the + on the battery.
crank the engine.
it should start or make plenty of spark at the plugs.

basically what you are doing is eliminating ALL of the wiring in the truck and hot wiring the dist. If you don't get any spark still... then it's in the dist itself.... module/coil/bad ground...

HEI's are so easy.... you can hook one to 12 volts and spin the drive gear with your hand and they will throw spark...


Are you sure the rotor is turning ?

long shot but I have seen a broken drive gear pins or a broken timing chain throw a lot of people...
bump the engine with the cap off .... make sure the rotor moves....

My cap is not the traditional hei cap. The coil is separate and the wires to the icm are not connected to the cap at all. But it sounds like I can still do this trick.

I had the icm tested at two places for a total of six times and it passed every time. I'll report back after some more diagnosing.

 

[4xcrazy]

A couple of quick shots of ether down the throttle bores will let ya know if there is or isn't spark. That stuff will definately ignite if there is.

 

[diesel4me]

Check for a blown ECM fuse???....they sometimes pop for no good reason,especially on a vehicle that sat a long time and then gets rudely awakened with a jump start from a running jump vehicle..modules can pop that way too--I suspect your module may have been fried when the tach malfunctioned--grounding the tach terminal on an HEI is fatal to the module --some TBI modules have two sections,one for fuel to trigger the injectors and another to fire the plugs--one or both can fail,and not always STAY "dead",they might work fine for a minute,hours,or days,then crap out again...and testers dont always simulate real world conditions....if there is no spark I'd try another module,if that fails to help it could be the pick up coil or crank sensor depending on what your truck uses also...

Older HEI's can be quickly tested by putting a 12V test lamp between the tach terminal and ground and cranking it over for a few seconds,--if its getting 12V and the module and pick up are working the light will blink on and off as you crank it over...you can unplug an injector and put a # 194 bulb across the two wires and see if it flashes while cranking to see if the injectors are firing also...

A crude test of the fuel pump can be done by using a tire presure gauge on the test port on the injector rail ,or even by just pressing the little valve pin inwards and see if gas squirts out--watch your eyes and no smoking!!!..a good way to check for spark all alone is to get an old headlamp bulb that burned out and hook the plug wire to one side of the bulb and ground the other lead,and crank the engine--the spark will jump across the burned out filament and its easy to see,even in daylight...