SHO motor that sat too long

[rubydist]

outstanding! the fuel pump inlet screen is a fuel repellent!

 

[Off Road SHO]

Yeah, weird huh. Didn't believe it myself at first.

Tom

 

[Aqua Roach]

Separate the fuel pressure problem from everything else. The relay for the fuel pumps should put +12 volts, relative to the negative terminal on your battery, to the fuel pump cut-off switch in the trunk. Make sure you are using your negative battery post for one side of your VOM or test light.

This will verify that all of the ground paths back to the battery are good. Work your way (with the positive lead of your VOM) from + battery post (record your voltage, should be 12.75 or higher) then to the output of the fuel pump relay at the CCRM at the radiator with the ignition switch turned to "ON" the fuel pump should run for about 1 second, record that voltage, will be quite a bit lower lower than the first reading because there is now another path to ground through the fuel pump). Then read it at the fuel pump cut-out switch in the trunk, shouldn't be too much lower than the second reading.

Tom

At the CCRM we're getting 1.5 volts relative to the chassis ground. The chassis is perfectly grounded to the battery though. But here's the catch, we're getting 1.5v constantly, when the key is "On" and at the fuel pump connection we had got the same, but it jumped to about 3v at "Start" for it's few second duty cycle.

You need more than a gallon of gas in the tank.
When you painted the engine, did you remove the paint in the valley of the block where the ground wire attaches?

I've since filled it with 5 gallons, to no avail.

I've also run down all the grounds that I know, and everything including the block, intake, DIS, and every other ground I can think of is grounded correctly.

We just went through this with 4DR4SHO's new fuel pump and strainer screen. Even with 15 gallons of gas, the new pump would not pump gas, just run. Turns out that the new screen was not allowing gas to get to the pump. So we pressurized the gas tank with an air hose to maybe 3-5 psi. This forced the fuel through the screen to the pump's rotor. The tone of the pump immediately changed and she fired right up.

Tom

This is quite interesting. When I jump the fuel pump, it makes a completely different sound compared to what it's doing now. Since I do have gas at the rails, just not enough pressure, I really don't think this is the problem either.

Though I am interested in how you actually pressurized the tank, did you just go through the gas cap?



I was debating starting the car with a jumper to the fuel pump at a full 12v to see if she'd fire. I read someone else did this but fried their CCRM [because they didn't unhook it, sending current the other way] but if I open the circuit at the fuel pump and connect it to the battery there I'm thinking it would work. The two things I don't want to do is over-pressurize, but there is a return line, or burn up the pump.

Let me know if that's even a good idea. At the same time, even if it does fire up, I would doubt it would again without the jumper.

 

[SHOVNST]

Though I am interested in how you actually pressurized the tank, did you just go through the gas cap?

Yes. He twisted an inflated plastic grocery bag around a long blow gun and sealed that against the filler neck.

 

[Off Road SHO]

I don't think you can burn up the relay by putting 12 volts on the output, but if your worried, temporarily pull the fuel pump fuse until it runs on your 12 volts.

Tom

 

[Shovert]

while it is important to have the ground path to the DIS and to have the DIS heat sink paste applied to keep it from being fried, you already have spark if you can make it run with starting fluid

Got a question. I have read die electric recommended by some. I always correct them and say heat conducting paste. Usually I have get it at a electronic shop like " Radio Shack". That is what I use on TFI on the Mustang and the Dis on SHO motor. Now am I correct? Maurice

 

[Off Road SHO]

Maurice,

They both will conduct heat away from the back plane of the DIS, the heat sink paste will just do it a little better. What is more important is that there be no air space that will trap water. Water will corrode the aluminum surfaces where they touch and corrosion acts like a heat insulator.

Tom

 

[gmail]

The fuel pump has a high and a low side with 2 different relays in the ccrm.. when you jumper the fuel pump you are activating the high side or high pump relay.. this high side only runs at a certain psi of fuel pressure or x amount of load or rpm whatever its set to im not 100% sure on what triggers it but I know it runs the fuel pump harder for more fuel..

Jumpering the relay would do nothing more then running high pump and would not hurt your ccrm. Only thing it could hurt would be fuel pump if ran long term with little fuel as it would get too hot..
Ford had problems with burning up fuel pumps around v6 SHO time and if you noticed on a SHO the fuel light comes on with 5 gals on fuel left in the tank in all SHOs I delt with.. the fuel around the pump keeps it cool and my guess is this is why ford put a high and low fuel pump relay in so the pump can run slower at idle and cruising etc..
I am not sure what the differences in voltage there is so im unsure if your 3 volts is correct or not..

The DIS does need grounded or you have major problems but the thermal paste should be used as well.. the transistors inside the module produce a lot of heat and require the aluminum intake to cool them.

My COP setup is using the crazy expensive bosch bip373 chips which are awesome and have a lot in place to protect them.. they put off enough heat to burn your skin if not heat sinked.


Id suggest checking all connections and grounds as this is where id guess your problem is..

Ill go threw my ford service book tonight to see if I can find certain places to check for you. .

 

[rubydist]

Got a question. I have read die electric recommended by some. I always correct them and say heat conducting paste. Usually I have get it at a electronic shop like " Radio Shack". That is what I use on TFI on the Mustang and the Dis on SHO motor. Now am I correct? Maurice

I use heat sink paste that I get from MicroCenter, the computer place. its job is to aid thermal transfer from the hot part into the heat sink. In the computer world that is from the processor to the heat sink. In the SHO world that is from the power transistor in the DIS into the crossover tube.

 

[Aqua Roach]

Every ground checked out okay. I really think it's a bad CCRM, so I'm going to go junkyard hopping soon and see if I can find any code J's.

From what I researched, correct me if I'm wrong, the feed for the fuel pump goes to the pump and to the PCM. The PCM uses that voltage to monitor the pump's power and operate "other engine functions". My guess is since I'm only getting 3v at startup [you'd think at this point you need the "high" side] the PCM is reacting by not opening my injectors. It's a hunch, but I'm at my wits end and getting nowhere with this right now.

So I'll let y'all know if a new CCRM fixes it. How one goes dead after just sitting on the shelf is beyond me.

 

[Off Road SHO]

Before you blame it on the relay, disconnect the fuel pump at the cut-off switch in the trunk and read the voltage at "engine on". The fuel pump can drag down the voltage. With the fuel pump disconnected you should get full voltage at the disconnect plug.

Tom

 

[Aqua Roach]

Updates:

I've gotten 3 CCRM's at the JY today and tried them all out. Two are okay but one is bad. [Fan came on with car off]

I checked voltage while cranking to the fuel pump, ~11.5v.

No start.

Before I tear down the intake to clean the injectors, can anyone think of anything I could be overlooking? Everything is grounded, everything is getting power.

I appreciate all the help so far.



Update: I've got power to the fuel pump, and I've got pressure. [30psi-38psi at cranking]

I shorted out my injectors while reading the pressure, and sure as **** the pressure drops fast, injectors are not clogged.

Still spins but does not start. CCRM is fine. I never touched the timing when I tore it down. What I don't get is I have spark, and I have fuel, and I have air, but it won't start? I don't have an airbox on it now, it's just the tube with the MAF and the temperature sensor nearby. I do not think that is the problem.

So is it the PCM? The timing? I'm pulling my hair out over here now. Everything I thought it was, it is not.

Thanks.

 

[Off Road SHO]

Hmmmm, this is a tough one. So you've got fuel pressure and spark. The only things left to verify are compression pressure and listen for the injectors firing.

Compression pressure can be checked by pulling any of the front spark plugs and holding a screw driver's handle over the spark plug hole while someone cranks the engine. If you have good compression, it will blow the handle away from the hole with a strong "****" sound.

The injector can be "listened" to with any long screw driver or even a long skinny wooden stick. While you are pressing the blade of the screw driver or end of the stick against fuel injector body or even its wire clip, have someone crank the engine over. If the inject is firing you will hear a definite tick...tick...tick.

If you don't have compression, it's time to see a mechanic.

If you don't hear the injectors firing, one thing that could be causing that is a Wide Open Throttle, or a throttle position sensor that is falsely reporting a WOT condition to the computer. The computer will not fire the injectors (which it does by sending pulses of "ground" to each injector) if the engine is not running and it sees a WOT report from the Throttle Position Sensor. It does that as a cylinder "airing out" procedure. Maybe your throttle position sensor is stuck on full throttle?

Tom

 

[rubydist]

I thought you said the plugs you pulled out were dry.

Just because you can fire the injector manually does not mean it is firing when you try to start the car. You could have a wiring issue, a pcm issue, etc. that keeps the injectors from actually injecting fuel into the cylinder.

 

[Aqua Roach]

That's what's odd, I checked the plugs time and time and they didn't smell the slightest of gasoline. I listened for the injectors too, and I thought I heard them tick twice right before it stopped turning over. [Couldn't really hear them over the starter with just the tube to my ear] I didn't check the plugs since I manually fired them. Could the fuel injectors be firing out of sync with the rest of the engine?

Never thought of the TPS being bad, I'm going to check compression tomorrow then. Everything should be wired up correctly though. For an engine that just sat that worked like a champ before this is just confusing.

Compression is good, timing is good.

Update: Injectors do not fire when engine is turned over. I checked it with a low voltage LED light, they blink when I short them, but not at cranking. Tested TPS, checked out fine.

Camshaft sensor perhaps? What causes the injectors not to fire besides that?

 

[Aqua Roach]

I am going insane over this. I've checked everything with a low voltage LED test light.

I checked the Crankshaft sensor, turning over, see a pulse.
Camshaft sensor, turn it over, see a pulse.
Camshaft at the PCM harness, see a pulse.
PIP Signal at the PCM harness, turn it over, see a pulse.
Each injector wire ohms out, no breaks.
Have spark.
Have fuel pressure.
Everything is grounded properly.
Can turn the engine manually with a test hose attached to a cylinder and feel air puff up.


Okay, sounds like a bad PCM. Bought a new one from SHO Source.
Installed it, still, won't crank. Installed it wearing a static strap and not once touching any pins.

Fuel is still not injecting.

With starting fluid, it just pops.

Checked timing per the timing marks. TDC on cylinder 1 is correct according to the marks. I just stuck a copper wire in the sparkplug well with the plug removed and waited for it to come up all the way and stop. May not be accurate completely but it was in the ballpark.

So, what the **** can it be? This is driving me insane. Any help is greatly appreciated.

 

[kevinspann]

Injectors are stuck closed.

 

[Aqua Roach]

Firing order.

Chilton's manual, should not have followed that.

She started! Did not stop though, I think my ignition wiring needs some help...

Other than that, thanks for all the help! I can't beleive it was as simple as swapping wires.

 

[Mik]

Firing order.

Chilton's manual, should not have followed that.

She started! Did not stop though, I think my ignition wiring needs some help...

Other than that, thanks for all the help! I can't beleive it was as simple as swapping wires.

I'm having the same problem, so you changed the spark plug wires?

 

[Devin]

Which problem? If you need the plug wireless routing diagram, go here
http://www.shopowered.com/diagrams/