M7 is dead

89sandman · Jan 12, 2017

Should vary a lot more than that, if it was pulsing the injectors it should show like 15 volts then 5 then 14 then 7 or somewhere closer to 0. So looks like your problem is the computer is not telling the injectors to squirt. I'm not that familiar with the M7 system so need to look up a wiring diagram to make sure where the computer gets its signal from to pulse the injectors. This will be the next place to test.

fordpickupman · Jan 12, 2017

Crank position sensor

Wouldn't the crank position sensor do that?

KMMAC · Jan 12, 2017

check

Check ALL of the electrical connections for moisture,, all it takes is one drop to cause a ground. If you use air to blow out the water, under the hood, I hope the air is dry.
Saw a wiring harness on an efi that had grounded pins inside of the connector and the
evidence of burnt wiring was so little that you could not tell whether it was grime or singed wire. On further inspection, the slots that separated the wires had melted because of grounding from moisture.

fordpickupman · Jan 12, 2017

Wet connections

I've been through all of the connections cleaned them with electrical connections cleaner and put the dielectric grease in them.

Oh yeah, and I swapped out the harness, ecu, injectors, voltage regulator, and tps. The only things that haven't changed are the stator, gauge package & its harness.

The engineer that stuck the plug for the speedo sensor behind that triangular brace, his ears have burned several times I'm sure.

jethrobodean · Jan 12, 2017

Unplug the TSS

TSS, Re adjust the throttle cable slack Dump some gas in them holes and pull.

fordpickupman · Jan 12, 2017

TSS

The TSS was removed a few years ago.

Sledbrain2 · Jan 13, 2017

fordpickupman said:
Wouldn't the crank position sensor do that?

I replaced a crank sensor on my 06 m7. Running issue was it would not accelerate, would start fine. A bad TPS (throttle position sensor) is erratic rpm, hard to start but once running will never settle on rpm. Also I believe all tps from year to year are the same you just need to get the minimum and maximum voltage set right using 5 volts source to set. Does not sound like this is your issue. It sounds to me that the only left to replace is the stator. If your sled has original and is above 1500 miles not a bad idea to change it out as a preventative measure.

Arcticatdan · Jan 13, 2017

Another way to test injectors is put fuel in spark plug hole and get it ready to start. Remove the injectors and put a piece of cardboard in front of the injector nozzle and start. The injector should shoot gas on the cardboard if they are working. Also bond all the grounds together and bond to the voltage regulator and clean all chassis grounds.

jethrobodean · Jan 13, 2017

I have a CF1000 that would start irregular. you could pull for an hr if you had the strength. run great and then die at different times. I changed everthing in that sled. I bought a new throttle cable because the old one was chaffed, cured my problem. And I unplugged the TSS and it still wouldn't start before I replaced the cable.

Rixster · Jan 14, 2017

sounds like a bad lighting coil portion of your stator. I have had 1 from a 900 done with rmstator. https://www.rmstator.com/
Great work and a 1 year warranty. Now you need to figure out why your lighting coil got cooked. Most likely because the tail light was removed without a resistor put in line to replace it.

Mine that went bad on the lighting circuit would ohm test within spec but would not produce any voltage. So just because it tests ok on the ohm test doesnt mean that it isnt bad.
The stator on a efi sled has 3-5 different circuits on it. lighting circuit, injector circuit, fuel pump circuit, and sometimes a circuit for the ecu.

Cedarberry · Jan 14, 2017

fordpickupman said:
The TSS was removed a few years ago.

Any luck yet?

fordpickupman · Jan 14, 2017

Lighting coil

The lighting coil is dead.
I didn't realize it needed power from that circuit to run.
The voltage regulator was bad, I'm sure that is what killed it.
I'm adding an orange "mood" light under the hood to use up the voltage.

I found a used on CL off a running sled. It should be here this next week.
I will probably have Blaine Pertler rewind this dead one. I've had him do one for me before. His service is top quality.

I've read quite a few negatives experiences with RMstator.

Thank you all for you assistance. I was pretty frustrated.

I'll let you all know if this fixes it.

Rixster · Jan 15, 2017

cool, make sure to tie that light into your tail light circuit. you can grab the wires under the coolant bottle. they dive into the tunnel right there along with the coolant line going to the rear cooler.

fordpickupman · Jan 16, 2017

I cut the plug off the tail light harness and soldered the light assembly onto it so that it is a plug in type accessory.
I guess my only question now is if one light bulb is enough to eat up that voltage. I need to dig out the tail light and see how many bulbs it has in it.

fordpickupman · Jan 18, 2017

Update

So it has lights now, but........

It wouldn't fire up. So I dumped some gas down the Y-pipe and it fired up and runs until I shut it off.

What does this mean?
I'm going to read back through this thread and see if I missed anything.

fordpickupman · Jan 18, 2017

Low coolant

When I changed out the throttle body to switch the injectors and tps I lost a bunch of coolant.
I topped it off and out of curiosity it fired up.

It must be part of the failsafe system

fordpickupman · Jan 18, 2017

Never mind

Well, it won't start again.
I pumped 5 gallons out of the tank with its own pump. It was a decent stream. I wanted to look at the pickups. I squeezed the center with my thumb and they would let the fuel flow and take on air. I know they took on air because they floated.

I ran the pump backwards again.
No start.
I pulled the injectors and left them in the rail. They spit fuel like they were cycling. I put them back in and it still won't start.
I don't get it.
I've made run with both ecu's by pouring gas in the ypipe. It will run until I push the kill switch.

jethrobodean · Jan 18, 2017

Low compression....

fordpickupman · Jan 18, 2017

Low Compression?

I don't understand why you keep bringing up compression.
It is an EFI sled and has an electric fuel pump not a vacuum fuel pump. Am I missing something?
As far as compresssion it's plenty hard to pull over and I can feel the compression strokes. I have not checked it for this reason.
Besides, I would have to borrow a tester.

I'm tired of working on it.
No I have a spare ECU, harness, cps, shortblock, and BDX intake.
I loved riding the sled.
I think I'm ready to sell it.

bigjb · Jan 18, 2017

You need to check compression with a gauge not just how it feels. It sounds like you have fuel and spark but if it doesn't have enough compression to move the pistons when it fires you're out of luck.

M7 is dead

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