99 SN GT40 Fuel Supply

Replaced the hi pressure pump,   no wonderful little hum of the hi pressure pump.   Read some more around here and thought what the hell let's play with the man overboard kill switch.   Bingo

All is good with the kill switch bypassed.   


Sidenote - threw away volt meter that showed power to hi pressure pump, when it obviously was not getting power due to the kill switch.

OK all, this has been very informative and helpful but I've got a variance of the problem going on right now.   

I do not get the hi pressure pump buzz, to make it even more interesting after working on it last week I got back to it today. Did nothing but said to myself "let's give this a try" , there it was the hi pressure pump buzz we all know and love, did it 3 times and all is good, put the water on the engine and started the engine right up.   Then about 4 minutes later motor dies and I can not get the high pressure pump to go any more.   

I have tried putting new relays, I tried the jumper suggested above, no go.   Circuit breakers look good, kill switch is in place.   I'm positive this is something easy if I can just find it.

Look forward to hearing your ideas.

Al was hoping all the way along it was not the ECM. You basically have to prove everything else is OK before replacing. I doubt your dealer would have been as logical in fault finding before deciding to just swap out ECM.

Just think what the dealer would have charged you to fix the problem.

There must be a business in the US that repairs auto ECMs. As the GT40 is a Ford auto based solution they use the same ECM (EEC1V) but with a slightly different "program" stored in the PROM (Programable Read Only Memory). If you can find this company send your old computer there for repair. Make sure that they send your original one back.

Well, the ECM came in direct from PCM. It was a freaking old ECM off of some other engine, not even the 300 model that I ordered from a dealer. They sent me a 290. The case on it looked like it was dragged around on the floor vs. mine that looks basically new, so no telling how many hours were on it.

A call to the dealer and he straightened it out with PCM and I am getting a new 300 sent my way.

PCM says that Ford stopped making them so they are getting very hard to get.

My question is: Is there a repair shop that could go through all the resistors etc., on the board and determine what is wrong with it, and repair it? This thing might be worth its weight in gold some day!!

I am going to pop the new "old" ECM on tomorrow hopefully, and see if it at least runs well in the driveway.

Well, the PCM Tech said that there was no test for the ECM, and you can only rule out everything else. I believe we have pretty much accomplished that.

I will order an ECM tomorrow and post results after it is installed.

I appreciate everyone's help out here. I have learned a lot more about the GT40. It has been a great running engine for 12 years, aside from a pump relay issue a couple seasons ago, I have put oil in it, new plugs, and the occasional impellor. So if I need to drop some bucks this year, I guess it will average out to be a pretty low cost over the long haul..

Weather is starting to warm up, so hope this is the fix!!

AB

Ok, pulled out in the driveway and started it up. Ran freaking like new. No hissing, pumps primed, etc., let it warm up and then took it up to 1500rpm and then razzed it and not a missed beat.   

Tried to hookup the code reader to get some KOER readings and although little tringle showed, it wasn't reading, so while engine was running at idle, I disconnected the single grey test lead and grounded it (BECAUSE IT WASN'T READING WITH IT CONNECTED TO READER). Oh boy, the engine jumped up several hundred rpms, started hissing immediately, and died... Looked like code 08 was being displayed, so it was reading a V8. I tried to recall from memory and nothing came back..

I tried to get some KOEO readings, and again, no readings with the single wire plugged into the reader, so I grounded it, and when I did, the pumps primed. Read 11 and 10, so zip and zip. When I unplugged the ground, the pumps primed again.

What the heck? Can the single test lead be tied into shutting the pumps and other stuff off? Or is this all another coincidence to throw me off track for the 20th time??? I THINK THE CODE READER TRIGGERS THE PUMPS WHEN ENGAGED, CORRECT?

Going off to study diagrams...

Went back out to see how it would run again. Started up ok, pumps primed, and idled for a while, took it up to 1500 and then hissing started, then shortly thereafter, missing, loping, and stalled. I could not make it run long enough to get any codes while running. I hooked up KOEO, and again, 11, 10, 11. All clear..   

I tapped on the back of the ECM with key on, and PUMPS PRIME everytime, it is comical..

I am betting the house on a bad ECM and will order one on Monday from the lowest bidder!

I don't know if heat plays a role, as it runs ok for a little when it is cold, then then crappy. I can't explain why it ran well in one of the videos I posted a while back, or why it REALLY ran well today when I started it up. Took rpms great, took throttle bursts without any skipping, like were present in the video, and then just crapped out and ran bad the rest of the time. Could not get it to run like the initial 5 minutes.. The last time I had run it a few days ago before I took the ECM off, it ran like crud, so why it started up like a beast today??

Any last minute thoughts??

Oh, the code reader doesn't really work unless I have it grounded on the battery. For whatever reason, the single wire has to be off and grounding to the block or motor frame doesn't cause the square box to pop up, only ground direct to battery. I am not sure this is significant or not, but would throw it out there..

The larger triangular connector is the STO connect it to Code reader. If the code reader will not communicate with ECM with single STI wire connected to code reader(no link indicator on code reader) disconnect that single STI connector and ground with jumper as the code reader manual indicates. (Page 75)

They are flat.

Bri892001 wrote: Are we absolutely sure the pumps are supposed to prime every time? You definitely checked all the cheap stuff? Tank screen? Antisiphon valve? You know you're getting consistent flow from the low pressure pump out of the tank when you're jumping it? I know the distributor has come up before. Not totally sure how you'd test that. I know sometimes I distributor equipped car that won't take revs can have a bad distributor.

Drained and blew out the tank, changed anti siphon valve, pumps run fine jumpered, but engine still stalls and acts like ignition problem, see pressure on rail and no fire at all. Changed cap and rotor and plugs this spring.

Pumps should prime every time, full pressure or not for 2-3 seconds. Mine are sporadic. They run when STO is jumpered, and with key on engine off with no prime, I tapped on ECM cover and they primed. Several times. Shaking wire harness etc., had no effect.

Are we absolutely sure the pumps are supposed to prime every time?

You definitely checked all the cheap stuff? Tank screen? Antisiphon valve?

You know you're getting consistent flow from the low pressure pump out of the tank when you're jumping it?

I know the distributor has come up before. Not totally sure how you'd test that. I know sometimes I distributor equipped car that won't take revs can have a bad distributor.

i see there are 2 capicators. the tops should be flat. if they are bulged, thet need replaced. its an easy inspection nad easy fix

You just did if you have power at those pins 37,57 and ground on 40,60 then the ECM is getting its power and earth. Take ECM out of housing and inspect as I mentioned previously.

Al,

Yes according to the diagrams pin 57 should have power just like pin 37 and also have continuity back to "87" on EEC relay. It does show a join in the wiring diagram. The join could be anywhere in wiring loom though. Chase the wire back from the pin on connector and see if there is a join before it goes back into the main loom.

***Note*** always remove power when testing continuity.

And you are right earth is earth because the the main heavy earth wire runs from battery -ve terminal right to the cast iron block of engine.

Trying to get codes from the computer will not be possible if the computer has not got power and earth. You may need to catch it when the pumps are priming. You are very close I hope it turns out not to be the ECM.

Lewy, I didn't communicate properly. When I turned the key on to get codes, the pumps didn't prime. So, that was telling me that my system was in trouble mode, so I thought that I would NOT get any codes if power wasn't flowing through the system.

I jumpered the single wire with the STO jumper wire I had rigged up. I grounded it on the block like the STO, not to the negative terminal on the battery like the manual shows. I figured earth is earth.

I will pull apart the 60 Pin and test tonight, then take the ECM apart and see what is in there...

Thanks for all the help.. I have learned a lot, even at times if I have frustrated you and the other guys out here trying to help, I appreciate it!

Well, I took a break tonight and went skiing, behind another SN.

Came home and unboxed the code reader, put the batteris in, and hooked it up to the STO. Turned the ignition on, then turned the code reader on, then hit the test/hold button, as per directions, and zippo. Meter did not show the little triangle in right corner which means that it is accessing the computer codes. Tried this several times, and re-read directions.

Should the engine have some stored codes at least, even if I hadn't run it in a day or two?

Maybe I am just jinxed with electrical stuff!

ps. reading some of the trouble shooting info on the code reader, it indicates that if there is a bad ground, you may have to ground the single plug that is back there with the STO. Hmm, could I have a bad ground and therefore no readings from the ECM?

Ok, this is starting to get me pissed off. I went back out to the boat and when I turned the key on, the pumps didn't prime, I don't know why I wasn't listening for this before. I jumped the single switch direct to a ground like the code reader guide says, and still nothing.

I jiggled all the wires to see if the pumps would prime, and then tapped on the back of the ECM. Bingo! Pumps primed. Tapped again, pumps primed. Did this a few more times.. pumps primed.

No code readings, just stuck on 000. So, my conclusion is that the ECM is not making a good ground, or has some faulty connections internally, and I am not going to get code readings from it, just as my engine is not getting proper signals.. Thoughts?

I don't think I will be buying a $1000 fuse block for more testing, but that might be the only way to get to the true answer, as that is how you test the ECM, right?

Still going through hell, but seeing some light..