Please help me diagnose my no start issue. 5.2 F355

Mine cranks fine just won't start unless I hit the key fob. Have done that a few times because shut car off to wait for wife.

 

If you got no fuel pressure you gotta start there and then see what is next. You can even have failing fuel pump relays that will intermittently work even after the car has started. Those relays suck! An easy thing to do is squirt some start fluid in and see if the car will run for less than 5 seconds. That adds to the confirmation that fuel is an issue. Then you can hot wire the fuel pump and should be able to start the car.

On everything else with a motronic 5.2 that I have seen including the 550 Maranello if you unlock the car wait 120 sec+ the immobilizer resets and the car will not crank. That is your brain tickle to press your FOB to unlock the immoblizer to get the car to crank and then start. If the 355 does not work that way (I can't remember) then that is another stupid thing on the 355 that makes it wonderful. That wonderful trait if DaveRocks is right just clouds the diagnosis on why you have zero fuel pressure. It is possible therefore that Plugzit is right and the immobilizer it AFU and one of it's actions is to kill the fuel circuit. If the immobilizer has done that then there is the way to excorcizing the immobilizer from the 355 going after that fuel kill circuit.

If on the other hand you can rule out bad immobilizer function like you can on any other 5.2 motronic car then you have to start looking at things like wiring, connections, fuel pump, fuel filter fouling, pressure regulators, relays, fusebox. You can eliminate fuel filter, regulators, pumps if you can hot wire the pump and start the car. Then you are down to a wiring issue. The Bosch ECU is very robust. It is extremely unlikely that the problem is there but it certainly can be. You want the problem to be somewhere else cheaper.

 

FBB, as I said above, I'm 100% positive of the following:

1) if the car is locked and you press the FOB, the alarm and immobilizer are both disarmed. If the car is not started within 120 seconds, the immobilizer (not alarm) rearms. To start the car after the 120 seconds requires another press of the FOB

2) the car will crank with the immobilizer armed but it will just not start.

 

First three steps in any non-start diagnosis:
1. Got starter?
2. Got spark?
3. Got fuel?
It's very easy to force #1 and #3. #2 is somewhat more difficult. If you check these three and find two and three missing, then you can check function of 3 (follow the wires from the pumps, checking for voltage at every terminal), and then 2 same way and also while cranking. If they both go all the way to the brain with nothing, but you have voltage to the brain, then you're there....if you didn't get stopped along the way by finding what's wrong. If the starter doesn't work when you jump the terminals even tho you have 12v there, then guess what? Regardless of how mysterious the system is, there are only 3 basics. Ya gotta do the work. Dayum the accessories! Full diagnosis ahead!

 

I have to agree with you. I doubt anybody can do further diagnosis by internet or point you to a certain wire in a certain place. Looks like time to start tracing wires and systems. Best of luck to you and let's hope you find it early in the session!
The "Power Probe" is a great tool for diag, as is the contiuity tester.

 

My 99 f1 works the same as long as the red led is working properly it will also tell you by flashing. When it's flashing car will roll over but no fuel.

 

Sounds like you are losing power to the ECU intermittently.

 

Have you been actively working on this issue for the last 3 months since your last post? Sorry for your troubles.

 

No, depends on the year of the car. My '96 will not crank when immobilized.

Rick

 

Rob in the service manual I believe it discusses the fuel circuit.
I have read that the ecu does store errors even after the power is cut off. If I am reading this correctly it might be quicker just to take the car to a dealer and have them read it through the sd computer. It looks like the computer will give you previous errors and maybe worth the few hundred bucks for the time it will take you to diagnose each part of the fuel and injection system and sensors.

 

I read your very first post and your last post, and this is my wild ash guess.

There may have been a wire or two damaged during the engine out service and it caused the ECU - immobilizer communication to go haywire. The damaged wires further destroyed the ECU board which caused it to go from intermittent to permanent no-start. It was a good guess on your part not to try a working ECU with your car.

If it were my car, I would inspect the wiring harness very carefully for messed up wires. It may require another engine out, but ... c'est la vie.

I also would open up the ECU unit and inspect to see if there is an obvious burnt components. You have nothing to lose with the bad ECU.

I would not put a working ECU in that car until I find the cause and fix it. That is bad but this is not an easy problem. Good luck.

 

There is an analog ground pin in the ECU that is actively driven by an amplifier in the ECU board. They do this to cancel out the noise on this pin. If this is the pin, it will not ohm out to GRD, because it is not GRD.

 

Wow! No 355 over 1 year? I feel for you. If not racing a stand alone will drop the value of your 355 and proper tuning and testing is not as easy as you think especially in a streetcar. OEMs take great pains and spend zillions and still get it wrong. Why not buy a new harness and ECU? Why not take the old harness out and verify/trace every wire? It is tedious but not impossible. Or I'm always on the lookout for a racecar project. I can be in Tuscon Saturday and my Friend needs to buy parts too big to ship from GT Car Parts anyway.

 

Pro efi with fuel composition sensor would be pretty neat. (though I'm not sure entirely necessary).

You could then use 2.7 induction system (with no maf's)

 

~If you are keeping the car, PERIOD to get buried in.
~If you dont need to connect to an OBD for inspection (there is a work around for that also not cost effective yet but soon)
~if you want to tune tune tune then tune some more on the dyno.


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By all means go stand alone !!!!!! These Motronics are slow and wonky
Your in AZ, your weather is pretty flat all you would need is a running AFR to adjust for altitude.