360 CH starts and dies

I am working on a 360 Challenge that was running perfectly until the owner ran it out of gas.
Now it will start and run for about 20 seconds and then dies. It will restart only if the accelerator pedal is pressed completely to floor. The moment you back off the engine dies.
We have a Leonardo and after diagnosing several minor electrical problems and curing them the condition remains.
Fuel pressure is good and there is no dirt or sediment in the fuel system.
Flywheel sensors have been swapped with another car that runs...no change
Electronic throttles and MAFs thoroughly checked
Spark plugs replaced
ECU multi pin connector cleaned along with almost every other connector
O2 sensor disconnected...no difference
Pneumatic throttle valves checked and all vacuum lines
Water temp sensor checked
Several scans for OBD faults...no codes appear.

I am out of ideas?

 

If your fuel pressure is good then from what you described it sounds to me that your injectors may be clogged with dirt and now need an ultrasonic clean. If you have access to another 360 simply swap over the whole fuel injector rails on both sides (very easy to do) and this should help eliminate this or otherwise out of the equation.

 

The injectors had been to RC Injectors and got the full treatment. I did pull both rails, cleaned them inside and out along with injectors...again.
I am now wondering about the device that sits below the intake manifold and activates the butterflies in the manifold itself?
I swapped the two pneumatic solenoid valves from another car and the car now runs much longer and has some throttle response?

 

Several possible issues:

1. Physical contaminants at the bottom of the tank were sent to the injectors as it ran out of gas. This "dirt" could be clogging the injectors. It would have to clog >4 injectors to cause it not to run. This would not explain the 20 sec run time. I have had 6 cyl with 6x clogged injectors. It will just not start at all.
-Likelihood of this being the issue [ 3/10 ]

2. Too much fuel. On a cable driven throttle body vehicle I would point to too much fuel, not enough air. This is because of the observation that at full throttle the vehicle will run. I have had this before on carberated vehicles with cable throttles. You would also smell fuel in the exhaust because the cats wont be hot enough to catalyze the unburnt fuel.
Q1: Do you smell gas?
Q2: Can you observe what the throttle valve position is during a start attempt at full throttle pedal actuation? I dont know how the software will respond to full throttle at starting rpm.

3. Too much or too little fuel pressure.
Q1. Have you checked the fuel pressure?

4. After a failed start are the plugs wet with fuel or dry?

5. Have you verified spark after it dies (not likely the issue)

6. Can you measure the 20 seconds with precision? Do like 5 starts and time them all. If its exactly 20 seconds and a hard stop than its more likely something with a clock, i.e. the ECU, as opposed to analog items like fuel pump, MAF, O2.

7a. After the 20 second run, does it sputter out or die hard? If it sputters out it could be a drop in fuel pressure.

7b. During the 20 seconds are you able to rev it freely? If the revving shortens the 20 sec run then its likely fuel pressure related, maybe after priming the fuel pump does not run at all.

8. Have you verified the fuel pump? Question 3 will make this question moot.

Most of the time in these strange situations you tend to stumble on the actual failure while running through a fairly standard check list like this. Good luck

 

Trent,

Thank you for responding.

1) Both tanks are filled with foam since it is a Challenge car. My first step was to pull Fuel pumps and inspect the foam. It is in good shape and there is no appreciable sediment near the pump pick up area.
2) The engine is running very rich for sure. Even back fires sometimes on start up. I spent considerable time on the throttle/gas pedal system making sure it was opening correctly. All test were verified by the Leonardo.
3) Fuel pressure is perfect and his been checked multiple times. Even drain back is reasonable.
4) Some of the plugs are wet.
5) spark is good
7) car does rev freely while running but only with throttle well open.

I am trying to remove to inspect the big solenoid valve under the intake manifold? See #16
View attachment scan-4.pdf

 

With all your checking and double checking the only thing out of your personal control was the injectors to RC eng. Are you sure they did a good job. I used to use them. They are down the street from me but in the last few years their quality has been lacking or they got so much business they just don't care about me anymore so I use someone else. Did you actually try a fuel rail with injector swap from another car? A neat trick before you swap would be to run some starter fluid in the intake just about a second before the car wants to die. If it runs on the starter fluid you got your answer.

 

I don't think that big valve that activates the inlet cross-over system can be responsible. I know on my car I can manually do the work of that valve and it makes no discernible difference whatsoever (save only the rattle from the worn shaft on which the secondary butterflies sit dies away). All that system does is allow shorter/longer inlet tract length. You can hold it half open, closed or fully open and it makes no difference to tick over on a running engine.

I favour the possibility of clogging injectors (notwithstanding the cleaning that has been done). AS suggested, a swap out of the entire rail x 2 from a known working set-up would be quick and easy. Again, the spray of starter fluid would be interesting.

If this were a carb'd engine I'd say she's running way too rich. Holding the throttle valves fully open allows loads of air in and if that's what's needed to get combustion it's suggesting to me that there's an over-rich situation. Such a condition could perhaps be generated by the needles in the injectors failing to close due to dirt.

Something else to check - the cable loom for bank 1~4 crosses over and connects with the throttle body and MAF on the opposite side (and obviously the opposite applies on the other bank). If the cables were all disconnected it's possible they were re-connected incorrectly.

Another something - is it possible that the plugs for various injectors were reconnected to the wrong cylinder number? I know the spark plug leads are all neatly numbered and next to impossible to mix up but perhaps there's greater room for confusion with the injectors cables and plugs?

You mention .......I swapped the two pneumatic solenoid valves from another car and the car now runs much longer and has some throttle response?" What valves are these?

Question. After it cuts out will it start again straight away or is it flooded and needs time to clear?

Hope my observations and questions are of some assistance. It's likely to be something pretty simple and brainstorming like this is often of assistance.

Best of luck!

 

I think you have narrowed it down to a rich condition; With FI there are only a few options.

R1. Fuel pressure too high. You have already confirmed this is not the case as you have checked the pressure.

R2. Injectors leaking. You can test this by pulling a rail and pressuring the system. Dont try and start the car, would be an awful mess and dangerous with warm engine (as you surely know)

R3. The injector signal wire is shorted somewhere, because you have 8x signal wires and your 4 stroke will run on 4 cylinders, this seems unlikely. But you should check the duty cycle on the injectors. You can do this by putting an oscilloscope on the two injector wires and setting the time sweep to ( 1000rpm = 16.6hz = 60mS ) so maybe 500mS sweep. For cold start you duty should be quite low, well under 10%.

R4. Bad ECU or misprogrammed ECU if you have a "tuned" challenge car. Grab a spare set of ECUs from a regular 360 or working Challenge. i.e. if one accidentally put the low load, low RPM fuel too high, I could see this happening, and would show up on the oscilloscope as a high duty cycle at start.

 

I would say it's not dirty (Clogged) fuel injectors. Fuel pumps either in-tank or inline will always have a pre-filter and in some cases a post filter. In-Tank fuel pumps have a fine (Measured in Microns) filter bladder attached at the pick up, it would have to have a tear in it or have fallen off. If either was the case you would then have this debris sucked into the pump sent down the fuel lines and stuck into the Fuel injector pre-filter, this would have caught any debris and small particles. Now if this did happen then the cleaning and the replacement of the Fuel injector pre-filter would have eliminated the clogged fuel injectors.

I am not a Ferrari Mechanic but I have cleaned many fuel injectors and sold many Fuel pumps of all types. I personally do not believe you have a fuel injector problem.

However a fuel pump problem maybe. If the tanks were ran dry in-tank pumps will burn up very fast. However you say you show soild fuel pressure. On the Challenge car is the fuel pressure measure on individual banks? (Fuel Rails) or is it measured on the scanner?

Also Faulty injectors. I would check the Ohms on all 8 injectors to make sure you are working with all 8 functioning injectors. If they are not pulsing correctly and just spitting fuel out then that is an issue.

If you have wet spark plugs then you may have a leaking injector(s) or no spark in that cylinder(s)

I'd imagine that RC performed a leak test. Did you receive any paper work from them?
You should have a document from them listing Impedance, Spray Pattern rating, CC/min etc. this would help eliminate the fuel injectors.

However I would still check the Ohms on each injector to make sure they are functioning. And check to see that both Fuel pumps are fully functioning.

See pics below, (These are not actual ferrari parts just examples) Pics on the left are fuel injector pre-filters. Pics on the right are a standard in-tank fuel pump pick up pre-filter.

Chris.
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Thanks to all contributors. Yes i did get paperwork from RC and everything is excellent. I have been using them for a very long time and was made aware of them by Porsche Motorsport.

Thanks for the clarification on the big vacuum valve under the manifold. I still feel the engine is starving for air but not sure what is causing it. Please recall my statement that the car ran perfectly and the engine was very strong before he ran out of fuel. Pumps are strong and fuel bleed back is minimal.

I will with injectors rails this morning but am not convinced it will prove anything.

 

Q1: What do you men by "fuel bleed back is minimal."?

Running out of gas can cause a few issues on FI, mostly the old systems though;

1. On systems without return lines; running out of fuel "could" put air in the system. With a return line, like the 360/430 and most modern FI systems use this is no longer an issue to my knowledge.

2. The fuel pumps could overheat and be damaged. This is unlikely for several reasons in this situation.
a. You state there is plenty of fuel pressure.
b. You state the return line is working as expected
c. The odds of both pumps being damaged is low
*Note that fuel is required to COOL the pumps, running the pumps dry for long durations can damage them.

One interesting comment. The 360/430s have two separate systems, one for each bank of 4x cyl. Thus each bank has their own Tank, Fuel Pump, ECU, COPs, ThrottleBody, MAF, O2s, Filters. The car should run rough on 4 cyl, but should still run. So what could cause both systems to fail at the same time.

If anyone reflashed both ECUs, I would reverify with known good units.

To idle the vehicle needs almost no air, so if it wont idle, and its an air/fuel, its usually fuel.

Have you verified the signal from the throttle pedal POT? You can get its value from your SD2/3 or equiv, or from a good OBDII reader with real time stats.

One more random thought. As the car runs out of gas the combustion goes lean which can cause cylinder damage fast, especially under high load (racing), damage the knock sensors cant protect from. This is usually not an issue because at mega lean there is no combustion, thus no really hot burns, and the damage from lean is heat and oil scavenging related usually. Have you verified compression? Leakdown? Gas in Oil? Dont rule out mechanical failure.

 

And you've verified the spray pattern of the injectors?
No residual depressurization of the fuel system I presume..

No changes to ECU programming?
You did the turn off power for 20 min to reset things (I know.. just have to ask)

any possibility could be other cause e.g. F1 cutting out the ignition or fuel?

It's usually something simple...

 

When I say bleed back I am referring to watching an test pressure gauge to see if the test pressure is maintained with pumps off and how long does it take for the pressure readings to come down?

I am trying to contact the previous owner about a reflash.

As far as spray pattern is concerned that is also addressed in RC report. IMHO not an issue.

This morning, after sitting all night it started and ran nicely for about a minute then stalled and would not restart? I have been checking and cleaning all electrical connections in the driver's compartment behind both seats.

This has been a real adventure!

 

Coolant temperture sensor

 

edited already checked, I would watch fuel pressure when its idling and see if it drops before car shuts off.

Could be any number of sensors that are killing fuel, data logging would give you a clue to what is active.

 

Things like this will be interesting to check out. I presume erroneously sending signal to ECU to enrichen? Coincidental to gas loss...?

 

Coolant temperature sensor has been tested. When disconnected the ECU actually reads -46 degrees F. Cold enough to keep any cold start circuit active for longer than 20 seconds.

After cleaning many of the white multi pin connectors I can get the car to run for a minute on its' own and if I am careful with the accelerator pedal longer. After which I am now getting two codes; P1104 Air Flow Meter: Low (2) and P1269 Throttle Safety Function (B2): Range.

I have replaced air flow meter with new unit and even switched side to side. It has to be a wiring issue? Not sure what a throttle safety function is?

 

Inertia switch

 

Wouldn't that shut everything down? I will try swapping one.

 

Are you sure owner "only" ran car out of fuel and nothing else happened? Maybe ask for other clues. I cannot see running out of fuel resulting in this. Like someone else said, since this doesn't make much sense, maybe start with the basics (such as compression, cam timing, ...) and proceed in a systematic manner. With proper cam timing, fuel pressure, ignition, and injectors firing, it should start. The 360 Challenge cars sometimes do not start on all 8, if it doesn't clear its throat (on its own) within a few seconds, restart starting procedure (ignition off, kill switch off). Mine does this from time to time - I never touch anything but the starter push button to start it, and I let it sit idle on its own to warm up before going on track.
Jes

 

Just asking.......

 

360 Challenge cars do not have immobilizers, alarm, even keys. See one parked and you can go drive it off...

 

David,

For P1269 I'm getting "Function Monitoring: Safety Fuel Cut-Off (Bank 2)" and in the suggested cause / remedy box "Range/Performance (plaus)"

For P1104 I'm getting "MAF Circuit HFM (Bank2)" - Low Input (min) / Check the wiring / Check Air Mass flow (between left and right) difference not more than 5kg/h / In idle, hot condition air mass flow has to be 18-25

Both codes relating to Bank 2 has to be somewhat positive in so far as it allows you to concentrate on that bank.

Have you started the engine with the covers off the air boxes so you can witness the operation in real time of the main throttle body valves? Maybe not functional on one side?

As I said before, the loom which supplies spark and injector for bank 2 should be connected to the throttle and MAF on the opposite side. I don't know whether or not the code therefor indicates a problem with the right hand side throttle/MAF but suspect that it does.

Anyone any idea why and when Safety Fuel Cut-Off (Bank 2) is activated? Immediately I think of the "Slow Down" functions but I guess it's not the case here as you've not mentioned that warning activating. Perhaps the knock sensor would cause this?

Ultimately one would suspect that the P1104 error is leading on to the P1269 condition and shutting down the fuel. Have you tried starting with one or both of the MAFs disconnected? If I recall correctly that would force the system to operate in open-loop and default fuel/air map.

Anyway......... some food for thought!

Best of luck! You'll get there.

 

Greg,

This morning i went into work because this problem is bugging me. I swapped the inertia switch and no change.
I also disconnected both MAFs and no change also. I have not checked to see if different codes have appeared but am growing increasingly convinced it is an electrical wiring problem.

Try again Monday

 

Wow! you got a real nutbuster there. Let us know what it turns out to be. The obvious parts have been thrown at it. Seems like smart to start from the very beginning because recent past history is not helping you diagnosis this. Is there even a remote possiblity that the owner on track and pissed, got fuel sputtering before the car died and ran out of gas and then "foot to the floor" over reved the motor and slipped a belt? I knew this guy once who overreved on his heel toe downshift. He swore he never did that but his failures were suspicious.