1992 v12 coupe

Just had the car put on a nice night in Miami and after coming off the highway onto side road the engine stalled and won’t restart. It turns over and attempts to start but immediately stalls. So I must be getting fuel and spark. Fuel pump and filter have been done right within the past 6 mins. And ignition wires plugs cap and rotor were done just before that. Have been having good luck for a while now. What would make it shut down upon starting?

 

After letting it set for an hour I went to try again and had the same result. It had cooled somewhat but not totally in that amount of time. Temperature has been very solidly under control for the past month since changing the thermostats. Everything has been goin so smoothly I almost began to trust the car...

Anyway, looking for ideas as to where to begin besides having it hauled 60 miles to the shop I trust.

 

I would look into something common for all cylinders. Fuel pump, central wire to spark plugs, distributor cap... the fact they got replaced recently is not a guarantee they work. Check that they are all in place and connections didn't shake loose.

 

Hi gccch

1992 V12

First Question: What type of Fuel Rail do you have on your Car?

Is it the earlier one with the Rubber Hoses to the Injectors or the later type where the Injectors connect directly to the Fuel Rail?

If you have the later type: The Fuel Pressure Regulator is somewhere behind the Splash Guard of the Front Wing (I think?) Greg would know and have a diagram

Since the FPR (Fuel Pressure Regulator) for the Later Fuel Rail is hidden out sight, there is a possibility that the internal diaphragm may be on the way out and the FPR may never have been changed during the life of the Car

Can you hear the Fuel Pump run for about 3 Seconds (every time you turn the ignition on and off)

If not then it could be the Fuel Pump Relay (easy fix) and or the Main Relay (easy fix)

Have you tried putting 12v directly on the Fuel Pump?

Can you get a Spark Plug out, is it Wet or Dry?

 

I have the later fuel rail. But my FPR is on the outgoing end of the rail in front on the passenger side. I suppose that could be the issue. I was not able to confirm 100% if the fuel pump was cycling before starting,, however I have encountered this several times and the result is a cranking engine with no attempt to start (no fuel). Then changing the fuel pump relay has immediately solved that. So this is much different in that the car will start running as usual but immediately die off. So FPR would make sense to me... not enough fuel to keep it running?

What is the Main Relay???

I'm going to have to have it towed this morning to a shop as I can't leave it in the road and I don't have much facilities anymore... also why the car is for sale.

It really has been doing so good lately...

 

Hi gccch

I just typed out a long reply but as soon as I put a Photo up the whole lot disappeared!

So the Shortened Version is:

Try and get your Car Towed Home if you can, or you could be at the mercy of the 'Shop' you take it to who may charge a premium for the Parts

If you can't hear the Fuel Pump running for about 3 Seconds, every time you turn the Ignition Key ON and OFF, then take the Wires off the Fuel Pump and then connect those Wires to a Test Light

Then every time that you turn the Ignition ON and OFF the Test Light should light for 3 Seconds

If that doesn't happen, then either the Fuel Pump Relay or the Main Relay may need Replacing as BOTH those Relays need to Work or else the Fuel Pump Relay will Not Work

These Relays are NOT Interchangeable and even experimenting with that Could blow the Main Relay which is also fitted with a Diode

The Main Relay is Next to the Fuel Pump Relay

The Main Relay is in The RED Holder with the RED Stripe and The Fuel Pump Relay is next to it in the Black Holder

Both Relays need to be working or the Fuel Pump Relay won't work (as has been said)

These Relays are behind a Plastic Cover by the Support Strut in the Boot/Trunk

Once you know that the Relays and the Fuel Pump are Working OK

Suspect Number2 is the FPR Fuel Pressure Regulator (only one on your Car with that later Fuel Rail) if the diaphragm inside that is leaking, then it may just build up enough Fuel Pressure to get the Engine Started

But if it cannot sustain Fuel Pressure then the Engine could die

Not mega expensive to replace and easily done yourself around $40 and well worth doing anyway, as they don't last forever

In the UK there is a 'Hack' where you can join a Breakdown Service, the Moment you Break Down rather than sign up to something you may never need, although they do charge you a Premium unless 24 hours have elapsed

But even so I would still try and get her home if I were you, as a 'Shop' could Cost you a fortune for what could be a very simple repair

 

Man that sucks, I'm with OB get it home, and check it out. It should be fairly easy to fix. Since it try's to start then stalls. You have to have three things to run. Compression, Air / Fuel, and Ignition. If anyone of the three are weak you will have issues. Give it a shot, the guy's here will guide you through it until it's fixed. Good Luck.

Jack

 

Thanks guys. I really don't have the facility or alternative transportation at the moment so I'm going to let this shop deal with it. It could be the relays but i highly doubt since I have been dealing with them intermittently (corroded terminals from the trunk leak, swapping them with another, always gets it pumping) But this failure is totally different. When the relays are acting up it just cranks with no ignition. This time ignition hits every time within the normal starting time (a second or two of cranking). Then as soon as you get the "signal" to release the key it putters out. I'm thinking FPR all the way but we'll see...

 

Hi gccch

Just thought of something else that it could be!

After Many Cups of Tea and Multiple 'Jammy Dodgers' I'm starting to think that the Problem is all down to the Ignition Switch, which I believe is somehow connected to the working of the Fuel Pump

Should be fairly easy for an Auto Electrician to Test, maybe something just needs a bit of a clean, so that's what I would suggest you ask the 'Shop' to Check Out first

But just for Fun before you do any of that, Check the Fuel Pump Cut Out Switch just to see if it has tripped out

Stranger things have happened, so Its gotta be worth a Shot!

 

My 93 4.0 did that, and it was the crank sensor. Not saying it's your problem, but it was mine

 

The shop has found the connector going into the fuel tank has some overheated pins. He says this is the issue - no fuel pressure. Pump has been replaced recently so it would be very doubtful that the Bosch pump went bad. Power is getting to the pump connector. So we need to replace that connector at the top of the tank.

 

Makes sense that it isn't getting enough fuel from a pump that can't draw as much current as it should through the connector. Hopefully a clean/repair of the connector gets you going again.

 

Hopefully that'll be the fix! Shouldn't be super expensive luckily!