Starts and Dies

[turbodaytona87]

So lately I've been having an issue where I'll be driving and the engine just sputters to a halt. It basically loses power to the point where it will stall within 5 seconds or so, but its not a hard shut off. When this happens, all the throttle does is change the vacuum reading.

Once it completely dies, I can usually restart it and be good to go. Three times now though, I've had a no-start issue. It will crank, then fire for maybe a second and die. Throttle does nothing. Once I turn the key off and back on it will start and run for another second, then die. So it seems like I'm getting spark and fuel, but why does it die after a second?

[cordes]

Codes? What year? What car? Mods?

[turbodaytona87]

1987 Daytona Shelby Z:

• Ported Head
• Ported Exhaust Manifold/Intake
• +40s
• ShelGame Cal
• GN Turbo
• 52mm TB
• FMIC
• Walbro 255
• TBI Cam
• AR-51s
• Aurora Wires
• Newish Cap/Rotor

[cordes]

No codes? It could be a cal issue, but I would check the codes etc. first.

[turbodaytona87]

No codes, well except 12 & 55. This is the longest its been non starting.

[turbodaytona87]

New developments: swapped in a spare coil and HEP I had. No change. I did notice that while the fuel pump primes, it does run. So after the car runs for a few seconds, I have no fuel pressure. I am looking at a new power module?

[cordes]

New developments: swapped in a spare coil and HEP I had. No change. I did notice that while the fuel pump primes, it does run. So after the car runs for a few seconds, I have no fuel pressure. I am looking at a new power module?

If you have a spare to swap in I would just for the test anyway. Have you run power from the + battery terminal to the + side of the coil to see if the pump is dead when it won't run? That energizes the Z1 circuit which fires up the pump, so if it won't run you either have a bad pump or bad wiring to it.

[turbodaytona87]

Runs if I jumper it, but if I leave it stock, it only primes. I did have it running and started with the coil jumpered, but shut it off to make the wire more secure for the drive home. Then the starter seemed to be locked up :/

[cordes]

I would check to see if you're getting power to the Z1 circuit which I believe emanates from the PM.

[turbodaytona87]

That's what I've been leaning towards. I think I have a spare, with a broken voltage regulator lol.

[cordes]

That's what I've been leaning towards. I think I have a spare, with a broken voltage regulator lol.

You could always run an external reg out of a 70's D150 or something.

[turbodaytona87]

Yeah, I've done that before, but I'd rather not hack up my harness...anymore than it is. I even have a 79 D150

[RoadWarrior222]

My van did this for a month a couple of years back and I never found out what the hell it was. I presume it was a bad connection I wiggled back into place when I was checking it out, or that I had water in the gas.

[turbodaytona87]

Its happened on plenty of different tanks of gas. Its definitely something electrical.

[turbodaytona87]

Ok, well engine is locked up as of now. It didn't turn over (no movement at all) after I was running the pump (without the engine) and tried restarting it, so I wonder if I have a bad/leaky injector and it just filled a cylinder...

[RoadWarrior222]

ruh roh... pull the plugs, expect to find coolant in it if you're feeling unlucky.

[turbodaytona87]

I honestly thinking an injector(s) got stuck open, or they leak. The car was running for about 30 seconds prior just so I could see if the fuel pump was indeed not running. I shut the engine off, attached the jumper wire to the fuel pump/coil more securely so I could at least drive the car home (about 2 miles away), then got in to start it again and the starter did nothing, just drew all the power from the battery. So I doubt a headgasket blew between it running, then me shutting it off.

I'm guessing I either have a bad PM and/or bad injectors. I've been having all sorts of weird, random problems lately. Car dieing, not starting, seatbelt light staying on for about 20 minutes of driving then going off for no reason, shitty idling, slightly increased fuel consumption (I thought this for a few weeks before this problem occurred. Wasn't bad, maybe getting 15-18mpg in the city compared to about 20),

[RoadWarrior222]

No what happens is they can leak small and the motor can cope with that amount of water until it gets to a low rpm, then it stalls, perhaps you can restart it, get the revs up, keep it burned off, BUT then when you leave it to sit when hot enough it fills up the cylinder.

[turbodaytona87]

Sorry, but I'm really doubting its a head gasket issue, I mean it was running completely fine just 30 seconds before it was locked up, and in those 30 seconds I was running the fuel pump constantly.

[RoadWarrior222]

Well if it is that, it's one hell of a leak, I figure stock injectors should flow about a tablespoon full in 30 secs full on, that's enough to "flood" it but I wouldn't think it would hydrolock a motor.