Engine shut off while driving?

[corax]

I do have a fuel pump cut off (Master Lock Starter Sentry) but it has never given me any problems.

bypass the relay, or just replace it (normally cost <$5 at any Radioshack). It's a cheap relay and I've seen them go bad in a circuit disable scenario as is common in alarms. They are normally wired so that the alarm will activate the relay and pull the contact away from 87a so the circuit goes open. If it's a standard "bosch" type relay, pull it out of the connector and jumper pins 30 and 87a.
- on left is an unactivated relay, no current flow through the coil - on right is the standard pin-out for a relay

I had a 1996 Lexus (Toyota) that would shut down suddenly, especially on hot days. It became intermittent on start up too. Turned out to be a crankshaft sensor and a camshaft sensor messing up the the ECM. No codes were ever detected.

That would actually be my first stop if the thing is shutting of very suddenly without any sputtering at all. I've seen that on several different brands - the ECU loses the crank sensor (which triggers ignition) and just thinks the engine was shut off, there's no logic that makes the ECU determine a fault by seeing that the key wasn't turned off.

 

[Zam15]

bypass the relay, or just replace it (normally cost <$5 at any Radioshack). It's a cheap relay and I've seen them go bad in a circuit disable scenario as is common in alarms. They are normally wired so that the alarm will activate the relay and pull the contact away from 87a so the circuit goes open. If it's a standard "bosch" type relay, pull it out of the connector and jumper pins 30 and 87a.
- on left is an unactivated relay, no current flow through the coil - on right is the standard pin-out for a relay

I will give that a try if it happens again. I still carry the stock relay JIC this one went bad.

 

[Zam15]

bypass the relay, or just replace it (normally cost <$5 at any Radioshack). It's a cheap relay and I've seen them go bad in a circuit disable scenario as is common in alarms. They are normally wired so that the alarm will activate the relay and pull the contact away from 87a so the circuit goes open. If it's a standard "bosch" type relay, pull it out of the connector and jumper pins 30 and 87a.
- on left is an unactivated relay, no current flow through the coil - on right is the standard pin-out for a relay

That would actually be my first stop if the thing is shutting of very suddenly without any sputtering at all. I've seen that on several different brands - the ECU loses the crank sensor (which triggers ignition) and just thinks the engine was shut off, there's no logic that makes the ECU determine a fault by seeing that the key wasn't turned off.

Replaced with the stock relay and it has been running fine for the last few day! :elkgrin: Just hope it says that way :snorkel: Thanks for the help! I'll let you know if anything changes.

 

[corax]

It was one of those relays with the tiny radio circuit in it, wasn't it? Like this:

I've seen NUMEROUS of those things fail - cheap China junk. (BTW, on the wholesale side they only cost $18 for the 2 remotes and relay - I've seen places charge hundreds for the product + install).

Anyway, hope that took care of it for you.

 

[Zam15]

It was one of those relays with the tiny radio circuit in it, wasn't it? Like this:

I've seen NUMEROUS of those things fail - cheap China junk. (BTW, on the wholesale side they only cost $18 for the 2 remotes and relay - I've seen places charge hundreds for the product + install).

Anyway, hope that took care of it for you.

Yup, exactly that... I'll replace it with something better....

Installed it myself and got it for cheap. Just another layer of protection..