Spyder 1998 Eclipse Spyder GS not staying running

[Lynxandlunar24]

Bought a 1998 Eclipse Spyder GS 2.4l SOHC about a year ago it had thrown a code for a bad crankshaft sensor. Replaced that and the balance shaft belt and reset up the timing and got it running today for about 10 minutes, when the rpm dropped and it shut off then backfired. When we reset the ECU unhooking battery it'll do the same thing and shut off then back fire shooting soot out of the exhaust. Did some reading and Google says it's probably a bad O2 sensor could it possibly be anything else?

 

[pauleyman]

Bought a 1998 Eclipse Spyder GS 2.4l SOHC about a year ago it had thrown a code for a bad crankshaft sensor. Replaced that and the balance shaft belt and reset up the timing and got it running today for about 10 minutes, when the rpm dropped and it shut off then backfired. When we reset the ECU unhooking battery it'll do the same thing and shut off then back fire shooting soot out of the exhaust. Did some reading and Google says it's probably a bad O2 sensor could it possibly be anything else?

Check the mechanical timing and make sure it's still correct.

 

[Lynxandlunar24]

Timing

I did go through it again and everything was still as it should be

 

[pauleyman]

Check the crank end play. Make sure it's not moving and hit the new crank sensor

 

[Lynxandlunar24]

Check the crank end play. Make sure it's not moving and hit the new crank sensor

Nope that's still good too

 

[pauleyman]

You mentioned you reset timing. You may have bent valves and not known it. Yes the car can start and run with slightly bent valves. Seen it first hand. I'd try and compression and leakdown test.

 

[Lynxandlunar24]

compression

We did compression test it and 1 and 3 are at 120 while 2 and 4 are at 150

 

[pauleyman]

We did compression test it and 1 and 3 are at 120 while 2 and 4 are at 150

That's possibly indicative. Leakdown will tell you for sure. Pull the valve cover also and look for issues.might be obvious.

 

[Lynxandlunar24]

I pulled the tappet cover to change the gaskets including the spark plugs gaskets and everything up top seemed To be straight

 

[pauleyman]

Leakdown should eliminate mechanical concerns. Backfire suggests mechanical issue or ignition issue to me.

 

[miliman13]

With these cars , well most cars. If it can run even for a short period I’m doubtful it’s mechanical, but I’ve been wrong plenty before.

I see it ran for 10mns before it stopped
Usually the front O2 will oscillate
(work correctly) after a short initial time interval but it’s possible it could of stopped functioning, but even then it would run rough and it’s surprising if it’s the cause of the shut down. But it shooting shoot that’s possible since it’s responsible for the optimal burn.

Pauley is correct to suggest the checking the crank sensor since unplugging it or the Cam sensor will 100% shut the engine off.

If we only focus on what you mentioned and nothing else , it’s possible that the new sensor fails with heat, this is common with electrical components, and I’m not going to pretend to know the inner workings of any sensor, I think it’s just a Hall effect / magnetic device . But they do fail.

After it dies , can you turn it back on right away? Do you have to wait sometime to get it running again ?

 

[Lynxandlunar24]

O2

I have to wait sometime to get it to run again

 

[miliman13]

I have to wait sometime to get it to run again

This is a stretch but heat up the crank sensor using a heat gun while engine is cold and see if you can replicate the no start, to test the crank sensor as the possible culprit.

 

[pauleyman]

O2 sensor will not cause a no start. ECU doesn't even look at it when engine is cold.
Watch for tach movement on a no start. Tach should twitch when trying to start. If it's completely dead something isn't feeding it. Last one did this to me it was ignition transistor failed when hot

 

[Lynxandlunar24]

Ok we did some electrical testing and the results came back that my ignition coils are weak so we're going to try to replace those next and go through what we can. I did try what y'all told me to do with the sensors and no difference was made.

 

[Lynxandlunar24]

Ok we did some electrical testing and the results came back that my ignition coils are weak so we're going to try to replace those next and go through what we can. I did try what y'all told me to do with the sensors and no difference was made.

Changed ignition coils still no different and changed air intake going to try Checking out the fuel rail and injectors cause when we started it today it ran for about 10 minutes but was running really rich then backfired with a plume of white smoke coming from the throttle body

 

[pauleyman]

Do you have any method of datlogging? Even a cheap Bluetooth dongle will work. I wouldnt throw any more parts at it.

 

[Lynxandlunar24]

Like a code reader?

 

[pauleyman]

Like a code reader?

More than that. Something that can at least read live data. If it's rich there is a reason.

 

[Lynxandlunar24]

Oki I have a Bluetooth connector I'll try data reading and I've been keeping a journal of everything put into it in my office