94 SHO Hard to Start after Driving

[Edward Birdsall]

Need help troubleshooting a hard start problem with my 94 SHO. The car starts easily 1st thing in the AM. But after a short drive, she does not want to start easily. And at times, she will backfire. Wondering if this problem is related to a bad ignition coil or module.
Thanks, Edward

 

[zoomlater]

Pull your three digit codes using the instructions below and let us know what they are

http://web.archive.org/web/20090428090431/http://www.shophoenixproject.com/eec/eec.htm

 

[Edward Birdsall]

Thanks! Will do and share l8r today after work.

 

[rubydist]

I have had numerous cars with this type of symptom where the real issue was a fuel injector leaking down, which will flood the engine. After a longer "off" time, the gas will either evaporate or leak down into the crankcase and then it will start fine.

Next time you have that issue, put the gas pedal all the way to the floor and see if that allows it to start right up.

 

[Edward Birdsall]

Thanks Ruby. This makes sense. How do I determine which injector is leaking? Is there a quick fix without having to pull them out? My guess is I have a failed o-ring somewhere. I noticed that the car starts when hot if I quickly crank it with the ignition key. A quick turn and it will catch and fire up!

Zoom, my trouble codes are as follows:
KOEO - 212, 214, 332
KOER - 129, 167, 225
CBT - 538

 

[SHOdded]

The only "quick diag" I know of is to check the spark plug for fuel smell. There may be other indirect methods as well, such as checking resistance values on the injectors but I am not familiar.

 

[zoomlater]

The three digit codes are shown here

http://web.archive.org/web/20090429123516/http://www.shophoenixproject.com:80/eec/code3.htm

I noticed you had another thread from last year, did you try doing the things rubydist suggested? Did you clear the codes since the last discussion? Hence, did these codes come up again?

https://shoforum.com/index.php?threads/1994-sho-atx-trouble-code-help.136774/#post-1482626

 

[chrism3784]

My sho did the same shit. Would start ok when cold, when got warm, barely cranked. I would have to wait around for it to cool down before attempting to start again, and it would till warm again. Was annoying at gas stations, I had to keep it running. Did this for a few years. Turned out to be the battery cables. I replaced all stock cables with 4 gauge, ran two positives from battery, one to alternator, then one from alt to main power. Then another 4 gauge to main power. Ran 2 grounds from battery, one to chassis next to battery, and the other to the starter, then another wire from starter to another ground point near front of vehicle. Can see all the wires in the pics. Starts like a champ anytime and everytime. Of course put a 150 amp anl fuse in the two 4 ga positive wires from battery

 

[rubydist]

Thanks Ruby. This makes sense. How do I determine which injector is leaking? Is there a quick fix without having to pull them out? My guess is I have a failed o-ring somewhere. I noticed that the car starts when hot if I quickly crank it with the ignition key. A quick turn and it will catch and fire up!

Zoom, my trouble codes are as follows:
KOEO - 212, 214, 332
KOER - 129, 167, 225
CBT - 538

You should clear those codes and drive it a bit and pull them again. You may have issues with the cam sensor. A failing cam sensor causes all kinds of issues including hard to start. It may be ok cold but flaky when hot.

On the injector issue, depending on how bad it is you may get it solved by running fuel injector cleaner for several tanks in a row. I would do that.

 

[blk\blk90]

That's what I was thing ruby. Mine does the same thing op's does and my cam sensor is bad. My guess is that it fills with oil while driving and doesnt have time to drain out with quick stops but overnight it will.

Edward, does your tach act up? Sometimes works, sometimes doesnt?

 

[Edward Birdsall]

Hey Ruby, I just cleared the codes. I will report new codes tomorrow.
Blk, my tach doesn't act up. All is good in that regards. Thanks for your input.

 

[Edward Birdsall]

Update Codes: 332 (KOEO), 538 (KOER), 9 (Cylinder Balance). That's it.

 

[Bryan]

You should clear those codes and drive it a bit and pull them again. You may have issues with the cam sensor. A failing cam sensor causes all kinds of issues including hard to start. It may be ok cold but flaky when hot.

On the injector issue, depending on how bad it is you may get it solved by running fuel injector cleaner for several tanks in a row. I would do that.

I was thinking a faulty cam sensor too. My 2002 xterra had the same issue (I know different vehicle, but same problem) when cold she would start
right up, but once warm just crank and no start or a hard start. I too think it’s a cam sensor on its way out.

 

[Edward Birdsall]

Chris, thanks for the advice. I will have a look at my battery cables.
blk/blk90, YES, my tach is in fact acting up! Sometimes it works, sometimes it doesn't. Especially when I'm having difficulties starting when engine's hot. Does this mean something?

 

[rubydist]

The tach is run from the cam sensor, so an erratic tach would lead me to put in a new cam sensor asap. That will help your hard starting issue as well, if the real issue is the sensor and not the wiring to/from the sensor.