Car runs rough then dies

[wtfklf]

I have an 82 malibu with a 5.3 ls swap. I was heading home the other day and it started running rough and throttle wouldn't work. Then it cleared up and was fine the rest of the way home. While idling it will start running rough till it dies and throttle does nothing. There are no codes and 60psi fuel pressure. Anybody got any ideas?

 

[wtfklf]

It also has a stock gen 3 pcm and an ebay swap harness.

 

[78Delta88]

Common problem with IAC valve when it starts going out. Intermittent issue, doesn't always throw a code into OBDII.

Find where it is remove it, spray it with carb cleaner and put it back in.

One of the idiosyncrasies with drivability problems, is usually the worst symptoms are caused by the most minor cause.

If the car is running absolutely fine and all of a sudden starts acting bad..., look for loose or disconnected connectors, failed sensors, worn, burnt or dirty solenoid/motor actuated parts.

So, some of the other things to look at in your case, are: EGR, Fuel Injectors, one or more coils, loose or dirty connection to ECM, vacuum leaks, weak battery, alternator regulator not maintaining at low rpm...

Try the IAC it's fairly simple, but basically need to run a scan tool on your setup, or you start chasing your tail.

 

[wtfklf]

I swapped iac with a good one and it still does it. All I have is a cheapo code reader so it really doesn't help much. The old lady's uncle is a mechanic, so I'm gonna see if he has a good scan tool that will show us live data.

 

[78Delta88]

Hmmm... Wonder if issue is in eBay harness wiring quality.

Hopefully scan will show you something.

 

[wtfklf]

I kinda wondered that, but from what I have seen people have pretty good luck with them. The swap has around 150 miles on it now and was 75% done when I bought it. So it's had several bugs to work out.

 

[WAGOOON]

Have a peek at the crank sensor and it’s wires & connector. See if there’s any metal sticking to the sensor

 

[78Delta88]

Another item to check would be throttle position sensor. Usually when those go bad, it will set a code and go into Limpy, but might be something to look at.

 

[wtfklf]

Cam sensor was loose and had a port under the map sensor not plugged on intake.

 

[78Delta88]

So, all good again??