Hi, me again.

So the 2m4 is partially working, I mean, I can start and go from here to there BUT if I drive over bumps (the streets from my town are sh*t) I erratically get chech engine light and when the light is ON (usually blinking like crazy) the engine start to die, but if I give it some gas I managed to keep it running.

Now, other thing I notice is I start the engine without give it gas it goes shout down instantly, if I start the engine and keep the revs a little high, the engine keeps running.

So I thing the problem is some poor contact on the lines where the fuel pump is connected, maybe a pigtail?

Btw, when the engine on, the check engine light gives me no codes, only when I drive over bumps.

The engine light works also. (Always on with key on, engine off)

What do you suggest to start checking?

Start by checking all of your grounds. Look under the hood and in the engine bay. Make sure they are clean, free from rust, and tight. If bumps are causing electrical problems you have a bad connection somewhere. Try moving the wire harnesses around while the engine is running, if a malfunction occurs this can help pinpoint a specific area to look.

My guess is a that you have an 84 and you have a loose nut on the positive battery cable at the starter.

If you are 85+ check the nuts on the power distribution posts located under C500 (big electrical connector near the battery)

Both of these are live with the battery connected so make sure you disconnect the battery before you put a wrench on them.

Also electrical problems do not copulate.

I have nothing except,

"I would rather pound my balls flat with a sledge hammer than hunt down an electrical problem."

Favorite saying

Steve

------------------
Technology is great when it works,
and one big pain in the ass when it doesn't



Detroit iron rules all the rest are just toys.

quote Originally posted by 84fiero123: I have nothing except, "I would rather pound my balls flat with a sledge hammer than hunt down an electrical problem." Favorite saying Steve

Going to need copious amounts of alcohol to get that image out of my head, Steve

Definitely sounds like a loose connection. Fiero's seem to have issues with loose grounds, so that would be good place to start.

quote Originally posted by phonedawgz: My guess is a that you have an 84 and you have a loose nut on the positive battery cable at the starter. If you are 85+ check the nuts on the power distribution posts located under C500 (big electrical connector near the battery) Both of these are live with the battery connected so make sure you disconnect the battery before you put a wrench on them. Also electrical problems do not copulate.

Crap, you was right man, a loose nut at the starter, now the fiero is not shouting down anymore, btw it's an 86

Also the check engine light when driving over bumps persist so I will check every damn connector.

Is there a way to get a code in real time?

Thanks.

quote Originally posted by Neils88: Going to need copious amounts of alcohol to get that image out of my head, Steve

Glad I could help you start the weekend off early. by the way I made a T shirt that says something like that only about rear drum brakes.

quote Originally posted by alejandrissimo: Crap, you was right man, a loose nut at the starter, now the fiero is not shouting down anymore, btw it's an 86 Also the check engine light when driving over bumps persist so I will check every damn connector. Is there a way to get a code in real time? Thanks.

clear the codes, by disconnecting the battery for a few min, it may have been caused by the loose battery terminal and may never start again.

Steve

[This message has been edited by 84fiero123 (edited 05-24-2014).]

Make sure that the spark plug wires are not touching the exhaust manifold. Look at the spark plug wires and if you see an melting on the wires. I had mine ground against the exhaust manifold and burnout my ECM.

Buy my scanner cable, use TunerPro RT and you can scan both the inputs, and the error codes in real time.

http://reddevilriver.com/aldl.html

It's the 12 pin USB version you need with the Fiero.

Not in real time but you can read the codes with a paperclip