redwood_usa

iTrader: (4)

My car starts and runs well from cold - But if I go a long ways and park for a little while it starts missing badly when I restart it. Or if I go a short ways and park in the hot sun (texas in july), it does the same . Any one with some ideas.??

dafiremaster

have a mechanic throw a timing light on it. Also other things to check would be the spark plugs/ignition system. or a vapor lock issue.

redwood_usa

iTrader: (4)

I initially thought that it was a vapor lock, but all the reading material on the net says that vapor lock is a thing of the past with fuel injection engines. Could a failed gas cap do this ?

Greeny

iTrader: (43)

You have got to be joking? right?

Greeny

iTrader: (43)

Have you done a tune up recently?

dafiremaster

Fuel injection has cut down on the vapor lock problem, but it can still happen. How long has it been since you've changed your fuel filter? also you might have some water in the fuel lines. My car has a similar problem, which i've not yet figured out. I can only get it do to it sporatically. It got to the point where i hadnt drove the car at all and my fire department got a code red shooting call. Well it ran like crap. trying to get to the call, and then died on me at the scene. Boy... that was an interesting day. I'm hoping the problem shows back up in the summer, so i can take care of it. Though, with future plans to the car, that problem may not be an issue any more.


I've never had any experience with a failed gas cap, but i've been told before that fuel injected cars run like crap without a gas cap on. so i suppose that could be a problem.

dafiremaster

No... i'm not joking. Timing can cause an engine to miss. Though typically when the engine is cold. I've seen cases where it affected the engine when it got hot.

If the engine is missing, the ignition system is a no brainer to look at.

redwood_usa

iTrader: (4)

Assuming I have some water in the fuel lines - how do I get rid of it ? I did a tune up of everything else about 3 months before this problem started. New sparks, wires, air filter, fuel filter, cap.

Greeny

iTrader: (43)

I was referring to the vapor lock theory dude..Welcome to 1985..


On fuel injected cars the gas is constantly circulating from the tank, through the system and back to the tank. The fuel does not stay still long enough to get so hot that it begins to vaporize.

internetautomar

iTrader: (30)

There is no vapor lock because the fuel is under pressure from the time it leaves the tank.
Vapor lock occurs only on vehicles without an in tank pump.

dafiremaster

It still can happen! water in the lines, If the fuel filter is clogged, under heat it will produce a similar type occurance.

To get water out of the lines, run the tank about empty. Put 3-4 bottles of isopropyl alcohol in it and run it till it dies.

Greeny

iTrader: (43)

Quick! Logout.....

internetautomar

iTrader: (30)

uh huh, let me guess you went to mechanics school right?

goon9

iTrader: (13)

It's called A-tech skool now right? Just goes to show that some shops still pay more for ppl with experiance than schooling.

Anyway. If there was moisture in the line(which I think is bs because Internetautomart is correct). But IF, it would run like crap ALL the time. It's only doing this after warm up.

Knock sensor? I know they tend to cause problems after warm up.


And about timing. I've set my way retared and advanced, and never missed. The only time was when I was 180 off.

When I ran into a problem like this before, I changed my cap, rotor, plugs and that solved the problem.

Alex_V

Test your injectors and run some marvel mystery oil and a bottle of techron additive with 1/4 of gas or less. If you tuned up your cap and rotor recently any way.

~Alex

redwood_usa

iTrader: (4)

Solved the problem. It was the oxygen sensor.

Greeny

iTrader: (43)

The sensor was vapor locked..

redwood_usa

iTrader: (4)

:-)) Aparently the sensor was not working for a long time and the engine was running really lean when hot ? It was a lean misfire. The battery must have been disconnected for some service after the sensor failed and the ECM never learnt eh right mix for a really hot texas summer.