Just chugging along

[Desroches]

well I figured i'd put this question to you guys.

After my car warms up (its winer here) and I pull to a traffic light, my car starts to chug. Sometimes it chugs so bad that I think it will stall, so I give it gas. Then it goes right back to chugging! anybody know what the problem would be?

[mechanicaldj]

explain chugging,

you mean it starts to miss, like it's not firing on all cylinders?

[Kindred]

That sounds like what he means. The RPMs drop to a point where the car is about to stall.

[Desroches]

kindreds got it.

[mechanicaldj]

you are going to have to clean or replace your Idle Air By-pass valve.

which is located on the drivers side of the intake manifold(down low) on the fuel injected models

i suggest cleaning out the air passage first:

[Desroches]

can you direct me somehwere that will help me clean it? The haynes book only shows how to remove and install.

[mechanicaldj]

as shown in the diagram above, just pull off the the two air lines and spray some gum cutter or brake clean into the openings, sometimes easier if you pulled it off the car. but the only problem with pulling it off , you may break the coolant lines to it (not shown in the diagram above).

[Desroches]

Thank you very much! I found it today, and tomarrow I'll go and clean it

[Desroches]

I went and cleaned it today, but there is little or no difference. Here's a list of what hayne's gives. What would be the next most likely problem?

Vacuum leakage
Leaking EGR valva
Air filter clogged (already checked that)
fuel pump not delivering suffiecient fuel
leaking head gasket
timing belt and/or pulleys worn
camshaft lobes worn

[mechanicaldj]

and i forgot something,

smack the air control motor itself(on top) while idling,

does it idle smoothly?

[dude]

hey there...I am near to saskatoon also and am having the same problem...I have a fuel injected 90 festiva and discovered that if I pinch the fuel return line while it is idling that the idle picks up and the car runs normal again...I believe that the problem is the fuel regulator...it is at the back of the engine near the top just behind one of the injectors...follow the fuel lines and you'll find it...I have not replaced it yet but believe that it is the culprit...hope this helps both of us. 8)

[Desroches]

I'll have to check that out and see if that has anything to do with my problem. where near saskatoon do you live?

[dude]

I live in Langham and have a blue '90 L model. 298,000km on it and has been the most reliable vehicle ever!!! But now I am getting this same chugging at idle speed after it warms up that you are describing. I think that the fuel regulator is letting too much fuel out of the fuel rail and back into the return line to the tank and that is why when stepping on the gas it runs good again but then at idle it bogs down and wants to stall. I think that is what is going on anyway. Have to drive my truck now until I get it running properly again. Good luck to us, eh!!! 8) Why do things always go wrong only when it is cold and snowy out??? aaaaaaaarrggh!

[dude]

As it turns out, after further diagnosis, the problem for me was that the flexible ducting between the air cleaner airbox and the engine was cracked and leaking. As a result the airflow sensor, on the airbox, was giving a reading to the ECM unit that was different than the actual air volume being sucked into the engine and hence the stumbling. Computer would not compensate since the reading from the airflow sensor was accurate to what was in the airbox but different than actual. Hope this helps you. A good temp fix is duct tape around the ductwork until you can get a replacement piece. 8)

[Desroches]

It's been ef'n cold in saskatoon, and we don't have room in our garage, so I've been waiting for a semi-nice day to role around to check things out. Thanks for the advice, I hope thats the problem, would be a pretty easy fix.