|
Post by hollandjusty on Dec 9, 2013 6:39:01 GMT -5
Hi all, I've got a problem with a 1.2 mpfi Justy I can't figure out.. When the engine idles the rpm starts to fluctuate. Especially when I turn on some electrical components (like high beam, heater, etc) Does anybody know where to look for? Ricardo
|
|
|
Post by blacklight on Dec 9, 2013 9:47:11 GMT -5
I think this "problem" is the function of the Idle-up function. The ECU monitors the high electrical loads and brings the idle up a tad to compensate with alternator output for the extended electrical load. If you still feel this is abnormal, please post a vid.
|
|
|
Post by hollandjusty on Dec 9, 2013 18:07:03 GMT -5
After 13(?) Justys I think I know for sure this is abnormal. Sometimes it even stalls! :-O
|
|
|
Post by blacklight on Dec 10, 2013 4:33:02 GMT -5
Have you checked all the vacuum hoses? They tend to get brittle and crack on cars this old, and are a cheap fix. Spray some start-helper or carb cleaner around all (ALL) vacuum hoses and listen for change in engine running sound.
|
|
|
Post by dbgear on Jan 1, 2014 21:05:55 GMT -5
I was having this problem where idle would fluctuate without any accessories running. The idle would jump back and forth between about 800rpm and 1000. When I bought my Justy the air intake tube had the broken piece that most Justys have (the vaccum tube that feeds through the top of the valve cover and then into the PCV valve). I fashioned a work-around as suggested on this site, by drilling a hole in the air intake tube and inserting a crude plumbing fitting. A few months ago I found another intake tube that was intact and just today replaced my fix-it job with the original piece. I'll need to run it more to confirm, but it seems to have taken care of that idle fluctuation.
One additional thing, when mine idles at 850 it hits a certain imbalance and the engine starts knocking around, but the engine itself is running smoothly, it's just the old engine mounts that aren't holding the engine firmly enough. This could be mistaken for a rough idle problem, but actually just worn out, hard and torn mount cushions.
I've now replaced many of the vacuum hoses, any new Justy owner should be looking to do that asap. You can replace all of them for $25, so why not just eliminate that possibility right out of the gates. The easiest way I know to do this is take your tools and car to your parts store and just replace the hoses in the parking lot. The guys at my store always come out and help because they think the Justy is cool and I'm in there all the time.
|
|
|
Post by hollandjusty on Feb 20, 2014 11:25:51 GMT -5
Any thoughts on this one? I tried all the above suggestions, but without succes..
I'm only having trouble with the engine all warmed up. Otherwise it'll run quite nice.. Can this be caused by the O2 sensor?
Ricardo
|
|
|
Post by gearheadeh on Feb 20, 2014 22:58:39 GMT -5
I do not have an idea for sure what it is. But if it was me I would change out the Engine temp sensor, the intake air sensor and then the ECU itself.
The ECU is not adjusting the fuel map correctly after it warms up! why is that? what is the engine control unit getting or not getting for info that is wrong?
|
|
|
Post by hollandjusty on Mar 1, 2014 10:55:14 GMT -5
I already changed those two sensors. So i think I'm going to try another ECU soon.
|
|