idling problems

[blindrummer]

1985 GL hatch 1800cc hitachi, 138,000 miles

on start up idles at 1500 rpm

may or may not settle at 1000rpm

after 45 min of driving he might settle at 650 rpm

new car to me and problem only started after:

oil change, air filter, pcv filter, ngk spark plugs, radiator, fuel filters

i can feel when the change back to normal happens upon downshift

its almost as if the second throttle plate stays open until its hot or something???

any thoughts

 

 

 

please

[opus]

Check that the throttle cable isnt adjusted too tight...at the carb.

[ihscout54]

Did you try pullin backwards nicely on the gas pedal (after it warms up) see if you can force it to idle?

Check vac lines make sure you didnt knock any off. Especially from the Air cleaner to the vac. switch, you just messed with that.

Choke issue, make sure when hot the choke plate is open. Also look to the linkage make sure its not biding there.

Throttle return spring, also there is a small return spring for the secondary that could have failed or popped off -that would cause some hit and miss weird idle problems.

Does it miss?

-Sam

[blindrummer]

i will try to find the trhrottle cable

i will also try to pull the pedal backwards

Sam, i'm new to the carbuerator world so i dont know where these are

one other thing to note the lid seal to the air cleaner is coming off at one spot

almost as if the seal ring was to big and it has some slack

so i will peak my head in there tommorrow and pull out my repair manual

what do you mean by does it miss

thank you for responses

[ihscout54]

Wile the engine is running if you put your ear down by the tail pipe close enough to hear it clearly, but use common sense... you should hear the engine running evenly "mumumumumumumumumumm" If you hear a "pup......pup pup...pup.....pup..pupup" mixed in there that is a missfire. Non specific to any cylindar. Along with a higher than spec. idle (may indicate a lean condition) would tell me to be searching for vac. leak or leaks.

It proves nothing though, cause if the choke was stuck on it would probably do that too along with a very rich smell.

Check your vac lines first, they probably need an inspection anyways. Every one of them should lead somewhere or be securely capped off. One of those lines on the bottom of the air cleaner goes to a thermo valve, it will screw with your idle if not connected till the car warms up a bit. (it controls the stove pipe valve).

Check your choke next. it can be adjusted. like I said befor...

The air cleaner gasket leak is going to have little effect on youre idle, but should be addressed.

Once you pull the ari cleaner off alot will be uncovered.

Let us know what happens.

-Sam