won't idle after engine swap?

[meohmy01]

i put a new (used) engine in my 88 accord lx. the engine is out of an 89 accord dx sedan. the engine ran fine before i swaped it. now, after the swap, it won't idle lower than 2000rpm. any ideas?

[A20A1]

you mean it's constant high idle?

Could be you forgot to connect a vacuum line or wire to one of the sensors on the rear of the intake manifold.

[A20A1]

oops never mind I reread the question...

umm check the fuel filters and ground wires

also did you remove the intake manifold when you stuck the new motor in?

did you remove the carb air box when you stuck the new motor in?

My guess is it's just a vacuum leak.

[meohmy01]

no vacum leak. i've checked them and checked them again. it ran fine before hand so i don't get it. all i did was pick everything up as an assembly and drop it in a new car. i think i had to disconnect like 6 vacum lines, all of which were reconnected.

[meohmy01]

i'm going to douse it with some carb cleaner today. it actually was idling earlier. then it started to overheat so i had to shut ti off and replace the thermostat. and when i started it back up it was back on 2000rpm. doesn't even stutter.

[shepherd79]

your choke is closing for some unknow reason.
do you still have your old engine?
try changing sensors.

[meohmy01]

ok. want to walk mw through it?

[meohmy01]

i'm going to go pick up some carb cleaner today and then do a yune up on the engine. but i've got no idea what a choke sensor is or where it can be found. this is the first carbureted vehicle i've ever worked on.

[deadlight]

I'd like it if you could figure this out, I'm in the same boat here, I'm about 1800 to 2300 on average at idle, not entirely bad fore quick launches, but horrible when you have to ride the brakes in a 20mph zone.

[meohmy01]

i doused mine in carb cleaner, i used like 16 ounces. it seems to idle now (or at least want to) but it then sometimes tried to stall. and no more fast idle for warming up. i'm going to try the fuel filters since i've replaced every other tuneup part.

[meohmy01]

it's definatley the choke though. so if anyone can help me figure this out be my guest

[mindlos]

Are you still using the same carb or did the other engine come with the manifold and carb complete?

Check your choke heater electrical connection. Either you forgot to connect it or its acting up. See if it gets good voltage and current. Otherwise I would put the old carb (if there is one) back on and see what happens then.

[meohmy01]

ok i didn't forget anything. i've done plenty of fuel injected swaps but this one is such a pain in the ass. everything is connected. the choke is like stuck and i have to manualy move it with a screw drive. that's how i got it to idle (sort of). as far as the other carb, that engine i beat into the ground and i don't even want to attempt to salvage anyting off of it.

[meohmy01]

and one more thing. when it had the lx motor in it, even though it was in pretty poor condition i could spin the tires with ease. witht he dx motor in it you punch the gas and drop the clutch and it's almost like it goes "huh?"

[A20A1]

try and move the throttle by hand and see it that releases the choke... instead of forcing it open.

[meohmy01]

ok. not sure if this is the problem, but the square thing that covers up one of the holes in the carburetor barrels is like stuck in the wide open possition. on the other engine it stays closed and if you open it it sprnings back. on the good engine it stays open and if you try to close it it springs back. what's wrong with it? another thing i noticed is that in the round barrel the gas kind of dribbles int here when you rev it while it sprays in in the other one. and i'm not sure what the thing at the bottom of the barrel is, but the one towards the front of the car is always closed. not sure if it's suppose to be that way or not.

i'm sorry about this post but i know absolutley nothing about carbs. any help would be appreciated. i'd liek to be able to drive this car

[mindlos]

You are probably talking about the choke flap in the primary barrel (square thing/flap). Here is how it goes: When the engine is cold and the accelerator is pushed it engages some cam and snaps the choke closed (via some linkage). That way the engine sucks less air and more fuel to run very rich. This is necessary for smooth idle when cold (to get enough vapor). That choke slowly opens as the choke heater heats up a bimetal spring until it opens fully in a few minutes or so, or when warm enough. Cold = closed, warm = wide open. I dont really understand which one you are saying is stuck open and which is closed. Please clarify and do mention which is hot/cold (assuming the hot one is the one in your car after running a bit).

The secondary barrel (round and towards the front) throttle must always be closed until certain rpms and load. It is opened by the vacuum in the primary barrel. As for the dribbling I do not know coz I have never paid attention to mine. But I did notice even when closed the secondary throttle still has a slight gap which may cause the dribbling. Dont quote me.

When you rev the engine there is an accelerator pump diagphram that streams fuel into the primary barrel to compensate for a sudden lean condition. However that is momentary and after that if you maintain open throttle the fuel should be coming through the venturi (hourglass things in the middle of the barrels).

[A20A1]

Well the part that sprays and or dribbles gas is the booster venturi... make sure the booster venturi is tight... like it doesn't slide around when you poke at it with your finger.
At the bottom of the barrels is the throttle plates... the secondary barrel is usually closed cause there is not enough venturi vacuum @ idle to open it up. Also the square flap that covers the primary barrel is the choke plate.

Also if the idle speeds and throttle positions are different, that could be the reason why one booster venturi sprays on one of your carbs and the other one only dribbles.

[mindlos]

so is the spraying vs dribbling a primary vs secondary on one carb thing or one carb vs another?

[A20A1]

Mindlos help meeee... my internet is like 15 years behind... like it no longer is in sync lol I'm typing and I have to wait 30 seconds to a minuet for the text to appear. this is madness. complete and utter madness. :D

[mindlos]

Serious? Either you are on dialup or you got a slow ass computer. :D

[A20A1]

No my comuter is fine an my programs run fine except for internet explorer... I might download netscape just to see if it works. And for some reasom I have to refresh the page once to get my post to appear on the collumn next to the topic and once more after I click on the topic to read my post... all this refreshing is driving me nuts...

I think he ment 2 seperate carbs on different motors.

[mindlos]

Something like that has happened to me. If you notice it every time you are completing forms on any website and running windows9X then you may have corrupt protected storage files, which is a well known random problem.

Ckeck this knowledge base article http://support.microsoft.com/default.aspx?scid=kb;en-us;251787.

It happened to me more than once and I had varied success fixing it in any way other than turning off protected storage. Then you may not have autocomplete and all that crap.

[A20A1]

I spent the rest of the day downloading Netscape 7.1 and everything is fine.
It looks nicer then IE anyways... but thanks for the help. Is that orc from Warcraft?

[mindlos]

Warcraft indeed. I'm currently playing Warcraft III: The Frozen Throne. So meohmy01, do let us know. Seems like this would have been simple to fix.

[meohmy01]

i'm sorry but there's just to much to follow for my simple brain. i decided to take the carb from the bad engine apart because i was bored. that's the carb where the squaer thing seems to work right. coild the black think that's rivited to the side of the carb be my probem? it's got a wire going to the back of the manifold. not sure what it is, it has some coil thing inside

[mindlos]

Thats the choke heater wire I was talking about that heats up a bimetal spring and causes the choke flap to open pregressively.
The black thing is also the fast idle with the fast idle unloader right next to it (on the same module really).

[meohmy01]

well i replaced that one witht he one from the other carb, and the flap thing operates the way it's suppose to now. however it doesn't run any better. actually right now the car won't start and i really don't know why. i am so sick of this piece of shit

[A20A1]

All I can say is go over everything again... also check the battery power.

Have you thought about removing the vacuum lines on the air cleaner, so you can remove the aircleaner and fiddle with the carb and see the float level to make sure you're getting gas, it also makes it easier to test for leaks since you gain access to all the vacum lines.

http://www.3geez.com/showthread.php?s=&threadid=12208

[meohmy01]

i fucked around wqith it for a couple hours. scrubbed it as clean as i could get it. replaced a few vacum lines with hose from the old engine, and somehow got it to idle. however there are still a couple quirks. it has a pretty bad skip to it. it also idles rough. besides the skp it seems to run smoothly but it stillo vibrates liek a bitch. today i had to replace the front engine mount because the other one like self destructed for whatever reason.

one more thing, do you really think i'm that stupid? your last post kind of made me laugh, asking if i had thought about removing the air box to check it out. i did the engine swap, i think i have the common sense to take off the air box and fiddle with the carburetor.

[zero.counter]

Originally posted by meohmy01
ione more thing, do you really think i'm that stupid? your last post kind of made me laugh, asking if i had thought about removing the air box to check it out. i did the engine swap, i think i have the common sense to take off the air box and fiddle with the carburetor.
Glad you have it with a closer to normal idle. Good job on the swap. I don't think he meant it that way, he was just stating the process of elimination steps. It's cool man. :smokin: