Dies while idling

[TBR]

So the Prelude has taken to just turning off while idling. No drama or anything, the revs just go to zero. If I catch it soon enough a touch to the gas brings it back, otherwise I have to turn the key. Hasn't really been a big issue, till I was making a tight turn today with the clutch in (so the engine was idling). The engined turned off and the power steering went with it. I was going slow so it wasn't really a big issue even then, but under the right circumstances it could be a problem. Any ideas as to what this might be?

[ifcar]

The Escort did this in its final days: it idled too low, to the point where it would sometimes just stall out. However, I got rid of it rather than bother trying to solve the problem, so I can't actually help. Just thought I'd share.

[TBR]

Well I really appreciate that.

Other than the damn A/C control panel and the random oil light coming on this is the only problem with the Prelude right now. It runs real good.

[TBR]

Note- when it does it and I catch it it'll do it again if I let off the gas immediately afterwards. However, if I catch it then drive for a while it will idle fine at the next light.

[Secret Chimp]

Considering how many miles your chassis has, it might be the fuel filter preventing proper fuel pressure. An easy thing to do is to remove your intake up to the throttle body and make sure the idle ports aren't all gummed up with carbon (B-12 Chemtool is great for cleaning that stuff)

Edit: your idle control valve motor can also get gummed up. If this engine is an F-series the bolts are a huge pain to get off, but you can basically soak the thing in B-12 and clean it out and reset your idle.

[The Pirate]

Does it do when the engine is warm or cold?  Or both?

[TBR]

Does it do when the engine is warm or cold?  Or both?

Both, but maybe more frequently when the engine is cold.

[TBR]

Considering how many miles your chassis has, it might be the fuel filter preventing proper fuel pressure. An easy thing to do is to remove your intake up to the throttle body and make sure the idle ports aren't all gummed up with carbon (B-12 Chemtool is great for cleaning that stuff)

Edit: your idle control valve motor can also get gummed up. If this engine is an F-series the bolts are a huge pain to get off, but you can basically soak the thing in B-12 and clean it out and reset your idle.

How do I tell where the idle ports are?

Also, it's a H23A1

[Secret Chimp]

How do I tell where the idle ports are?

Also, it's a H23A1

When you take off your big plastic intake tubey thing to get to the throttle body, you'll see some holes bored into the main block of the throttle body. One is going to be near the top for the idle speed adjustment screw, there are a few really tiny ones, and if you hold open the throttle plate you'll see their outlets as well as both ports for the IACV. They're all on the front surface of the body surrounding the plate or just behind the plate.
Considering that it's worse when it's cold, a good guess would be that your IACV might be sticking, but before you crack that off just clean everything around the throttle body, it's an easy 20 minute job.

[TBR]

What should I clean it out with?

[TBR]

To make sure there isn't something vastly different with the Prelude, here's the throttle body/fuel injection system:

[Raza]

This happened to my friend's Civic before he got rid of it.  Your fuel port has become gummed up due to using dirty gasoline.  What you want to do is put it in idle and floor it for about two to three hours.  He used a cinderblock to keep the pedal pressed.  The constant revving will clean it out, and it should completely solve your problem.


Also, weren't you looking for an excuse to replace your car?

[TBR]

It has to be over $1500 or so in order to be an excuse.

[TBR]

What should I clean it out with?

After rereading your first post, I suppose B12 Chemtool would be the correct answer. But, how do I use it?

[Secret Chimp]

After rereading your first post, I suppose B12 Chemtool would be the correct answer. But, how do I use it?

You spray it. Use the red tube thing to get into the idle port and IACV ports, I recommend spraying it into a cup and using a Q-tip once you've gotten larger chunks off.
Your intake tract looks more or less the same as an F engine. Just undo the blue dealie on the very back and it will be right in front of you. Your engine won't want to run when you start it the first few times from the B-12 leaking down, don't get freaked out.

[TBR]

Okay, the stuff I got doesn't have a sprayer thing on it. Should I take it back, use it as a fuel additive (that's what the directions say), or use only the q-tip method?

[S204STi]

B12 comes in two forms, one of which is the fuel additive can that you purchased, the other is an aerosol can.  You can still use that in your fuel tank if you want, but it won't clean your throttle body like that.  Get a can of the aerosol.

Edit, you can also buy buckets of B12 for soaking parts.

[Raza]

You can't take B12 if you're pregnant though.

[Secret Chimp]

How hard is it to look at a can and figure out which is which? Cheesus Crust.

[Secret Chimp]

You know, I might have stolen the straw off of a can of WD-40, but whatever. The stuff sprays HARD and it's good to direct it instead of getting it all over the damn place.

[giant_mtb]

I used that stuff late this past summer on my car.  Holy shit did it scare me how forcefully that stuff was spraying out!

[S204STi]

You can't take B12 if you're pregnant though.

I can.

[TBR]

How hard is it to look at a can and figure out which is which? Cheesus Crust.

Well I bought it before you responded to my post about how to use it, I probably would have been more vigilant if I knew it was a spray. So, it's your fault .

I'll make this my fall break project, I am about to take my car back to freshmen parking.

[TBR]

http://preludezone.com/showpost.php?p=40206&postcount=15
Doesn't seem like it would be hard to get to. I think I'll try to clean the ports sometime this week and then Thursday I am driving a friend to catch the train (30ish miles I think), if it acts up I'll clean the ICV Friday.

[sportyaccordy]

Considering how many miles your chassis has, it might be the fuel filter preventing proper fuel pressure. An easy thing to do is to remove your intake up to the throttle body and make sure the idle ports aren't all gummed up with carbon (B-12 Chemtool is great for cleaning that stuff)

Edit: your idle control valve motor can also get gummed up. If this engine is an F-series the bolts are a huge pain to get off, but you can basically soak the thing in B-12 and clean it out and reset your idle.

I was just gonna say, it's probably your IACV. My idle dips when I hit the brakes, I just haven't got the impetus to take off the IACV and clean it. Odds are that is your problem.

I am really enjoying the JDM version of your engine BTW... hope your fix works

[TBR]

Yeah, it's a nice engine, pulls really good after 3500 or so. Just wish I could figure out why the oil light intermittently comes on (restarting the engine keeps it off for 3-4 days).

[sportyaccordy]

Yeah, it's a nice engine, pulls really good after 3500 or so. Just wish I could figure out why the oil light intermittently comes on (restarting the engine keeps it off for 3-4 days).

Watch your oil levels religiously & check for leaks down under (particularly where the engine + tranny meet)... and pray that it's not your rear main seal That will cost you big time. Might be worth it to go in there now & fix. That killed my first F22A

[TBR]

Oh it's definitely leaking, but the oil level can be perfectly between the dots and the light still goes on.

One of my previous mechanics did say the rear main seal might be leaking, but when I took it to him he never bothered to find out for sure, instead just let the car sit there as I waited. At that point I was too frustrated to actually do anything about it.

Could this cause a problem other than just the oil leaking? What kind of cost are we talking?

[3.0L V6]

Oh it's definitely leaking, but the oil level can be perfectly between the dots and the light still goes on.

One of my previous mechanics did say the rear main seal might be leaking, but when I took it to him he never bothered to find out for sure, instead just let the car sit there as I waited. At that point I was too frustrated to actually do anything about it.

Could this cause a problem other than just the oil leaking? What kind of cost are we talking?

Oil Pressure Sending unit or wiring. They usually flake out much more often than the oil pump. Oil level (within range) is unrelated.

[sportyaccordy]

Oh it's definitely leaking, but the oil level can be perfectly between the dots and the light still goes on.

One of my previous mechanics did say the rear main seal might be leaking, but when I took it to him he never bothered to find out for sure, instead just let the car sit there as I waited. At that point I was too frustrated to actually do anything about it.

Could this cause a problem other than just the oil leaking? What kind of cost are we talking?

The rear main seal is on the tranny side of the block. You have to drop the tranny to get to it... kind of a pain, but worth it over an engine replacement.