1996 Civic EX coupe w/auto, ~200k miles

Trying to get this running right. I have no service records for this vehicle. Didn't pay much for it, so I guess you get what you pay for.

Rough idle - engine shakes. Idle is around 500 rpm, i.e. ~250 too low.

Check engine light comes on and flashes while driving (but is sometimes solid while driving). The codes are:

P013 intake air temperature high voltage (this could be a fluke cause it has a cold air intake and I may have unplugged the sensor while running)

P1509 idle air control valve circuit failure

P0301, P0302, P0303, P0304 misfire in each cylinder

P1300 random misfire

Yesterday, I took the throttle body off the car and cleaned it. Took the IACV off the throttle body and cleaned it.

When I took the IACV off (this is one of those rotary ones with a 3 wire plug), I unscrewed the piece on the end opposite the plug and out popped a spring with a green plastic piece. I'm not sure I got this back together correctly, though. Is the spring supposed to force the valve shut? Cause it wasn't after I got it back together.

I checked the IACV wire harness and it showed battery voltage on the center terminal. On the IACV side, I checked resistance between terminal 1 and 2, then 2 and 3. Both were in the correct range per the Helms manual.

I also shot most of a can of carb cleaner directly into the TB while the car was running.

And after all that...it still idles rough and low.

More info:

I know low coolant or air in the system can mess up the IACV, but the radiator was topped off. I have not attempted to purge air from the system, though.

I have not checked the PCV valve.

Disconnecting the IACV sensor while the car is running causes the RPMs to jump up.

Turning on the A/C causes the RPMs to increase slightly.

The idle speed starts off around 1k or so and drops to 500. I wouldn't exactly say it "hunts" cause it settles on 500; it's not bouncing around.

The plug wires are dated 2006.

I pulled the plugs and found all NGKs. Three regular and one platinum.



Now what? Look for vacuum leaks? Replace PCV valve? Replace plugs, wires, cap, and rotor? Pray?

Thanks in advance.

 

First things first. What motor is in the car and is the right ecu paired with the motor. Before I suggest sensor replacement etc. i have to know what you're up against. You may have picked up a failed swap project or someone may have ripped out an SAFC and left the ecu wires hanging.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by civicdriverzero1 &raquo;</TD></TR><TR><TD CLASS="quote">First things first. What motor is in the car and is the right ecu paired with the motor. Before I suggest sensor replacement etc. i have to know what you're up against. You may have picked up a failed swap project or someone may have ripped out an SAFC and left the ecu wires hanging. </TD></TR></TABLE>

D16Y8 and...

 

Everything is in order there.... The ecu matches the engine and all the wires seem safe and untouched. Thats good - and bad at once. Good because you don't have to change it and bad because all those check engine codes have to be addressed one by one

 

So where would one start?

 

if you cleaned the IACV and there was no change I would say replace that first. and while your in the engine bay disconnect the batter for a while and then hook it up agai then recheck your codes. If any were a fluke and if you're running in limp mode you'll reset everything. If you still get the P013 code i'm not sure what to do about that... and the misfire codes all pretty well mean you may have a toast engine but if you get it running right again with no ticks and the codes go away you're golden. I wouldn't want you to spend money on an engine that can't be brought back from the basically dead.

 

sounds like you got your hands full, i would also replace or get a working iacv from a freind and see you can get rid of some of the codes you are throwing.
a compression check and checking for spark never hurt anyone, if you have access to a compression checker, i thought i saw somewhere where you could make a compression checker but i cant be sure

 

So where would one start?

 

your plugs are rich. i would have the ignition timing checked first of all. sounds like a possible distributor problem, along with the iacv.

are you mechanically inclined? if you ahve tools and arent a total retard, ill explain to you what to check and how to check ****.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by count me out &raquo;</TD></TR><TR><TD CLASS="quote">if you ahve tools and arent a total retard, ill explain to you what to check and how to check ****.</TD></TR></TABLE>

An offer I can't refuse.

Tonight I swapped:

Plugs
Wires
Cap
+ new (OEM) rotor

From my wrecked '97 EX.

There was nothing *obviously* wrong with the plug wires I took off. They were OEM. Nothing obviously wrong in the plug wells.

The cap that came off was also OEM.

I pulled the coil and checked resistance per the Helms manual. Between the primary terminals was 1 Ohm, which is out of spec (too high). But I pulled the coil on my wrecked Civic and it measured 1 Ohm as well.

For kicks, I checked resistance on all the plug wires (the ones that came off, and the ones swapped on), and they were all in the right range.

I pulled the backup fuse and started the car. No DTCs for about 2 miles. After I got my first DTC, I went home and checked it. It was a misfire in cylinder 3.

I started the car again and drove a few more miles. Came home and this time added a DTC for a misfire in cylinder 4.

 

I went to Autozone to borrow a timing light, but they didn't have one. Didn't have a tach either. But I did get a compression tester, and the results aren't pretty:

4 - 195
3 - 0
2 - 170
1 - 170



I don't have tools to do a leak down test. Anybody on here around Cincy and know where I could get this done?

 

you can buy one or take it to a shop, i dont know of anyone that rents them.

i was going to give you some advice but, i think that motor is over with.

 

id recheck #3 just for kicks

 

Some more info:

I poured a little oil into cylinder 3 and re-checked it and the psi jumped from 0 to about 60.

On my wrecked car, I checked compression and came up with these numbers:

4 - 200
3 - 150
2 - 150
1 - 150

For each of the 150 psi cylinders, I added oil and re-ran the test. In each case, the psi jumped up after adding the oil.

So, assuming the no compression engine has a bad cylinder and/or rings, is it worth swapping this other engine to it, or would that be throwing good money after bad?

Any advice appreciated.