Accord 99 1.8 ls vtec, I have problem with rpm in neutral, around 600rpm. I change spark plugs around two months and here the result, one seems have problems with fuel injector or spark? Now I change spark plugs ngk iridium, and I have the same problem.

hear opinions !!





Look good the three spark plugs on the left?

 

Have you checked for any stored codes?
Verified resistance of the spark plug wire?
Verified compression in all cylinders is equal or within spec?
Verified fuel injector is not leaking?
If the compression and spark plug wires check out fine, try moving the injector to a different poition, and see if the problem follows the fuel injector.

 

1.8L LS V swapped into a 6th gen Accord.....

Did you do the swap?

Condition of engine before swap?

Wiring/distributor conversion used, F or B?

What engine management system are you running, stock or chipped ECU?

Any check engine light/stored codes?

 

1.8i LS is the European Accord, a CG/CH chassis with F18A3 engine.

 

oh right....keep forgetting that there are a few European chassis owners on board. I saw LS VTEC and just assumed the worst!....lol

Forget what I said

 

Thanks for the answers!!

Ignition wire resistance 8k, 20k, 40k, 11k but why only one spark plug appear bad. In service manual says 25k, this is not the problem?

I don't have tools to measure cylinders pressure, injectors appear clean, outwardly...


I'm trying to buy ignition wire and doesn't appear wire resistance... can put something better?

I'll wait a few days with new plugs to see which gets more black.

PD: Iridium spark plugs need adjust gap?

 

Not really. Ngk iridium and nippodenso come pregapped close to spec.
How are the plug wires? Burning any oil?

 

I think so, but finally increase gap to 1.1mm. Plug wires are clean, if you mean to spark plug connectors inside the engine

Now the question is to replace the wires, if the resistance affects to spark plug life or electronic circuits to high voltage.

 

Here iridium spark plug status, the problem is in shorter cable (8k) sometimes did not measure, it will be broken. I order new cables, waiting.

 

Iridium Denso's always spec for me. Gap should be 1mm IIRC.
Verify the resistance of the plug wires when they are hot, as in get the engine up to temp, turn off the engine, pull the wires and check the resistance of each one.
A Cold check may show them fine or within spec, but a hot check will show how they are actually.
Kind of a hard thing to do with certain electrical components.

 

One thousand years later....

Bad cylinder have around 150 psi like others, so not have problem with pressure



Here we have one of good cylinder



Here bad cylinder, it's looks like problem with piston knocking (I don't know the correct name) or it is excess coal?

 

I have low pressure on all cylinders, need to be around 205 psi, the black spark plug is not pressure problem... only happens with one

I clean injectors inside, outside, use decabonizer product and they were not obstructed y changed spark plugs and one keep going black a

MAD_MIKE I will test wire resistance when the motor is hot, spark plug wires are new... you think the problem appears with temperature? I go to garage....

 

how about the cap and rotor, have they been replaced ?

 

Cap ? Rotor you refer to distributor? I opened it looks good, spark plug have good spark, only inside have a bit oil. If I change distributor I want to put electronic, I need to look more information about replace it.

I want to change injector seal ring and I look better with endoscope inside the valves.

Wire have 9.16k cold and 8.75k hot resistance.

 

Terminal on the cap may be damaged or shorting to ground/earth. Pull off the EGR manifold cover(5 bolts on manifold) and clear the ports on the intake runners and the passages in the EGR manifold. At part throttle if those passages are coked up with carbon, you will have a lean misfire at part throttle. This would cause the plug to foul as the mixture is not properly igniting.

 

Thanks MAD MIKE! I have seen cap and terminals and looks good. I disconnected EGR, I disarm it and it's dirty.
I have new collectors gaskets, this weekend I disarm admission collector to clean and look better and carbon residue.

To "digital" distributor need 4 ignition coils ?
With non-resistor spark plugs what problem I can have apart from the radio?

 

Coil on plug conversions are possible, there have been a few write ups, and Hondata has a Coil Pack Retrofit kit. https://www.hondata.com/coil-pack-retrofit
This conversion does improve ignition quite a bit.
The noise caused by the non-resistor plugs will cause problems with the ECU as well. There are no benefits to using non-resistor plugs with the PGM-FI. You may actually damage the ECU from the interference. Coil on Plug conversion will be well worth it alone, just keep using quality resistor type plugs, the aforementioned Iridium TT plugs have always worked fine for me.

#17 in the below image is the lower plate that is coated. It just needs to be cleaned, do not scratch or scrape the surface as this will damage the sealing surface.
#16 is the EGR manifold and has passages that will become carbon fouled, a flat head screwdriver is very effective at clearing out the passages. Clear out the corresponding ports in the intake manifold #11.

 

Thanks MAD MIKE!

I've got a question and a problem, it's possible to extract out the admission manifold with the motor inside the car?

 

Looking valves I found this situation, couples move at the same time, right? I have problem with camshaft ? This valves are from black spark plug cylinder.


This time I cleaned egr port, only I haved problem with screws to put them, they were butter



Black part it's a piston and grey it's a burned carbon ?

 

yes thats a major problem, take the valve cover off and see if the valve keepers came off

 

Thanks holmesnmanny, next weekend I remove valve cover to look

I have other intermittent problem with rpm, has ocurred several times. Neutral RPM are in around 650rpm but when accelerates and lift throttle, the rpm goes down around 150rpm and then stabilizes.


Trying to remove admission manifold I broken one sensor,I found information about it and his name is knock sensor, I go to buy one new. My rpm problem has ocurred before and after broke this sensor, when I finished to put manifold again I started the motor and all it worked ok, but to the next day the rpm problem started happening and motor light turns on (light appears on this ocassion)

 

yes, you just need to replace the knock sensor too, as it's likely causing the check engine light to come on, you can pull the code to confirm

but that valve damage is going to be the cause of the low idle and hesitation

 

Your 1.8 VTEC engine is a variant of the F22B1 we have here in the USA.
It is normal for the valves to be at different lift heights when VTEC is not engaged. This promotes swirl and tumble for the air charge which provides better power at lower rpm, one valve uses the low lift lobe the other the mid lift lobe. When VTEC is activated then both valves will be opened at the same time and same lift using the high lift lobe.

I've had the bolts for the EGR manifold bolts break. They only need to be as tight as the valve cover, ~10Nm.

Have you checked the valves are adjusted correctly? If the exhaust valve is too tight it will cause a loss of compression and a misfire, this can foul the plug.

 

I receive to next week knock sensor, so this weekend I revise valves. I need wobble extension bar to can rotate engine.

Time ago when I bought the car I had readed about VTEC system and speaks about increase valves time of aperture. Here appears like two valves work at the sime time and vtec open valves more time/deep


Here a video where one valve open more and with vtec open eqaul and more time, you talk about this right? So this valve position are fine?


When I cheked cylinder preasure I thought valve position was fine, this weekend I check it.

Thanks!

 

Yeah, somehow I missed the vtec part and it's safe to assume that this isn't a three stage vtec engine.