After completing a full rebuild on my buddies 99 Si, i now have an issue.

First off, its a complete stock rebuild with .25MM over p30 pistons, new Honda rings, ACL bearing kit and all machine work done at reputable shop. The head had a full valve job with installation of Ferrea valves and complete head pressure test. I then completed a valve adjustment after to clearify that also.

After starting it up it sounds great, but has a misfire. I pull #3 wire and no change, #3 is dead. I swap injectors, same thing. I swap plug and wire, same thing. I check all connectors/vaccum, same thing. I ran compression and pulled 160 or so right accross the board (motor literally has 5 minutes of running time) so my compression is there. Ive checked the voltage at the injector connector and getting full signal. So as far as i can tell, im getting fuel, ignition and compression, so it should be happening. Every other cylinder runs great and it actually runs good even with the dead cylinder, i cant wait to see how it runs after being on all 4.

I just need to get this fixed ASAP as i cannot run it much longer with a dead cylinder, ill mess that baby up and wash out the walls. I need this fixed.

Ok, throw some ideas my way, any questions or watever shoot away...

Dan

 

are you getting spark at all on #3 wire?

 

check your timing

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by yoej8 &raquo;</TD></TR><TR><TD CLASS="quote">are you getting spark at all on #3 wire?</TD></TR></TABLE>

Yes i am. At first i didnt think so cuz i could pull that wire off the plug and not get any arching from it, but i put a screwdriver in there and arched it to a ground and it sparked consistenly there, i also have full spark at the dizzy side of the wire.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by fmrprojects &raquo;</TD></TR><TR><TD CLASS="quote">check your timing</TD></TR></TABLE>

Would timing being off a little bit cause the 3 other cylinders to run perfect and just have a completely dead cylinder in #3? Im thinking i have more of a specific cylinder problem here, lying in either fuel or spark, i hope.

Dan

 

i had the same problem when i did my swap. it was my spark plug wires, i had mixed up on # 3 & 4. so check for that

 

I will do that, thanks, but wouldnt i get a dead miss in number 4 then too?

Im currently picking up a OB2 scanner from work and getting a node light to test the injector pulse. Ill post up an update after that.

Dan

 

I just finished a noid test for the injector, looks good. I put a spare spark plug in the wire and started the car then grounded the plug, i have a strong spark there. So, i have fuel and i have spark. I will be completing a leakdown test tonight, both a standard and then i will drop a screwdriver in the cylinder, locate TDC for sure, and then again, im hoping im out of time, even tho only one cylinder has the problem.

DAan

 

change your spark plug wire, it may be able to spark when you grounded the plug with the screwdriver but under pressure it might not arc.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by o5mar1 &raquo;</TD></TR><TR><TD CLASS="quote">change your spark plug wire, it may be able to spark when you grounded the plug with the screwdriver but under pressure it might not arc.</TD></TR></TABLE>

I swapped that #3 wire to the #2 cylinder and it fired perfect, so ive eliminated that possibility, thanks for chiming in tho

 

Leakdown test shows less than 5% leakdown in every cylinder, both by cranking it up and starting it at TDC then charging it up.

I still get injector pulse via the noid test and i get spark via testing it on another spark plug attached to wire and grounding it out. I get full compression at TDC of #3 and every other cylinder so i know mechanical timing is right.

Im at a total loss, help.

Dan

 

Throw some ideas out there...

 

I would check the injector spray pattern. yea u checked the pulsing and stuff but that doesnt check the spray. its has to be vaporized in order for gasoline to ignite i would check that then. and what the hell u have a new motor give it a tune up with new wires, plug... you know the deal.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 92civichatch1 &raquo;</TD></TR><TR><TD CLASS="quote">I would check the injector spray pattern. yea u checked the pulsing and stuff but that doesnt check the spray. its has to be vaporized in order for gasoline to ignite i would check that then. and what the hell u have a new motor give it a tune up with new wires, plug... you know the deal.</TD></TR></TABLE>

So your saying the spray pattern is dictated by the input signal, or the injector itself? Because i did swap out injectors with cyl#4 and the missifire stayed put.

It also has basically new wires, cap, rotor and brand new plugs. But i also swapped that out with another cars components and no change.

Enlighten me a little more on the spray pattern if u would please...thanks for the repsonse.

Dan

 

BUMP

 

Fixed

https://honda-tech.com/zerothread?id=1645129

 

Congrats, on the fix.
so what was the culprit and how did you fix it?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by yoej8 &raquo;</TD></TR><TR><TD CLASS="quote">Congrats, on the fix.
so what was the culprit and how did you fix it?</TD></TR></TABLE>

https://honda-tech.com/zerothread?id=1645129