Today I was working on my car and took it out for a test drive, stomped in it and at full boost, full throttle I noticed my afr's were way off, 13.5 instead of 11.5-12 [@ wot.] I come up to stop sign and notice it now sounds like a wrx or flat four engine. It doesn't sound like its running off all four cylinders. I was messing with the boost earlier that day and it was running like a top.

I took it back to the shop and pulled the plugs and dist cap, they look fine. Swaped in another ecu [ls w basemap] on it, didn't help.

The only thing I can think of is that one of my DSM injectors may be somewhat clogged. Tomorrow I am going to swap the injectors out with another turbo car at the shop to see if this fixes the problem.

Any one have any suggestions on this? I really need this car for work monday.

Thanks for your help in advance,
Regards,
DK






..

 

start pullin plugs then injectors while its idlin...exact thing happened to me last week (plug gap was off)

 

Pulled spark plug wires individually, Each changed tone of the engine the same. Ngk colder plugs gaped at .26. I will try to pull injector clips tomorrow.

Thanks for your time.
DK

 

i'm gonna go with burnt valve or something along that line..

 

yeah if all 4 plugs changed the idle the same like you stated it very well may be something in the head like stated above...wont really help much to pull the injectors if they were all the same since you basicly know its firing in all 4. I would start doing a compression/leakdown test

 

I bet it's going to be a significant loss of compression on one cylinder with the possibility of slight loss on a second. Damaged piston.

 

mine sounded like a Subie once...check the plug wires. Thats what happened to me...props to Nick from SLS for making me check the easy stuff first

 

if you pulled the plugs on each cylinder and they all changed the idle then its not gonna be any thing wrong with the injectors either. next thing I would do is check the compression if its low on any cylinders add a teaspoon of oil then test it again. if the psi raises then that means either your compression ring is bent/cracked or your ring land is cracked...but after adding the oil the psi doesnt change then thats pointing towards the valves, you can check that with a leak down test. the results from the leakdown test will tell you if your valves are bent or chipped or headgasket...probaly wouldnt hurt to check the spring tension and height.

 

yeah....it's likely something melted...do a leakdown, that'll tell you for sure.

 

I'm on the way to my shop, It just seems like if something was bad wrong it would be smoking at least..

 

No not necessarily at all. If it's just a small edge of a piston melted, or a burnt valve it won't smoke at all. You can tell by driving it, because it ildes terrible but as the rpms get higher it'll smooth out a little, or in some cases almost entirely.

 

Probably a cracked ringland

 

I've had pistons with the ring lands cracked in three seperate peices drive fine with no smoke...eventualy it will begin to smoke when the weather gets colder it will start to smoke bad. like they said above, it will idle like crap but when you get up in the rpms it will smooth almost completely out, it'll probaly skip alittle just like it would if the spark plug gap was to big. do a leakdown then post some pics after the teardown.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by IN VTEC &raquo;</TD></TR><TR><TD CLASS="quote">I bet it's going to be a significant loss of compression on one cylinder with the possibility of slight loss on a second. Damaged piston.</TD></TR></TABLE>

thats what im thinking.

 

The same thing happend to my friend with a RSX S, when he put the greddy kit on it and did a 3rd gear pull and when we stopped it sounded like a V8, Burnt pistons!

 

Did an compression test,
162-160-90-167

This really sucks..

I went and bought a civic hatch today.. haha

I wonder if it was the tune that jacked it up..

It does smooth out after 3.5k rpms..

 

I just wonder if time did this or was it a shitty tune..

I only had it boosted for 2k miles.

 

how many miles on the block and how much boost? depending it was most likely running too hot but if it were in rough shape to begin with it may have accelerated any problems it had

 

unfortunately i know this one all to well. DETONATION

 

damn...that sucks. when you tear down post up a pick...probaly cracked a cracked ringland.

 

post your bin file or screen shots of your tuning

 

You say your were messing with the boost; did you happen to run more boost than you were tuned up to?

 

130k miles on engine when boosted.. I remember my tuner disabling my knock sensor ;( This engine was mint, when I pulled the oil pan it had no discoloration what so ever. I have all the maintenance records sense new.

I had it up to 10psi for 2 pulls and then removed the boost controller. My afrs were 11.5-12 on 8psi, and I turned it down because it was up to 12.5afr when I turned it up to 10.

I honestly blame my tuner. My engine bay put off so much heat, I said the timing needed to be more retarded but he said it was ok, he said something about 16 degrees of total timing I think.

Sorry I don't have any bin files.

I just need to know if I was at fault or my tuner. I need to know if I should take it to him when I get it fixed.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Boosted_B_Series &raquo;</TD></TR><TR><TD CLASS="quote">130k miles on engine when boosted.. I remember my tuner disabling my knock sensor ;( This engine was mint, when I pulled the oil pan it had no discoloration what so ever. I have all the maintenance records sense new.
</TD></TR></TABLE>
When you start modding your car the stock knock sensor becomes very innacurate. Plus were you using a p72 ecu or anything else that had a knock board in it? If you use the standard p28 like most people they dont even support knock sensors.

 

I have a loaner b16 chipped ecu while my b18c ecu is being chipped...