Arrrgh.... bad fuel injector now, too?

[ret]

Any quick tests for the fuel injectors? I'm going to try the cylinder balance test after work today, but shotimes.com says that isn't guaranteed to show injector issues. I hadn't noticed this before as my stereo is always up nice and loud (if you can't hear the problems, they don't exist, right? j/k), but while trying to take care of this God forsaken EGR valve, I noticed a steady knocking sound coming from my engine. About 1 knock every half second to 1 second or so (at idle, which is a bit low.. ~800 RPM, thought my EGR issue was causing that, but perhaps it's an screwed injector). It isn't very loud, even listening for it from within the car I couldn't really hear it, although the car does have a slightly rough idle, vibration timing about right with the knock (never noticed that thanks to the subs shaking the car anyway). I took the car and had it hooked up to an injector cleaning machine to see if that would fix it, still has the problem. Sound like it's time to replace the injectors? If so, where would be the cheapest place to get them? Is it difficult to do (read: should someone who'se IQ drops about 50 points and motor skills are reduced to that of an epileptic during a seizure as soon as they take a wrench to an engine attempt to change them)?

 

[luigisho]

I wouldn't be so quick to assume injector failure. That being said, I bought used & flow tesred injecters from sho shop because you get all 6 for the price of 1 new. They are fairly easy to install. You may notice you need new seals when you pull them out which may get expensive if you can't find someone w/a spare set.

 

[ret]

Well, glad to hear it might not be the injectors... any idea what else it might be? It's not as loud or "clicky" sounding as sticky lifters I've heard in the past, so I'm assuming it's not that, but I've gotta change my oil this week anyway, so I'll run some engine flush through and see if that clears it up.

<small>[ April 06, 2002, 11:58 AM: Message edited by: ret ]</small>

 

[sdpatt]

Have you ruled out a valve tap? How long since your last valve gap adjustment. This is much more likely to cause 1 tick for every two engine revolutions than an injector. Try putting a wooden dowel or metal rod to the valve cover and placing your ear on the other end. can you hear it more clearly? The front valve cover has another option - just take off the oil fill cap. It is very obvious if one of the 4-5-6 cylinder valves is making the noise with the cap off.

 

[ret]

I had the engine rebuilt with a new long block about a year ago (almost exactly, actually), so about 1 year or 20k miles since the last adjustment. Is this the same as the every 60k-100k valve lash adjustment?

 

[sdpatt]

Yes. Does the long block include the heads? If so, I guess the question remains as to how well the gaps were set when the heads were added to the engine.

Scott

<small>[ April 07, 2002, 04:31 PM: Message edited by: sdpatt ]</small>

 

[ret]

No, the long block didn't include the heads, so it has my old heads with 140k miles on them. I wish I could remember if it had been knocking when I first got it back... I was so excited just to have my SHO running again after about 4 months out of commission that I didn't pay any attention though.

 

[luigisho]

How many miles on the heads? I think with all these cars getting on in age the heads may require alot more vigilance. Which means people like me need to get the valve lash checked and keep an eye out for worn valves and valve guide seals.

 

[ret]

Ah, I found the cause of the knocking. I don't know why this didn't show up in the KOER tests before, but today it did both times... error 225 - knock sensor is borked (that's exactly what the manual says, I swear). No mention of the knock sensor in this chilton's manual so far... I checked both emissions controls, fuel system, and the index in the back of the book. I gotta run soon, but I'm gonna do a quick search on the net to see how hard this is to change... looks like it's only $30 at carparts.com if I can figure out how to change it.

Heads have 137k on them. I assumed that the valve lashing and whatnot would have been handles as part of rebuilding the engine... was I wrong?

On the plus side, my cylinder balance test gave me a 9, so at least something is working on my car.

<small>[ April 06, 2002, 04:16 PM: Message edited by: ret ]</small>

 

[luigisho]

I doubt your rebuild included tearing into the heads. I can't be sure of course but I believe that head work is seperate from rebuild of the motor. As for the knock sensor, if that's the problem then that's good news. Not too difficult to replace. It's under the intake, I forget if you have to move the fuel rails also.

 

[sdpatt]

Yes, the fuel rails have to come up too. It would be a good idea to get the six injector gaskets (square section O-rings) that seal the injectors to the heads and replace them when the injectors come out with the fuel rails.

Scott

 

[luigisho]

Scott, have you found a reliable source of these gaskets or are they only offered in the expensive upper gasket sets?

 

[sdpatt]

I have a spare set of the gaskets that I had purchased from Forum members. I can forward them to you for what it cost me to acquire them. Please get my personal email from my profile and contact me through the mail or send me a private Forum message.

Scott

 

[ret]

Well, my knock sensor error is gone... I don't know what the deal was with that. I'll check test everyday after I drive home from work and see if it stays gone or not. Thanks a lot for the offer for the gaskets and such though, if the error comes back I'll have to take you up on that.

My EGR though, is driving me nuts. I pulled the throttle body off today, but I didn't see the nostrils (or I looked right at them and just didn't know what I was looking at). I pulled the EGR vacuum sensor and cleaned the tubes for that as one of them was crudded up, but no luck there, still giving me the egr error and check engine light is coming on. Are there any diagrams that show the nostrils and such anywhere? I looked at the diagram of the egr system in my shop manual and I didn't see anything that made sense to be them... just egr valve, the tube running from the egr valve down to the exhaust manifold (I assume this is not what you were talking about as I saw no way to get to the end at the exhaust manifold from up above the engine), and the two tubes running from the egr valve over to the egr vacuum sensor, which I inspected and cleaned. I didn't go all the way and pull the intake manifold off to see if I could see it at that point since I didn't have time today (first time ever doing any car work beyond spark plug change/oil change/etc) so it took me a little longer than average... will do that soon though if I don't get it fixed, the throttle body should only take me 5-10 minutes to take off next time. btw, if anyone is going to be doing this work on their car soon and has a digital camera or a regular camera and scanner available, maybe you could take a couple minutes to take a picture of what I am looking for.

Just doublechecked my longblock (ordered from SHOshop) and it did come with rebuilt heads, so these are not the 140k heads anymore.

anyone know of any mechanics in the richmond, va/petersburg, va area that know their way around the SHO engine if I can't figure this out?

thanks again for all the help you guys are providing, I really appreciate it.

<small>[ April 07, 2002, 07:16 PM: Message edited by: ret ]</small>

 

[bigblksoul]

The rubber seal on one of my injectors is cracked, and the o-ring must have been pinched during installing because it's missing a chunk out of it. Does anyone know where to get replacement o-rings and seals from? I've looked all over with no luck. I ordered what I thought was a replacement o-ring kit from RockAuto.com but the o-rings where way too big. I sure would hate to buy a new injector!

 

[ret]

Ok, I just re-read the shotimes.com writeup about the egr valve issue. I can probably figure it out now, although any diagrams that are out there still would be helpful.

 

[luigisho]

I think you can get the o-rings from autozone. You just have to get the correct part#. The seals only come from the complete upper gasket set (not the usual felpro cam cover/plug well seal set). If you can find someone who got the complete set and didn't use the seals maybe they will sell them to you.

ret-maybe you should repost to get responses for egr asst.

 

[ret]

Yeah, I might do that, luigisho. I'm going to take another look this evening now that I'm more familiar with what I'm looking at and looking for and see what I find. I'll repost to try and get diagrams or pics if I am still clueless.

<small>[ April 08, 2002, 09:36 AM: Message edited by: ret ]</small>