Help reading inconsistent plugs on freshly rebuilt engine. Running rough.
 

Hello All,
My father and I just finished rebuilding our 1982 Euro 930 engine. Full rebuild to stock with ARP hardware due to 3 broken head studs. We tore down and shipped the engine parts to Ollie's for machining, valve job, rebuilt bushing, ect. Fuel head was removed and reinstalled. I did clean the injectors out with brake cleaner and replaced the fuel filters before reassembling but other than that, I just removed and reinstalled the fuel system.

After priming oil and fuel, we started the engine and it sounded like it was running really rough. Pulled the intake and when I pushed down on the CIS flapper, it sounded more rough. I assumed it was running rich.

Drove around town to seat the rings and as the car would get warm, a small backfire would emerge at idle from exhaust. I was preparing to check WUR with gauges but on the way home, it sputtered down and wouldn't start. Towed it home the next morning.

Compression 132 - 137 on all 6, timing set to 1 degree advanced at idle, Spark on all plug wires at each cylinder and fuel dripping from line coming to injector on number 5.

I pulled the plugs and to my surprise. Cylinder 3 looks clean as a whistle while the others appear to have fouled out. I'm thinking clogged fuel line or injector to number 3.

I also visually scoped each cylinder and the pistons look the same as each corresponding plug.

What would you guys recommend? Am I wasting my time checking WUR fuel pressures and then putting all the injectors in glass containers to measure for consistency?

Thank you all for the help!
Doug

http://forums.pelicanparts.com/uploa...1478991566.jpg

Yes, 3 is running leaner as is 2, but the rest are really rich. 2 and 3 must be clogged and then a pressure check is due on the CIS to get the AFR's correct.

Thank you for the tip Tippy. I'll test the WUR pressures and blow air through the supply lines tomorrow, as well as removing the injectors on 2 and 3 and confirming a clear spray pattern. Hopefully clogs are present and no need to adjust WUR, or whatever all that entails.

Are these plugs toast or can they be cleaned up?

Seems like you're on the right track. How long has it sat? I'd check for flow at the #2 injector first. Then swap it out with one thats flowing. At that point you'll know the problem is either the injector or a clog behind it. You can buy rebuild kits for the feul heads pretty cheap online or send out the fuel head, lines and injectors to Larry at Flowtech. He's honest and reasonable.

After reassembly of the fuel head and lines, air in the lines can be present and take some time to remove. I would detach the lines from the injectors and press the flapper down to see how each line flows. Please note, that the connection where the conical ends of the steel lines meet the female receptacles at the fuel distributor/head is very sensitive to alignment and tightness. To get the correct flow you may have to play with said alignment and tightness, and many times, if you over tighten that connection, the line will not flow, correctly. You can play with the tightness with the engine running and you will be able to hear changes in the idle speed.

As well, prior to reconnecting the lines to the injectors I would turn the engine over with the spark plugs still out to remove any fuel left in the cylinders. Purchase new spark plugs and put those in. Do not use the set you have shown us. New ones could make a world of difference. Just ask me how I know...lol

Even though you have cleaned the injectors, some still may not be working, correctly. Once you have taken the above steps and it still isn't running well, remove one spark plug wire at a time to see the removal's affect on the idle. If you pull a wire and do not notice a drop in idle speed, that cylinder is not working right and you may have to still play with that line's connection or need to remove the injector to see how it is flowing.

I used to wire wheel my dirty plugs on carb'd engines and they'd be fine. It was the gas fouled ones (really wet wuth fuel) that never seemed to come back to life.

It sat for almost 2 years during the rebuild and only after did I read that the fuel head should be laid flat for storage. I was sitting on the shelf mostly flat but a little tilt. Thank you for the reference. We are probably giving it a paint job over the winter so I might send the fuel items out then to complete the overhaul. Really want to spend some time driving it with my father so trying to get it back as is would be great. We felt we were so meticulous on the rebuild, we were a bit devastated when it didn't run right. The various oil leaks on flare fittings didn't help much with morale.

This is very interesting! I'm hoping I just over tightened #2 and #3 connectors. I was thinking I was returning to a similar spec as they were quite tight on removal. Would a 1/4 turn past no leaking be reasonable?

I guess the plugs have been voted to the trash can. Except for plugs 2 and 3.

I was just hoping to reuse the plugs while diagnosing the rich condition so I don't ruin another set of plugs. I saved the old parts just in case, so I will probably use the plugs that came out. They only had a couple thousand Kilometers on them.

You can adjust the tightness when the engine is running to hear the affect of the tightening.

Also, I just thought of this, but remove the line connection fittings at the top of the fuel distributor and press down on the flapper to see how the fuel is coming out of the head. You will notice any flow problems from the head much easier, that way, if you have any. Also, make sure that when you allow all that gas to flow over the engine in the little experiments I suggested, you allow the gas to completely dry prior to starting your engine!!!

Replace your old spark plugs with new ones, only. You can always use the extras later on. It is not worth saving a few bucks only to wonder if your problem is still a fouled plug...

I pulled #2 and #3 injectors and they were indeed clogged. I was able to get the injectors to flow again by flushing them both directions with carb cleaner and air. I pulled #5 injector to compare with. I put injectors 2,3 and 5 into cups and then pushed the metering flap to activate the pumps. All three cups had the same amount of fuel after 30 seconds.

I tested fuel system pressure to 5.8 bar and cold control to 1.8 bar. While I had the plugs out, I cranked the starter with the distributor pulled to clear the fuel out of the cylinders. After letting the gas evaporate, I put the pre-rebuild plugs in to see if I could get it to start to then check the warm control.

If I pressed the gas pedal down to the floor, after a lot of cranking, I got it started. It ran really rough and needed some gas pedal to stay idling. It set into an idle after about 20 seconds of nursing it. I went back and pulled plug wire 6, no change in idle. I then pulled plug wire 5 and it started to idle smooth but like it was only firing on 2 cylinders as idle was really low and quiet. I cut the engine.

I put a clean spark plug in cylinder 6 but no start. I confirmed visually that both spark plugs were sparking. I then heard gas dripping from a exhaust connector flange. So I also found an exhaust leak but I wouldn't think that would contribute to the rough running/no start. Seems like a lot of gas to be running out of the exhaust after 5-6 30 second cranking session.

WUR xxx.xxx.054 cold pressure spec is 1.6 bar at 10 celsius and I had 1.8 bar at 15 celsius for cold control pressure with the WUR unplugged. Which I would think sounds close enough to start. Cold the cold start be dumping fuel and causing the very rich condition?

I ordered new spark plugs, but I will see if I can buy some local tomorrow. I am seeing spark so the plugs are not fouled completely but maybe new plugs and some time for the flooded engine to dry out will help. Plugs look so black that I have to be really rich.

Thanks for any suggestions guys.
-Doug

Doug

Take heart, you are getting there, and believe it or not, you are almost there! When I first started my engine the last time I put it back together, it took quite some time before it ran, properly, and It was doing exactly what your's is.

Remember, every time you push down on the flapper when the fuel lines are connected to installed injectors and the ignition is on, fuel is going to each and every cylinder. Gas leaking out of the exhaust is telling you that you have unburnt fuel in the cylinders. So tomorrow, make sure you turn the engine over for a bit before you reinstall the new plugs (you may have already fouled the ones you put in since there is unburnt fuel in the cylinders). As a precaution, do not turn the engine over until all the plugs are out.

Once it is started, keep it going. It should begin to run fairly well in a little bit, if everything is checking out good. I'll assume you do not have any vacuum leaks and that your intercooler connections are tight, too.

Good luck,

Geoff

Nice work sorting your injectors. I agree with Iceman, get it started and keep it started. As for the plugs, take Tippy's advice. A little gas and carbon can easily be cleaned off with a wire wheel.

New spark plugs are easily cleaned if fowled.
How did you store the fuel distributor and WUR? Was gasoline left in them?
Was the fuel filter changed before firing up the new engine? Gas tank drained and new fuel added?
Old injectors are junk. You can clean them but the result is clean junk. Ideally the FD and WUR should be rebuilt and new injectors installed on fresh engines. You may need to clean multiple times as contaminants work their way through the system. Be sure to check the WUR inlet screen as well.

air leaks
bad injectors
bad fuel head

check you manifold bolts. you could have air leaks,
also the way you out the intake gaskets on makes a difference. both sides do NOT go on the same direction. if you put them on wrong the gasket has a VERY narrow edge that seals,
did you use old plastic injector blocks.
was the surface of the intake flat
bad injectors.
I thought my injectors were good even after cleaning them. had them tested when I had my FD rebuilt. one of them blew the pintle out. questioned another one and sent it back and it blew the pintle out. ended up just replacing all 6. best thing I did.
over tightening them will not make the not work.
check for fuel leaks at the fuel lines, FD and injectors.

bad fuel head
the euro fuel head can dimple the shim in there and cause problems. could also have some corrosion in it. rebuild it. its not that much and its worth it. flowtech (flowcontrol). cant ever remember which it is.

at first it looked like it was just the right side rich and thought maybe the cam timing but you could really put #1 in there with the other 3. this would also should up as different compression on the right vs the left.

don't dump all that fuel into the engine testing the injectors. BUT, if you can, pull all 6 injectors and test all together,. its a pain.

PLEASE, if there is raw fuel splashing around back there, spilled, or getting pushed out of spark plug holes etc, make sure you have disconnected your ignition, pulled your rotor, or otherwise make sure there will be no spark.

How do I know? I once started an engine fire in an SC right after a rebuild doing EXACTLY this because a spark set off the spilled fuel.

That dry chemical fire extinguisher makes a HELL of a mess, is corrosive to AL, and practically impossible to get rid of. I was still finding it 15 years later when I sold the car.

reminds me of my 280z.
rained for several days straight. ran out of PAVED road at night at 65mph. slid through the mud for quite a while.
years later I was STILL pulling red clay out of nooks and crannies on that car.

I agree with the other guys regarding the injectors. Unless you are able to get it running well, soon, you may want to buy some new ones. I cleaned the heck out of mine and got my engine going fairly well, but finally just broke down and bought a new set. It ran better after that. If you decide to buy a new set, you can buy the US version or the European version. The Euro's will spray more fuel (I can't recall how much more, at this moment, but more fuel means more HP), but they cost quite a bit more, too...

Thank you for the encouragement. Much appreciated right now!!!

I pulled the plugs today and cranked with fuel relays and capacitor wire pulled. More gas leaked out of the exhaust. Not even going to bother until it dries out.

I have some new plugs but I might have plugs for life if they do clean up.

I would imagine the FD and WUR had residual gas inside as I just removed and placed carefully on the shelf for the 2 years. New fuel filters, pumped the tank dry, fresh gas in and then used the pumps to run a quart or so of gas through the supply line into a jar. It looked and smelled like the new gas. It has since run 1/4 tank of gas with all the driving and testing. We filled the tank up to 3/4 full with new gas while it was running before the sputter out/no start issue presented itself.

I was planning on having the FD, WUR and Injectors serviced this winter as I was thinking it would be less to troubleshoot the the rebuild if I didn't touch the fuel components. The car was running very well until the head studs let go. Now I am regretting not doing it during the rebuild.

Intake gaskets not the same on the 2 banks?:eek:

I thought a vacuum leak would have been ruled out as the plugs are rich and I thought a vacuum leak would present itself as lean until boost hits. I also sprayed flammable carb cleaner at the all the hose and intercooler connections with no change in idle. When it did idle that is. I did not target the original plastic intake blocks. So that is a direction to look when I can get to idle status.

I was thinking maybe timing with 1,2,3 being way less rich than 4,5,6. But when I found the clogged injectors on 2 and 3 I thought it had to be fuel related. I probably tested the cam timing ten times during the rebuild. Took a video of the test to put myself at ease in this very situation. Cams good! I even pulled the valve covers and rechecked while the engine was in the car. That was before it fired up the first time. Pretty much identical values for 1 and 4 timing and right in the middle of the tolerances. The compression was incredibly similar at 132 to 137 or so on all cylinders. I didn't bother charting each cylinder with the numbers so similar.

Thank you for sharing your extinguisher experience. That was certainly the plan but I'll use the hose on mist if necessary. That would be a bad day for me and my garage. Not sure how I would get the wife back on board with putting up with a garage reeking of gas after that. I did ask her if she wanted to play fire fighter and posted her with the hose on the initial starts. Not sure if I should have planted that seed?

It is a euro 930 so I think I'll stick them.


So here is where I am at now. I pulled the plugs this morning and 4,5,6 were still visually wet after 30 hours of sitting. Plug 3 somewhat wet, plug 2 was bone dry and plug 1 was maybe moist.

I think it is best to pull the FD, WUR and send out to be serviced. I hear new injectors are the way to go. If anyone thinks it is work throwing these new plugs in to give it one more go, I would prefer to try that first. But the smarter part of my brain is saying stop and do it right.

Do I have a second on the motion to give it one more try with fresh plugs?

Should I pull the Cold Start as well for service when sending FD and WUR?

Thank you all for the help. Feels like a team sport http://forums.pelicanparts.com/suppo...s/beerchug.gif

As I think you have been doing, with the fuel pumps disabled, go ahead and turn over the engine for 15 seconds to get rid of the gas in the cylinders with all of the spark plugs removed. Clean off any gas that landed on top of the engine. Dry the new(er) plugs and reinstall. It should run, now, after a bit of coughing! Don't forget to enable the fuel pumps before attempting a restart.

If it doesn't run well after a lengthy try, and you think it might be the fuel head, before you send it out for repair, try the one thing I told you about, previously. Remove the line fittings at the top of the head so the head ports are visible. Reconnect the fuel pump and push down on the flapper to see if all of the ports are flowing, equally. If they are, you most likely don't have a problem. If they aren't, try getting some Berryman's carb. cleaner and shoot some in the ports. Let it sit a bit. See if the flow improves. Try it a couple of more times. If it doesn't improve, you can always take the head off and inspect and use the carb cleaner for any dried fuel residue that are gumming up the ports' bits. Clean the individual port bits and pieces with the cleaner. Look at the diaphragm's condition. If it looks good, reassemble. Try to restart the engine.

Cranked it clean, new plugs in, fuel on and it barely got started. I know I could have kept it running, but it sounded so bad I wanted to check before putting the engine through much more of this slamming sound. In the video I almost got it running again.


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I then heard gas dripping from the exhaust header collector after making the video. Seems like a lot of fuel is getting dumped in if after cranking to a start for 20 seconds, the engine running for about 1-2 minutes and then another 30 seconds of cranking for the video and now there is gas dripping from the exhaust collector.

I guess I should pull the fuel head and clean it up? It appears the fuel is consistently coming out of the FD. The picture shows how even the amounts were and there was even a little spilling which I think explains the cup with the least.

http://forums.pelicanparts.com/uploa...1479268625.jpg