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Discussion Starter · #1 ·
Hello everyone. I've been working (slowly) on my 1981 GTV6 which I got a few months ago (you can read my first post about it here: http://www.alfabb.com/bb/forums/alfetta-gtv6-1972-1986/263561-fuel-air-intake-flames.html).

Since then I did the following:

- Had injectors and cold start injector rebuilt by OK Injectors
- Had gas tank cleaned professionally
- Installed new fuel pump
- Installed new fuel filter
- Installed new fuel hoses
- Installed new fuel injector to fuel rail hoses
- Cleaned fuel rail
- Installed new intake runner hoses
- Installed new valve cover gaskets
- Installed new spark plug seals
- Installed new spark plugs (NGK BPR6ES - verified correct gap)
- Installed new timing belt (verified correct timing with cams, ignition rotor position and TDC of cylinder #1)
- Correctly gapped exhaust valves
- Rebuilt hydraulic timing belt tensioner
- Installed new v-belt
- Installed new water pump
- Rebuilt thermostat housing
- Installed new thermostat hoses
- Installed new ignition rotor
- Installed new distributor cap
- Cleaned all electrical grounds
- Installed new high cranking Interstate battery

After all this I was able to get the car running, albeit with some difficulty. You can see a short video of the engine running here (the smoke coming up are just fumes from the cleaning substances):


Now even with everything that was done above, it was still not easy to get it running. The cylinders would still fill up with gas (and some fuel would leak out the air intake). I had to remove and clean the spark plugs a number of times before I was finally able to get the engine running.

I tried running the car the day after the above video, but was having the same problem - difficulty in getting the engine running, fuel out the air box, wet spark plugs.

I also noticed another problem: cylinder 2 and 4 are not firing. I verified this by removing the spark plug cable from each cylinder, one at a time, and observed the behavior of the engine. The behavior changed with all the cylinder except for 2 and 4. You can see the video of this procedure here (also you can here a clicking sound which I believe is the air box flap slapping as it opens and closes, which I talk about a little bit below):


I then removed all the spark plugs and saw that the spark plugs for cylinders 2 and 4 are like new. I also noticed that they are not even wet.

Finally, when I was trying to get the engine running again yesterday, as soon as it was about to start, it would backfire (I heard the air intake flap open and close) and stop. I did not insist in trying to get it started.

So these are the symptoms: cylinder 2 and 4 (one on each bank) are not firing, wet spark plugs (except for 2 and 4), backfiring and fuel being pushed up the intake.

I verified that there is spark to each spark plug. I verified that the timing is correct. The injectors and cold start injector have been professionally rebuilt and verified to be working correctly by OK Injectors. The fuel system is clean. All electrical grounds have been cleaned. At this point I do not know what else to do. I am thinking, maybe, there is an electrical issue with the harness going to the injectors, but how do I verify this? Should I try to get the engine running again and some how check the wiring harness? I have no idea.

I would truly appreciate any help possible. Thank you.

Igor
 

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Discussion Starter · #3 · (Edited)
Hello Eric,

Thanks for your quick reply. The spark plug wires are numbered, so I connected each to it's corresponding cylinder number. I am fairly sure they are correctly connected.

PS I just verified and all cables are correctly connected.
 

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Discussion Starter · #4 ·
Here's a little update to the situation which might help diagnose the problem.

A friend suggested to a compression test to see if there was compression in the two non-firing cylinders. I did the compression test and here are the results:

Cylinder #1 150 PSI
Cylinder #2 160 PSI
Cylinder #3 135 PSI
Cylinder #4 135 PSI
Cylinder #5 140 PSI
Cylinder #6 150 PSI

There is a little discrepancy between them, however it seems to me to be a decent reading.

With the coil cable disconnected I then connected a light tester to the Bosch connecter which gives power to injector #4. I cranked the engine and the tester light would turn on intermittently - I assume, then, that the injector is receiving power.

I reconnected everything and tried starting the engine once more. Again with difficulty it was about to run, but then I heard a loud "spurt" and little puff of white smoke rose from the driver side exhaust. The engine quit as soon as the "spurt" occurred. I did not continue to crank the engine.

Lastly, as I was removing each spark plug to test it's compression, I did find that the spark plugs for cylinders 2 and 4 were wet, however they were black. I smelled the fluid deposited on the spark plug and it did not seem like fuel to me... maybe oil.

Again, all suggestions are appreciated.

Thanks.
Igor
 

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Discussion Starter · #6 ·
Hi Eric,

I did indeed check that as well and they are correctly connected to the distributor.
Thanks again for your suggestion.

Igor
 

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Just a thought, have you verified that your fuel pressure is within spec?
 

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Since the injectors are batch fired (all at the same time - not sequentially) you can try swapping the electrical connectors and see if the 'dead' cylinders remain the same or move with the relocated connectors.

If they stay the same (and you are sure the spark plugs wires are connected correctly) then the injectors may be faulty.

If they move with the connectors then there is a wiring fault in the FI circuit.

And before doing any of that, have you tried cleaning &/or swappng spark plugs or putting in new ones into #2 & #4? All the failed starting attempts could have fouled the spark plugs so badly they will not ignite the mixture.
 

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Discussion Starter · #9 ·
Hi bill2000. I did not check the fuel pressure. I will try to do that sometime this week. Thanks for the suggestion.

Eric, thanks for all your suggestions. I did replace the spark plugs with new ones and have the same issue. I did not, however, swap the electrical connectors. That's a good idea and will give it a try some time this week as well.

I will also be replacing the coil and all the Bosch EV1 connectors with new ones soon (probably next Sunday) as they are a bit worn and some of the connectors have the plastic ends chipped.

Igor
 

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Just a couple of suggestions:

Double check the cam and distributor timing. Compression looks reasonable, especially for a car that hasn't run in a while.

Put the old rotor and cap back on. I've had bad new parts before and that is a pain to diagnose - you assume that they aren't the issue.

Check all the vacuum hoses (especially the main intake boot) carefully for cracks or leaks.

It doesn't sound right that you have so much fuel at the engine that it is running out the AFM. You may need to pull the injectors and verify that they shut off. Fuel pressure validation would be good too.

I remember starting the first engine I ever rebuilt. Took me a week of flames out the carburetor before the old guy down the street poked his head under the hood and said "You have the distributor wired backwards". Wired it to rotate in the other direction and the engine fired right off and ran fine.

You'll find the solution!
 

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Wow, those clips sound terrible. I would have thought it was timing and/or that the spark plug leads are connected in the wrong order or bad. But you say you have confirmed that there is spark at each plug, that the timing is correct, that the leads are connected correctly to the distributor and that the distributor is timed correctly.

I think gnhl's advice to move injector leads around is a good idea as that'll confirm if the injector wiring is ok.

I'd also disconnect the cold start injector lead as you seem to always have too much fuel and see if this helps with the fuel coming out the air intake. Have you checked your Thermo Time Switch?

Maybe you have more than one problem. Have you gone through L-jetronic Fuel Injection Technical Troubleshooting Article and tested everything step by step?
 

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Discussion Starter · #12 ·
Thank you all for your suggestions and comments. Some time later this week I will try swapping the injector leads and see what happens.

I will also check fuel pressure and the Thermo Time Switch, which I haven't yet.

TPAlfa - I did indeed go through, although not entirely yet, the various procedures detailed in L-jetronic Fuel Injection Technical Troubleshooting Article. This weekend I will follow steps 4 (The cold start and warm up system) and 5 (Fuel Pump and Fuel Pressure Regulator).

I do have a question regarding timing; I am 100% sure the timing is correct (I checked and rechecked this), however I am not 100% sure the distributor is timed correctly. However, if I cannot get the engine running, how can I get the distributor timing in the right ball-park? Should I try to get the engine running, even if it backfires? Would I be possibly damaging the engine if I did?

Thanks again for all your help.
Igor
 

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Igor,

Set the engine to TDC on the crank pulley - and make sure that the cams are at their timing marks - you can just pop off the round plastic covers and use the timing marks on the timing belt cover for this. (You want to make sure that you are on the fire position, not 180° off. Remember cams rotate half as fast as the crank)

Now note where the #1 plug wire is on the distributor cap. Pop the cap off and the rotor should be pointed at the #1 plug wire position. There is a small timing mark on the outer edge of the sdistributor too (at least on mine). Loosen the distributor clamp and rotate the body unil the rotor points to the right position. If the rotor points at the timing mark or #1 plug wire position, it is good enough to get it running.

If you are way off and can't rotate the distributor to the right position, then there are two possible options;
1. Remove the timing belt and line everything (crank, cams and dist drive) up for TDC
2. Pull the distributor and rotate it to correct position - remember that there is an oil pump drive that engages the lower end of the distributor shaft. This will likely need to be repositioned using a screwdriver to allow the distributor to drop back down.

Neither of these is the most fun job, but if the T-belt is new and correctly installed I'd opt for number 2.

A timing light will dial it in to exact.

I'd recheck all timing, wiring and hoses before trying a restart. Also the recommendation to pull the plug from the cold start injector sounds good if you have fuel running down to the AFM.

You'll get it with persistance. Think of the feeling of victory when you do.
 

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Also do not try to start the engine with the throttle partly open, Your foot must be OFF the gas pedal, otherwise it will back fire. You can disconnect the cold start injector if you are getting flooding, as that injector puts a lot of fuel into the air box.
 

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Sorry should have been a bit clearer when I said distributor timing. As per Mark toro's instructions and ghnl's diagram, I meant that the timing should be within a few degrees of correct - and yep, the final timing requires the engine to be running. But, it is running so bad it just seems like a timing problem. One other thing - you say the car was sitting for 13 years, it may pay to unplug all the electrical connectors and spray them with contact cleaner - especially the big one on the ECU. Hope you can sort it out.
 

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I suggest starting from scratch.

Position the engine with #1 at TDC on compression. Only turn the engine in the 'forwards' direction - with a socket on the crank pulley nut turn it as if you were tightening it. Check that both camshafts are on their marks (if the engine was turned backwards it will allow the timing belt to slip).

Remove the distributor cap and note where the rotor is aimed - a photo looking straight down at the distributor with the cap off will help us know it is positioned correctly. (when the timing belt was removed for replacement the distributor drive cog can be inadvertently moved out of position)

Trace the #1 spark plug wire from the spark plug to the distributor cap. Make sure it is plugged in to the terminal where the rotor was aimed. Follow each spark plug wire and make sure they are connected in the correct firing order.

Make sure all the short hoses between the intake plenum & the individual intake runners are secure. Make sure the large air duct is securely attached to the Air Flow Meter & the throttle body. (a backfire can dislodge them)
 

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Sounds like a fuel injector wiring connection problem. Check that the lead/s inside the AMP connectors of 2 & 4 fully engage the injector. It happened to me with one lead on #3 and it nearly drove me nuts. Push the wires into the connector/s and see if that helps.
 

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Discussion Starter · #19 · (Edited)
Hello Everyone,

Thank you all for the great advice. I will try to follow all your suggestions this weekend and hopefully discover the culprit.

Regarding the timing, just to be sure I did it correctly, following are some pictures I took as I was removing (and later installed) the new timing belt. I am positive I followed the procedure correctly...but it would be nice to get confirmation from more experienced and knowledgeable owners here.

Cam timing mark on driver's side:
Metal Brass Auto part

Cam timing mark on passenger's side:
Auto part Metal Gear Automotive engine part Hardware accessory

Crank timing mark:
Auto part Automotive wheel system Wheel

Distributor/ignition rotor timing mark (this is very slightly off here, but was spot on when I installed the new timing belt):
Auto part

Front of the two camshafts showing direction of front marks:
Auto part Engine Automotive engine part Metal Transmission part

Before attempting to change the timing belt, since I know it is so critical to do it right, I read and reread the procedure numerous times to be absolutely sure I was doing it correctly. Please (hopefully) confirm that indeed that is the case.

Thank you all again.
Igor
 

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Your cam alignment marks appear to me as good as it gets for stock (non adjustable) cam pulley sprockets. Everything else looks properly aligned also. If you can, do paint your crank pulley marks; makes ignition timing a bit easier.
 
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