So I sent my injectors to the reputable injector guru and got them back within 2 weeks then installed. The car ran very well before the cleaning but ran happier with the serviced injectors

But after about 40 or so miles, #3 cylinder stopped firing The plug in the #3 cylinder got sooty and there was unburnt gas in the right bank of the HE. Other 3 plugs look good. I wonder if the recently serviced injector has failed or something else has gone bad

The car runs OK only about 5 min. if the plug is cleaned, then starts to reduce power with gas smell and frequent popping along with acceleration. I also noticed the motor does not want to rev up high when this happens.

What could be the reasons to misfire beside a failed injector? Please list.

Thanks in advance




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The solenoid is not closing (injector stuck open) and the fuel pressure is pouring gas into the cylinder drowning out the spark with liquid.

The return spring could have broken.

Replace the injector .......

Possibility of a bad high tension lead (spark plug wire) not firing the plug also.

Possiblity of bad Beru connector ... cracked ... spark going to ground.

Possiblitity of a bad spark plug ... juice going to ground ... cracked center electrode insulator, etc ..........

Possibility of a cracked distributor cap or dirty inside causing arc to travel to ground rather that cap electrode .......

This sounds exactly like what I'm going thru. Even the injector servicing. However, I swaped injectors between 3 & 4 but I still have a very weak #3. Compression is 135 wet on 3. I'll be watching this thread.

Oil fouling #3 ? FI would continue pumping fuel through it.

In my case, I don't think it is oil. How bout you, kkid? Mine leaks out too quickly to burn

My #3 is not oiled at all but sooty on the plug and gasoline in the exhaust.

I swapped #3 and #4 injectors but did not get a chance to run since it is rainy outside.

Brad suggested I switch 3 & 4 injector leads , also. Just in case they had been flip floped. Firing order=1-4-3-2 so it makes sense. Try it. Didn't work for me, though.

So after I switched #3 and #4 injector, the #4 cylinder starts to mis and #3 burns fine. So the injector is the problem.

I wonder why the freshly serviced injector works worse than before. Was the cleaning procedure too radical for 35 yrs old injector?

I hope the injector still wants to make my teener go rather than rest in peace. I really wish I don't have to get another green top.

Anyways, thanks for the advise, guys!

I sent the suspect injector back to the injector guru. And he retested it but the result was as same as before.

Here is the quote:

"I ran it from 500 rpms up to 9900 rpms and with pulse widths from 1.5ms to 17ms. I also pressure tested it to 80 psi and it holds pressure fine."

Does this mean I can expect the injector to run correctly? What other possibility you think to make one cylinder run super rich with this injector?

What is missing here? I am beginning to confuse.

Please help

You initally said #3 was not good.

You swapped #3 with #4. Then you said #4 was missing.

Did you swap injector leads or injectors themselves?

If leads, the probability is that the connector is bad (broken wire) or the wire is broken back in the sheathing somewhere.

The cleaner said the injector is fine ... It's has to be the connector or wiring.

Simple huh? More simple if you had a NOID tester to check the electrical lead. Little NEON lite blinks when the injector is fired.

Sorry, my description may have confused you.

I swapped injectors themselves and #4 cylinder is not firing with the suspect injector.

What is the culprit here?

If you moved it from 3 to 4 and the miss moved with it I would have to say that it is the injector. I assume that the injector connectors stayed at their respective positions and that you did not move the connectors with the injectors when you switched them.