Engine not running on all cyls. - help!

[FL911]

Ok, here is my problem/question:

1981 911SC 3.0 - 14 months in the process and I finally got the engine in last night..........triple checked everything and she fired right up.....but after checking the timing it sounded like it was only running on 4 cylinders or so.
We checked the spark and all of the cylinders are firing so I was wandering what else it could be?

For the record everything is new: plugs, plug wires, cap, rotor, all EXCEPT for the fuel injectors........could this be the problem?
Does the fuel distributor have to be timed with the engine and if so how do I do that?
I am quite sure I have all of the fuel inj. lines in the same order as they were before but just in case does anyone have the correct orientation of these?

I need some help from you all so I can get this thing running right! Other than this I have no leaks and it should run strong when I get this issue taken care of.

Thanks for any input!!!
Frank

[vash]

your fuel lines can be in any order..no big deal. if i were in you situation, i would narrow down the search. when it happened to me here is what i did. i let the car get cold. then i got a spray bottle filled with water. i started the car and immediately got under the car and started spraying the exhaust. it happens very fast, but you quickly find out which cylinder is not firing. the water will not steam away on the dead cylinder. then check for spark and fuel at that hole. on my car, i found the spark plug wire was defective. you can even yank that fuel injector, lift the sensor plate, and see if it sprays (into a clear plastic jar/bottle).

[stlrj]

Originally Posted by FL911

Ok, here is my problem/question:


For the record everything is new: plugs, plug wires, cap, rotor, all EXCEPT for the fuel injectors........could this be the problem?

Thanks for any input!!!
Frank

Sounds like you crossed your ignition wires, something I have done many times without even trying.

[T77911S]

very good idea with the spray bottle.
+1 on crossed wires

was the motor just rebuilt?
if you suspect the injectors, pull all 6 and place each in its own container. lift the air plate as said above and check each. when done, compare fuel quantaties by weight of volume. i had one that has nearly half the weight as the others. i dont know a tolerance, but as long as they are not way off.

if still no go, do a compression/leak down on the dead cylinder.
valve adjustment?
carbon keeping the valves from closing?
very bad air leak to cylinder?

[Gunter]

Frank:
Check the firing order 1-6-2-4-3-5 and remember that SC-distributors run ccw, NOT cw like the Bentley says.

You can remove the injectors and soak them in Injector Cleaner fully submerged for 24 hours and then blow them out.
To pop the injectors out, spray a little WD-40 onto the O-ring, then pry them out carefully with the help of 2 open-end wrenches underneath the cap-nut.

[FL911]

Tonight I will check these items and get back with all of you.

Thanks again!

[FL911]

Everything is perfect, back together and runs very strong!

Thanks to all

[stlrj]

Originally Posted by FL911

Everything is perfect, back together and runs very strong!

Thanks to all

Glad to hear your success. So what was it?

[Gunter]

FL911,
What was the problem?

[vash]

yea, what was the problem/fix?

[T77911S]

you get the feeling he does not want to say

[Hladun]

This is the worst kind of post. There's a plea for help in the title. People offer their best help and then the poster can't be bothered to add to the body of knowledge by saying what happened. FL911, people help because they expect to learn!

[FL911]

I posted this on this forum as well as the engine rebuilding forum and I forgot to enter the resolution on this one.

Hladun - don't get your panties were they should not be......I have this thing called WORK so pipe down son!

The problem was: After pulling all 6 plugs the #2 and #4 were clean as could be so I new they were not getting fuel.........I pulled both of these injectors and they were clogged.....I cleaned them in my ultrasonic parts cleaner as well as injector cleaner and then blew them out with light are pressure.........put it all back together and she runs extremely strong!!!!!

Thank you all for your input and ideas. And I AM SORRY for not posting sooner after all it was just last night that I took her out to the test drive.

Again............Thank you!!!

[vash]

excellent!

[j_mancini]

Originally Posted by FL911

I posted this on this forum as well as the engine rebuilding forum and I forgot to enter the resolution on this one.

Hladun - don't get your panties were they should not be......I have this thing called WORK so pipe down son!

The problem was: After pulling all 6 plugs the #2 and #4 were clean as could be so I new they were not getting fuel.........I pulled both of these injectors and they were clogged.....I cleaned them in my ultrasonic parts cleaner as well as injector cleaner and then blew them out with light are pressure.........put it all back together and she runs extremely strong!!!!!

Thank you all for your input and ideas. And I AM SORRY for not posting sooner after all it was just last night that I took her out to the test drive.

Again............Thank you!!!

FWIW, I had a similar problem and it turned out to be the little screens inside the banjo bolts on the fuel distributor. My mechanic said those screens are a factory install and aren't absolutely necessary, provided you keep the system clean! He claims they occasionally clog and create the same problem you had.

[Hladun]

Well if it was only to dump on me, at least we got an answer!

[Mitch Leland]

I had a similar problem after having my engine out for a clutch job and tranny work. I had my injectors serviced. When it started I had 2 dead cylinders, finally took it to my mechanic and he tapped the injectors on the dead cylinders and everything was wonderful. That's all it took. One nice thing he did was to label the injectors so the richest injectors were installed on the hottest cylinders.

[FL911]

I want to thank all of you again for all of your help and interest in the resolution!!
Hladun- I did not mean to "dump on you"! All is good, I hope.
It just took me a tad longer to make sure this was the problem....I do not want to enter false information and possibly mess someone else up! I was up very late for numerous night trying to figure this out.

I changed the oil/filter last night and took her out again, running better and better.


Thanks again

[stlrj]

"Gloria in excelsis Deo"

[Gunter]

"AL-HUMDULILA"

And Hare Krishna to be safe.