Running on 3 cyl,I need some advise!!

[ga.spyder]

My beautiful,bulletproof 82 has a serious issue,for the first time since I brought her home(3 1/2 years).I have been dealing with a very slight,low speed intermitent miss.Changed plugs,no change.I bought the elect. ign. tune up parts(mag p/u,rotor,cap) and changed them this morning.The car was running fine,I had to move it for garage space.Did the swap and the car is running awful!!The #4 cyl isnt firing.I can pull the wire,and motor runs the same.Swapped wire...same story.Put a plug in the wire and there is spark,although it looks a little weak?Changed the plug,still no hit.Pulled the coil,checked the module and all connections.Nuttin!
Please,any advise would be welcome.I am truly depressed over this.My daughters prom is tonight,and they wanted to use the car for pix,like we did w/ my son.I am going to head back out,and put the old parts back on(the mag p/u was fine no frays) and see if that helps.Oh yeah,I checked to see if that injector was clicking and the connection was ok,seemed fine.Thanks guys.
Craig

[ventura ace]

If the spark looks weaker than the spark for the other plugs (check to see), then it pretty much narrows it down to the cap, wire, or plug for that cylinder that isn't working or possibly the rotor.

If the spark looks similar to the other plugs, I'd check compression on all 4 cylinders to rule out a valve or ring issue. If that's good, the injector would be suspect.

Call Ron. He knows how to mess with those troublesome '82's. Or call me, and I'll try to wing it.

Alvon
805-338-1767

[ga.spyder]

Thanks Alvon.I put all the old parts back,and it is the same.It is definitely #4,I can pull the wire and it runs the same.I tried different wire ,plug ,cap,p/u combinations.No change.I dont have a compression guage,but I will borrow one.I am leaning(hoping) for an injector.I will give Ron a call,as I dont know if I can test them w/o removing plenum and taking the injector out.
The look on my daughters face when I told her we wont have matching prom pix.... You wouldnt think that it is a coencidence for this to happen after doing the ignition tune,but it seems to be.Maybe someone will have another idea.
Craig

[ga.spyder]

Sorry..just realized this is posted in 'related',instead of proper catergory.I can pull the connector to the #4 injector,and the engine runs the same.I apparently am not getting fuel to the cyl.I do have spark.There is also 12 volts at the connector for the injector.Any ideas??

[narfire]

To pull the injector you have to pull them all while still on the rail if you still have the original injector hose. There is not enough play to pull just the one unless you have injector clamps on the hose.
REMEMBER to stuff a rag into the cross member black hole also perhaps on the starter and other electrical things down there. I use a pair of bent nose pliers to help with the injectors.
sounds like an injector might have decided to go TU but perhaps an airleak around the injector from a bum seal. I guess you have swapped plug leads around and no difference- still #4 eh. The rail comes off relativly easy just a 10mm around the fuel reg and the main fuel supply line and the 4 nuts holding the injector backing plates. #4 can get fiddley though.
Funny, the seriousness of the snag is in direct proportion of the need for the car to work. A couple of hours to test and re and re the injectors.
Chris

[So Cal Mark]

with the engine running, listen to the injector with a stethoscope or long screwdriver touching the body of the injector. If you don't hear a noticeable clicking the injector is not firing. If you don't hear the click, tap on the injector body with the engine idling. If the inj is sticking, tapping on it can free it up. You'll need an ohmmeter to check the injector. I've had some success getting them unstuck by using jumper wires to the injector; one to ground and one to battery voltage. Momentarily touch the power wire to one inj terminal while the other is grounded and continue until the injector starts clicking

[rlux4]

When I read the first post I thought "here's an easy one". Usually it's just a matter of what did you last do when it started to run bad. (Which I know you already thought of.) But it sounds like it's a case of very strange coincedence. Did you check for injector pulse at #4? If you haven't bought a noid light yet, you can give it a cursory check with a mechanics stethoscope, should be able to hear a distinct clicking. I never had luck with a test light or volt meter for checking injector pulse. It's pretty weak and quick.
If it's pulsing and you definitely have spark, then you may have to pull the injectors to see if that one is plugged up.
Bummer man. Bad timing, huh?
Ron

[ga.spyder]

Thanks for the advise,guys.I really appreciate it.I do have spark,the engine is running on 3 and when I disconnect the plug to injector 4 ,it doesnt change a beat I do have power to that inj.plug(test light),and it is clicking when I use the stethescope to listen.Maybe plugged ?? I thought I had it when I found the ground on the back of the plenum very loose...no go.Bad timing.I have a big event in 2 weeks ,so I really need to get this done.Do I have to remove the plenum to get at the rail/inj? Looks like very tight quarters!
Craig
I though it was a no brainer too,Ron.No such luck.I took the red 76 over to the pix spot,and they posed with it Even though it''clashed with her dress''

[spider2081]

I think I would check compression before pulling the fuel rail.
If you do pull the fuel rail Napa and Autozone carry HELP cards with universal parts. Card 90100 has both the large and small injector seals for about $9 for all 4 injectors and 2 spares.

Also I have used fuel hose 5/16" 8MM from McMAster Carr pn 5645K23 and pinch clamps 5435K15. Not sure if the pinch clamps is an over kill. I forgot the part number for the pinch clamp pliers. Heating the hose ends with a hair dryer of paint striping hot air gun makes assembly easier.

[mdrburchette]

I say shoot it and jump in your carbed model. They may not be as "reliable", but they sure are easier to diagnose!

[ga.spyder]

Well....the day has gone from bad to worse !!Went back to the garage to see what I could do.Started the car ...and the starter wont stop spinning.I had to pull the battery to stop it.What the hell?? I am not much of a drinker,but I am hitting a few tonite !!! Thanks for the info on the HELP cards,and I will get a guage to check the compression before I go much further.Now I probably have to do a starter first!
I did take 'old reliable' to the picture session and guess which car is probably going to The Mitty.

[narfire]

The injector rail comes off without pulling the plenum. #1-3 are easy and #4 bit fiddley but you can see the nut by looking down from the top. There is a mounting nut/bolt with a rubber bushing at the pressure reg and the main fuel supply line and the rail comes out. you should have small seals at the tip and the larger ones that hold the injector in place with the intake manifold.
Pull the electrical and the grounds as well to remove.
I have 1/2 dozen spare injectors and only need four if you need one. I was going to send them all down to the place in WA to be checked over.

[So Cal Mark]

low voltage will cause the starter to stay engaged, charge your battery and make sure the cables are tight.

[ga.spyder]

Thanks Chris and Mark.I will charge the battery...I did a lot of cranking today.I will let youknow re. an injector,Chris.I got frustrated today and will go after it tomorrow.
Craig

[narfire]

Yeup, nows not the time to be mucking about with the engine while the run for lord Stanley's cup is on
Go Canuckle heads