Dead cylinder? I feel sick!

[manoa matt]

http://en.wikipedia.org/wiki/File:Fiat_ ... el_702.jpg

[Europa]

More proof that Fiat quit on this car after 82,knowing they couldnt get it any better!!

Ya had to stick that in there!

Good luck Craig. I hope it's the injectors. Even if it's the head gasket, you get to refresh the top end and you're good to go for another 30 years!

[mdrburchette]

do a leakdown test like Matt is suggesting. You can even do it yourself and it'll pinpoint exactly where you're losing power.

[ga.spyder]

Couldnt get a comp tester this am.I did get a pressure tester ,and pressurized the cooling system to see if I had any leaks from the head.Nothing.It held 14 lbs for 10 minutes.I dont know exactly what that means.. Will do a compression test tomorrow.I will have to read up on a leak down test?

[mdrburchette]

You set your engine to top dead center and connect your compressed air hose to your spark plug hole with a gauge to check to see if you are losing pressure. You can hear where the compressed air is escaping and determine where your problem lies. Do this to each plug hole to see which cylinder is the weakest.
This better explains it:
http://en.wikipedia.org/wiki/Leak-down_tester

[ga.spyder]

I am going to do the compression test first.I am starting to think(hope) that it might be a fuel delivery problem.It is definitely #4 that is dead.It has good spark and we will see re. compression.

[majicwrench]

Gotta say, quit changing parts andfigure out what is wrong. If it blows dowel across yard, compression is OK. Did you actually check for spark at plug?? Did you actually confirm that injector sprays fuel?? Valve springs broken??
HG least likely culprit. Don't jump to conclusions or guess.
Keith

[ga.spyder]

Hey Keith,I am trying to approach it slowly.I have borrowed a compression guage ,so I will do that today.Yes,I do have spark at the plug,and had it when I limped it home.I thought maybe it was weak,so I changed out the ignition parts to eliminate that.I am certain that it isnt ignition.The injector is activated ,but I havent confirmed if it is spraying fuel or not.I thought I would do the compression test first,before having to pull that entire fuel rail.Is there a way to test the injector w/o pulling the whole system apart.It is the #4 ,which ,of course,the worst one to get at.Valve spring is a definite possibility.If I have a broken spring ,wouldnt that show up with the comp.test? I am glad you posted,as I had thought about sending you a p.m. as to where to start diagnosing.

[narfire]

I'm guessing injector. Have you disconected the injector when running? No Change???

A long handled screwdriver from above will pop the injector conection off.

[ga.spyder]

I havent Chris..and that is so simple why didnt I think of that??

[majicwrench]

That cylinder is already dead, so disconnecting injector, well, it's still gonna be dead.

Broken spring may or may not show up with compression test. Like I said, and you mentioned earlier, if you blew dowle across yard you certainly have compression. If need be is simple to pull covers and see if you can visually spot issue or see if you can depress spring easily.
When testing compression watch how gauge pumps up, should be same on all 4. Sometimes with a broke spring/flat cam whatever odd issue the gauge, even tho is shows compression, will do funny things. Also, cranking engine with plugs in and ign disconnected, you should have a nice, even, smooth cadance. RRRRRRRRRRRRRRRRRRRRRR. If you have compression issues, cam issues, spring issues, will usually change the cadance. RRRerRRReRRRerRRRer..
Have you wiggled inj connector at #4 with engine running??
Yes you can check inj in vehicle. Pull two connectors, check resistance of two inj, obviously they shold be same. Do you have a fuel prssure gauge?? If you do hook it up. Now get two jump leads and just fire the inj from the battery. One jumper to pos one to neg, doesn't matter which way. OR go to NAPA and get a spare inj connector they are cheap. When you hook + and - to inj it will fire, you should be able to hear a little piss and if you have a gauge hooked up yo will see pressure drop. Again,if you have two inj to play with you can compare the running to the non-running inj.
ANd if your at parts store pick up cheapy stethescope, and listen to all 4 inj. Again, they should allsoud same. Inj that are plugged often "thud" more than "click".
Keith

[ga.spyder]

Thanks Keith.I did the compression check.They were all about the same,120 psi+- dry and 150 psi+- wet.Isnt that pretty good for a car with 80K+ on it?The motor sounds the same when cranking on all 4 and I would say the guage pretty much went up the same.I will go ahead and pull the cam covers and by look and feel,check the valve springs next.I dont think I have another injector(I will look),and I dont have a fuel pressure guage.Funny,using the stethescope to listen to the injectors the #4 did seem to sound a little different.I have played with the connection to injector with the engine running...no change.
Keith ,thanks a lot.As a mechanic ,I am a pretty fair carpenter!! To get advice from a pro mechanic that is familiar with these cars is invaluable to me.I will keep everyone posted.Thanks to everyone for all the feedback.I am pleased that it doesnt seem to be a head gasket!!

[azruss]

stop all the tap dancing and fix the damn injector

[maytag]

To get advice from a pro mechanic that is familiar with these cars is invaluable to me.

sheesh! NOW you've done it!

There'll be no living with him for WEEKS now!

[majicwrench]

There's no living with me anyway, just ask my ex-wife.