1995 Lincoln Continental - V8 Misfires

[Stewart Levy]

1995 V8 twin cam engine #1#5 won't fire; have replaced coil and plugs and wires. Pulled injectors and spray tested them they are working. Spark plugs are wet when pulled Have 150 PSI compression all cylnders. Brain is farting on old info think I read about an EGR problem with the intakes on this engine. I have pulled the EGR valve and oil tested it for leaks it is sealing. I do remember the old 5.0 carb spacer plate causing a similar problem!

Any Ideas?

[steven kiser]

alrighty now, compression is good. i'm going out on a limb here and assuming that you've checked for spark on the two cylinders. the only egr issue i can think of off the top of my head on the newer fords is the v6 where the port in the intake plugs. you've tested the injectors and they're ok. hopefully there was interrupted spray and not constant. i've seen random injectors stick open. if you've tested and have no spark i'de suspect the pcm or a broken wire. 1&5 are the two front cylinders hence the broken wire. now on a wild note, did someone else do any work on this car just prior to it coming into your shop. 1&5 seems to be more than random. i'll look into it more and get back.

[Stewart Levy]

Add Info to search for the cure. Have pulled the rail and swapped the injectiors from 2& 6 and the problem is still here. Also have switched the conection on the injectiors. Side to side. Also have swapped the plug wires to reverse the flow throught the plugs. Have good noid light pulse and the injectiors are not leaking down on flow test with Off car Ram tester with fuel pump hot . Base fuel pressure at idle is 38 psi And when the pump is dead headed pressure goes to 60 psi. Then I let off dont want to blow the pump hose. I had a simmilar car with low fuel pressure that acted like this. When I dead headed the pump the cylinders came back. Called the owner and pried out of him that he had run regular in the car for two tanks and this problem appeared, He said he has run high test since and the then when it didn't fix itself he gave it to me! ????

[fortknoxx]

so,,,,,,, do we have spark?
when switched to 2&6, did problem stay with 1&5?
for the heck of it. switch out the plugs. maybe the box was dropped 1 or 15 times between the warehouse and your door. the center core electrode might be broken inside the ceramic. only switch 1 plug. see if you still have the same problem. this will eliminate the plugs.

[steven kiser]

egr ports in intake may be plugged

[Stewart Levy]

We replaced the plugs after the compression test . We did a fire test on the coils we enven switched the coils. Thats why I asked if anyone had run into this problem on the Board before I'm still inclined to think that it has to be something in the intake system. The plugs come out wet and black. So I would think that the engine is not getting enough good air to set the fire! I found an article on the 3.8 with a note about the egr pipes comming loose and causing this problem but have never ran into it. I tried a company on this problem that bills you for the fix and thay ran me around for two hours and then they sent me the bill and the car is still not fixed! This is the second time and I vowed that this won't happen again! I'm not the chair fix type. I get my hands dirty every day! My tech has posted it on IATN No response yet!

[brianp87]

I think you may need to dig deeper into the intake or egr system and start tearing it apart

[ricmorin]

If you suspect the intake, do a running compression test. That'll check volumetric efficiency.

[Stewart Levy]

OK I'll Bite How in the world do you do a running compression test? I've never heard of this!

[fortknoxx]

i had an issue with my 93 crown vic. the tube near the back of the intake was rusted & clogged shut

[ricmorin]

OK I'll Bite How in the world do you do a running compression test? I've never heard of this!

What you do is check the cylinders while running, purging the air from your gauge every 4-5 puffs. You ground the spark and disable the injector on the cylinder tested. The number at idle should be 1/2 static compression. You then snap the throttle and record that reading which should be about 80% of static. Too low and there is an intake restriction, too high and there may be an exhaust restriction. Takes a little time, but when all else looks good......

Here is a link..... http://www.misterfixit.com/dyncompr.htm and if you do a search on iAtn there are some articles on the procedure too.

[Rich]

Are you saying that 1 and 5 don't fire period Or are 1 and 5 misfiring?

Your thoughts are that wire 1 and wire 5 are on reversed on the towers.

[Stewart Levy]

The #1#5 Cylinders come on line at 1500 rpm, The missfire counters stop the cylinders actually start to work! the skip comes out of the engine. The O/2 sensors voltage comes into range for the cruise speed, at idle they are off the scale.
I got mad at the car last night and took it to my friend at Lincoln He's got a tech thats been with lincoln 20 years. I just got the call. The tech says the cams are flat on the #1 #5 intake lobes that hes seen this before. I called the guy before I took it a week before and he didn't rember this but now after the check out charge he tells me this! I guess I need to find a new guy to talk to! $80. Bucks latter! I still don't think this is so i'm pulling the valve covers!

[ricmorin]

It makes sense. Mechanical misfires often are worse at idle and smooth out at higher rpms. This includes volumetric issues like low compression and intake issues like vac leaks and valve problems. Electrical and fuel caused problems can usually be felt at higher rpm's. Can't wait until you take those covers off. I wanna know!

[wbuxton]

Plastic intake?

[Stewart Levy]

metal intake!

[Stellers Garage]

Dont leave us hanging.....

[Stewart Levy]

Monday she comes back in the shop!

[Tim Martin]

If I'm not mistaken, those 4.6L engine camshafts had pressed on cam lobes. They have been known to slip, or as one post suggested maybe even wore off. So far, I have not seen these cams wear off a lobe but I expect it's possible. They also had a problem with the rockers coming off. I have seen an engine replaced already when all that was wrong was two rockers came off on the old engine. Pulling the rocker cover may reveal the problem.

Good luck! Keep us posted.