99 3.1 SFI issues

[95sporty150]

Hey guys, Im new to this site, but have long had a problem with my 99 cutlass. Its the 3.1 auto, and had the intake gasket failure, I replaced the gaskets bolted it all back together, cranked it up, and it had a horrible skip/metal tapping noise. My code reader said cylinder number 1 misfire, so replaced the plug and wire and nothing, took it back down, realized a buddy who was helping me put the wrong pushrod in place and it bent the pushrod,and cracked the rocker, i replaced the rocker and bought 2 new pushrods. Now it has a skip again, this time its a multiple cylinder misfire, I replaceed all the plugs and wires twice and nothing, got fed up with it and it has set for a year, got it back together again last night still has that skip, I replaced one of the coil packs because I thought I found the problem,no. Here is whats odd, I can pull any one plug wire (one at a time) and the skip doesn't change, the motor acts exactly the same, if i pull 2 its stumbles worse, Why would pulling any one wire not change the stumble? Somone told me the crank trigger or camshaft sensor may have gone bad, anyone here got any ideas? sorry for the long post

thanks
Wesley

[CNCguy]

My vote is on a bent valve from when the pushrods were incorrectly installed. Do a compression check on each cylinder.

[95sporty150]

I was afraid of that but why would the stumble not change if I pull one plug at a time, but will if I pull two? Also the code reader reads Multiple cylinder misfire.that being said what is the average or within range pressure on these motors?

[3400-95-Modified]

around 170-180 PSI max... Thats what my rebuilt 3400 put out, you'll probably see around 160 depending on mileage.

Double check and make sure you have all your plugs plugged into the ignition module too, if you missed the crank position sensor plug then that would definately cause a misfire.

[95sporty150]

thanks guys, I'll run a test and keep you all posted.

[95sporty150]

did a compression check all are in the 150-165 range. any ideas? I recorded it on video as well. It smells like raw gasoline at the tailpipe, you can hear the skip in the vid

http://www.preplayground.com/media/99cut.wmv

[3400-95-Modified]

Try replacing the ignition module if you havent yet.

[davida1_hiwaay_net]

Could an injector-connector be dislodged? Listening to the AVI of the engine running, it sure sounds like there is something mechanical going on in there; either causing, or in addition to the misfire.
How could it have avoided a bent valve or broken valvespring with the valvetrain going into such a bind?
The misfire is a regular, repeating miss. In other words, a dead cylinder. It is surprising that disabling the ignition doesn't pinpoint it.
I've had very bad luck pulling off wires on a DIS ignition. A better way is to install a piece of bare wire under the boots of each coilpack tower (where each of the 6 wires leaves the coilpack). It only needs to emerge a little bit from the boot. From this point, touch a grounded wire to each of the exposed bare wires to ground out each cylinder. This will avoid disrupting the spark to the "other" cylinder powered off the coil with one wire disconnected. As well as prevent frying the coilpack or module from running with no-load.

[95sporty150]

Try replacing the ignition module if you havent yet.

that was my next route, I bleed ford blue and know all about ignition modules going bad.

Could an injector-connector be dislodged? Listening to the AVI of the engine running, it sure sounds like there is something mechanical going on in there; either causing, or in addition to the misfire.
How could it have avoided a bent valve or broken valvespring with the valvetrain going into such a bind?
The misfire is a regular, repeating miss. In other words, a dead cylinder. It is surprising that disabling the ignition doesn't pinpoint it.
I've had very bad luck pulling off wires on a DIS ignition. A better way is to install a piece of bare wire under the boots of each coilpack tower (where each of the 6 wires leaves the coilpack). It only needs to emerge a little bit from the boot. From this point, touch a grounded wire to each of the exposed bare wires to ground out each cylinder. This will avoid disrupting the spark to the "other" cylinder powered off the coil with one wire disconnected. As well as prevent frying the coilpack or module from running with no-load.

I to hear the mechanical noise but thinks its a product of the skip, not the cause(though i could be wrong) I just installed a new(used) fuel rail on the car as I bent the old one and could not get it to fit corectly. The exhuast smells like gas/ a little sulfur, I still think the issue is in the timing, or ignition. ill will let you guys know, my next route is just to buy a remand head and go from there. This car is draining out of my other project.

[Carlspike]

Have you checked the catalytic converter?

[95sporty150]

here is an update, I used the compression tester on my 95 f150 and noticed somthing, even with the pressure released the needle would get suck, so I got a new one, re-ran a test on my cutlass, guess what, cylinder # 3 has 0 pressure in it, here is why :

http://www.preplayground.com/media/99cut2.wmv

I don't know if you can tell or not, the valve is not seated all the way up. I dont know if the valve is bent or the spring is broken, if the valve were bent won't my head be useless,or will the guides have taken the beating? I think steel rubbing aluminum won't be pretty. Either way, which is the better option? Just buy a remaned head with valves installed, or just get a new spring package and valve and just replace the one? Im leaning towards a reman'd head. opinions?

[Ducatiman]

Did you check for a "lazy rocker" a cam lobe may be wiped out could not listen to vid on dial up

[Ducatiman]

forget what i just said

[davida1_hiwaay_net]

Man that is a bummer. It sounded like a mechanical issue on the first video.
It's hard to tell what is going on by the video file. I couple of good close-up pictures of the valve and spring area would be better.
Look at the piston and see if there are any nicks in it. If the piston is nicked (indicating valve contact), then the valve is most definately bent.
Either way, that valve has to come out. If you don't already have one, AutoZone will rent you a spring compressor. Just take that one valvespring off and look at it for breakage. Put the valve back in the head with no spring and spin the stem while looking at the valve head. If it is bent you will be able to tell immediately.
If the bend is slight, your valve guide is probably OK. With the spring removed, see how bad the valve binds in the guide.

[torq455]

yeah, if you missed plugging in an injector, then unplug that spark plug wire, it's gonna miss just the same. try unplugging other wires. it sounds like maybe one cylinder is sporatically missing then partially hitting at the exhaust pipe. weird.