exhaust manifold smokes

[capowered240]

whenever I start the car sounds like it is missing. I have to keep giving it gas to keep it going, but then when I let off it dies. Also after about three minutes of holding my foot on the gas I noticed smoke coming from the exhaust manifold. When I put hold my hand above the manifold it feels like it been driven all day but it hasn't. It's been sitting for about a month now. I just got done changing out all the gaskets on the exhaust side. I can't seen to figure out what's wrong. Any suggestions would help.

[themadscientist]

the running problem is causing the high exhuast temps. pull your plugs and find the suspect cylinder. After that determine if it's fuel or spark that is missing. If they look similarly f-ed up see if disconnecting the air flow meter does anything. That is a good place to start. Let us know what you find and I am sure everybody will help narrow it down.

[capowered240]

Alright, I pulled the plugs and this is what they look like. Then I checked to see if there all getting spark. they are. I put everything back in and disconnected the maf. Started it up and it still sounds like it is missing. Could a bad o2 sensor make it do that. I'm still using the o2 sensor that came on the engine.

[redamnavit]

Maybe its the picture, but it looks like #1 and #3 and running way rich, but #4 looks so clean I'd question if its ever seen fuel at all. I'm curious what TMS has to say about this.

[capowered240]

I had tested all the injectors a couple of months ago. All the injectors tested good except for #4 injector. So I bought some injectors and changed out #4 injector. I rechecked them and they all tested good (2.6 ohms). Also what I did was unplug #2 and #4 injector plugs, started it up. it still was missing. I plugged those back in and unplugged #1 and #3, started it up. It did start up, but it still was missing. So i'm thinking all the injectors are still good because it started up ,but it still was missing. I unplugged the maf and it didn't make or sound any different. It still had that missing sound. I'll test the injectors again. Is their any other way of testing them to see if they work at all?

[capwred]

to check to see if the o2 is bad just unplug it.

mine went bad and it did something like yours is doing.so i unpluged it and i got to get a new one.anyone know which one will work?

[capowered240]

I'll pickup a new o2 sensor tomorrow. It needs to be replaced anyway because it is the sensor that came with the motorset. The o2 sensor to get is from a 86' 200sx. It's about $40 at advance auto.

[biosehnsucht]

I had a cyl w/ dead coilpack for a few weeks.

that cyl was so clean inside from the continuous fuel bath... the sparkplug was mint looking, the piston brand new.

check the coilpacks.

[themadscientist]

with the engine running unplug an injector. If the running does not get worse that is suspect. You can put a screwdriver on the injector and put the handle to your ear to listen for the solenoid click. RBs you can hear with the darned hood shut!

[capowered240]

all coilpacks are good. I pulled each spark plug out to see if it is getting spark. They all are.

[float_6969]

I think 2&4 aren't getting good enough spark. You can pull the coilpack and get spark, but when it's inside the combustionchamber, the air movement may "blow" the spark out.

I would start the car and then have a friend keep it running.Start w/injector #1 and start unplugging them, one by one. I have a feeling that one or more cylnders will have little to no effect from being unplugged.

If you try this and it doesn't do anything. Repeat with the coil packs. Simply dissconnect the plugs on each pack one by one.

If THAT doesn't have any effect, then I would check the ignitor. That procedure is listed in the FSM. If that checks out OK, then try the CAS. It could also be that your timing belt jumped a tooth.

Try all of that and get back to us.

[capowered240]

I unplugged each injector plug while the car was running. It didn't make a difference. I did that with the coilpacks also and it still didn't make any difference. I pulled the spark plugs out again and the still look the same as the pic above. I replaced the o2 sensor today. I have another ignitor so I changed the ignitors out. It still didn't make a difference.

[F3600]

ohm each wires of the ignition system.

Ecu to ignitor / ignitor to each coilpack and see if something is not ohming properly... look like something is not working right in 2 cylinders.

If everything is okay try ohming each injector wire from the ECU to each injector plug.

Do the same with the CAS

Look for Ecu trouble code too in mode 3

read the diagnostic part of the FSM procedure are all in there.

look in your coilpack, inside the red rubber boot, if there are still a spring with a small rock wich contact the sparkplug maybe its missing... seem like a very unusual problem.

good luck

[capowered240]

When I got this motorset, I never did a compression test on it. So I did one today and the results are:

#1 160#2 0#3 160#4 0

[F3600]

Ouch.. thats bad .. seem like you will need a tear down

[themadscientist]

bent valves, sorry dude

[sideways danny]

When I got this motorset, I never did a compression test on it. So I did one today and the results are:

#1 160#2 0#3 160#4 0

bent valves, seized lifters, very badly worn valve seats or holes in your pistons. could even be a blown head gasket.

[capowered240]

If it is bent valves. Where can I get those from? I'll check it out this weekend.

[capowered240]

I took the valve covers off and didn't notice anything odd. In the FSM it says to set the timing on the compression stroke. On the compression stroke all the intake and exhaust valves should be closed, right? When I line up the the marks on the intake side, #1,2, and 4 are closed. #3 is about a 1/4 of the way open already. On the exhaust side, #1,3, and 4 are closed. #2 is about 1/4 of the way open. Is it suppose to be like that? In the FSM, where it says to set it on its compression stroke, are they talking about just on the #1 cylinder or on all cylinders?

[F3600]

its the first cylinder in front of the timing belt

[dattodude]

Bent valve man.

You need to take the head off.

Zero PSI is a valve sealing problem. You won't see the damage from the cam side of the head. Somebody hadn't replaced the timing belt at the service interval, and it's either slipped a few teeth, or snapped sometime in the past.

This is not a weekend fix. I certainly wouldn't be driving the car like that.

Go find a good condition replacement head from somewhere if you want a quicker fix. Otherwise pull the head off and have a look, and go from there. Make sure that you know where the timing belt goes back on. The dots on the belt should match the dots on the pulleys (top 2 and crank)

[capowered240]

Well I got the head off today and ya those valves are bent. Would a ca16de head work, or is it different. If not I will probably bring it to a machine shop, or if you know of anybody that has a good head lying around and they want to sell it let me know.

[float_6969]

I would personally have the head you've got repaired. Did you look at the pistons and make sure that they weren't damaged?

[capowered240]

Ya, their still in good shape. Nothing happened to them. Is changing the valves yourself pretty easy or do you have to take it somewhere.
Modified by qwade25 at 8:56 PM 1/17/2006