Osmosis

today I got off work @ 0600 and started my car. I heard a knock,and then it ran like crap! sounded like the car was missing really bad! I drove home which is on the freeway for about 10 minutes. Got home and noticed that my header tube on No. 5 was glowing red. I have header wrap on my headers but I could still see the red on no. 5. After it cooled down, I pulled the plug wire and the boot was cracked from the heat. I replaced the wire, and thought that was the problem.....NOT my luck!!! I check timming and it's @ 8deg. advanced, where it's been for a long time.

So it's still missing. I"m thinking fuel, air spark. Thinking maybe one of my injectors are bad. So I tear it down, exchange injector no. 1 with injector no.5. I take it out, and no. 5 is still glowing!???

So I do a compression check, 175psi all banks! I"m thinking a burned valve, however, if memory serves me right, a burned valve will not hold pressure???right???

I changed my distributor cap, the plugs looked the same....IM stumped!!!

Can anyone help???????? P L E A S E

90rocz

That cylinder must be lean, you'll have to get a "noid" light and hook it into the injector wiring for that cylinder to see if it's getting a signal to open.
The ECM has only 2 drivers one for the pass side and one for the driver side, so I'd rulle that out.
Sometimes the injector wire gets damaged or bad connection and won't fire(open).
You switched injectors, so it's not an injector...You checked compression, it's not getting too much unmetered air...
It would almost have to be a wiring issue...

aklim

One time when I lost a fuse on the driver side, the right side was glowing because the ECM was dumping tons of fuel into the right side and it was burning out the exhaust pipe.

Osmosis

Aklim,

Thank you for the reply! I've yet to check that! Great idea, since I"ve checked everything esle! Just checked my pushrod clearances and they are perfect!???????? gonna check the fuse asap!

TY!

slimdawson

I didn't know that a primary would glow due to a lean condition. I know it runs hotter but I didn't think it would be enough to cause the primary to glow.

A rich condition cause that though due to the burning of the gases happening even after they leave the cylinder.

Also, extremely retarded timing will cause this.

Osmosis

Slim,

Yea, i tried checking the timming, shows 10 deg advanced as I run NA. Either a rich or lean condition will make headers glow. I'm concerned becasue it is only no. 5 that is glowing but compression check shows equal in all 4 cylinders on that bank?????WTF?????? Checked the lifter lift on that valve and compared it to two other valves and they are exaclty the same???????? I HATE MY CAR!

Ty for the reply!

H E L P

90rocz

Since the TPI is an MPI Bach fire system, see if you can switch #3 & #5 injector harness wires, see if the glow follows the harness.

Osmosis

90rocz,

did that today and nothing! no.5 still glows????????????? WTF?

90rocz

If the compression is within 10% of the others, and you've tried: swappimg injectors, harness wires, checked the lift for worn cam lobe, checked the plug & wires...Have you tried swapping the plug and wire??
If so, you might have to yank that head and tell me what you see...

Osmosis

I was think that myself! But I was told to take it to a particular shop and put it on a scope? This shop was recomended by the cope brothers and was told that they could figure it out. gonna go that route on monday, then tear into it if I must.........

aklim

If the problem is not in the injectors or the wire harness, where could it be? If the entire side is glowing red then we know it could be caused by the bank firing improperly. Do you suppose that the intake valve or exhaust valve is not opening properly? I mean, we know they are closing properly because you get compression but what if they were not opening all the way? You might get a rich condition that could cause that. If it opens more than it should, could you get a lean conditon? Just hashing some theories here but maybe the problem is in the valvetrain?

Dave89IROC

also, to rule out fuel sys., it is thoeretically poss. to have a restriction in the fuel rail at the #5 inj., which would show as a lean condition, not altered by inj./harness swaping

TheGreatJ

A broken intake gasket can cause a lean condition on one cylinder that will not follow an injector/harness....and there are lots of gaskets in a TPI system. While you're at that shop ask if they have a "Vac-U-Tec" or similar smoke machine for detecting vacuum leaks.


I'd almost bet on a lower runner or intake gasket.

Osmosis

I already checked for vacume leaks with some starting fluid on the mating surfaces while running. Notta. I also though about the rail being clogged @ no. 5, but then, you would think no.7 would be affected too. I'm taking it to get scoped on Monday and will go from there. Keep you all informed of the results!


TY

aklim

If it was the intake gasket, it could be leaking from one runner to another or even the crankcase. Try taking the intake manifold off and change the gaskets then.