4 cylinder V8 ?!

[USMC302]

OK here's the deal, changed one blown head gasket. New ignition wires, new sparkplugs. 1,2,8,6 cylinders aren't firing. When the wires are removed from the dist cap, we have spark from the terminals. When we put the wires back on, there is no spark. We take the spark plug out and leave the wire on the plug, and it fires when out of the cylinder... Car will not run off of all 8, just four. We are going off of the correct firing order and everything. Fuel pressure is set to 32lbs, timing @ 12 degrees advanced. Stock everything except fuel pressure reg (BBK), pulleys, and exhaust. Before yall ask how do I know that the spark plug isn't firing when it is in the cylinder, we were grounding each one out by putting a test light on the negative battery terminal and stabbing the top of each dist terminal through the boot. Theoreticall, the idle will go down and there will be a noticable difference when the plug is grounded out. 1,2,8,6 did not do crap. Please help

[USMC302]

no one has any ideas?! Push it in the river?

[byrnech]

Which car is it Shawn?

[USMC302]

The white GT, I swear it is getting to be more trouble than it's worth. We just finished the head gasket and now this, ever heard of it? What could it be?

[PKRWUD]

Do yourself a favor and stop ruining your plug wires. Using the same general idea, instead cut 8 1.5" pieces of vacuum hose, and insert them inbetween the distributor cap posts and the plug wire ends. Then touch the test light tip to the vacuum hose. This works much better, and won't damage your wires. Please verify your findings this way, and post the results.

Take care,
-Chris

[USMC302]

OK, I will do it this evening and let you know. But isn't the way I was doing it accurate? I mean do you think I will get different results from this? The car has no power and when we checked the terminals through the wires we got nothing, but without we got spark... I dunno, I will post the new results tonight, I am desperate.

[Stroked408]

I know this goes against all logic,but couple of questions first.

How many miles on the car? Reason I asked that does it still have the stock cam? Reason I asked that is this,some times when you put an engine back together,you could have installed everything on the exhaust stroke,in other words your car is firing 360 degrees off.

What I mean by that simple.......you think it is on the intake stroke,it could be on the exhaust stroke,sometimes this happens and lot of people never realize it.

Second if this is the original cam and the car is high mileage it could be this and this is really strange....you might have a cam that has rounded out,and cause the sporadic firing,lot of things can be wrong that is definitely a strange situation you have there.

But I am willing to bet it is 360 off,I think you are firing on the wrong stroke.

[PKRWUD]

Originally posted by Stroked408
But I am willing to bet it is 360 off,I think you are firing on the wrong stroke.

In otherwords, the distributor is 180 off. Possible, but I don't think so. It is interesting though, that the cylinders that are dead are the ones that are the same in both firing orders, and are cycled together (1&6 and 2&8). Still, I suspect that is a coincidence.

Have you verified the valve adjustment for those cylinders?

If you have done the test I suggested, and still have the same results, run a compression test, and post the results.

Take care,
-Chris

[USMC302]

OK, sorry it took so long to post back. Wiht the vacuum lines between the dist terminals and the wires, there was spark all the way around. We also had a toll that went between the wire and the plug with a light in it to show spark, again all were firing, but here is the wierd thing still....when we put the test light through the vacuum lines to ground out the spark and listen for the drop in idle there was no drop at all in 1,2,6,& 8, but we saw the spark. We pulled the plugs and they were wet with fuel, ran the compression test and had at least 140 on all. the heads that are on have had a valve job with new springs and retainers. The cam wasn't flat because we turned it over with the valva covers off and we have the same amount of movement on all. Still at a lose. We brought a scanner home but it wouldn't pick up any codes, I don't know if this has something to do with the car used to being an auto and I swapped it to a stick utilizing the same computer, I was told you could do this with no problems, and it ran fine before with that computer so i know that isn't it. Please help. Also I was told the dist being 180 off won't let the car run at all?.. Thanks

[PKRWUD]

Originally posted by USMC302
OK, sorry it took so long to post back. Wiht the vacuum lines between the dist terminals and the wires, there was spark all the way around. We also had a toll that went between the wire and the plug with a light in it to show spark, again all were firing, but here is the wierd thing still....when we put the test light through the vacuum lines to ground out the spark and listen for the drop in idle there was no drop at all in 1,2,6,& 8, but we saw the spark.

Okay, first of all, to kill a cylinder while doing it my way with the vacuum hose, you don't need to pierce the vacuum hose. Just make sure the alligator clip is grounded, and test the bulb by touching the positive battery terminal. If it lights, then start the engine, and just touch the test light probe tip to each vacuum hose (inbetween the cap and the wire(s)). That should kill that cylinder. Pull the test light away, and that cylinder should start firing again. You can test all 8 cylinders in less than a minute, without shutting the engine off.

Please try it that way, and confirm for me the results.

Take care,
-Chris

[USMC302]

Yeah, I'm sorry Chris I should have been more clear, that is exactly what i did. When I did it to the other cylinders, the idle dropped showing the cylinder stopped firing, but when i did it to 1,2,8,& 6 nothing happened. I pulled the plugs to see them and they were wet with fuel like they aren't firing. I can take the plug out while the wire is still on it, start the engine and it fires then. Seems like it doesn't want to fire while it is in the cylinder?! I was reading the other post about the guy having problems with the revving and driving, that is what I had, no power under load, so that is when I checked for spark on all the cylinders and found this problem. the wires and new and so are the plugs, don't remember if I mentioned that. thanks again

[PKRWUD]

Okay, where I'm getting confused is you said when you did it my way, you had spark all the way around. Every cylinder was firing?

Then you said 1,2,6 & 8 didn't change when grounded out, meaning they weren't firing?

So, when you did it my way, was it running on 4 or 8 cylinders?

[USMC302]

do you have a number i could call you at? Anyway if not, here is the deal, they had spark at the dist but not in the cylinder. If we leave the wire off of the dist but close to the terminal we can watch it jump to the wire from the dist, which would mean fire, but turn it off and pull the plug and it is soaking like it wasn't firing. When we ground it out the idle didn't go down any..

[PKRWUD]

So in other words, it's the same as it was before.

It sounds to me like you have a problem with the injectors in cyls 1, 2, 6 & 8. It sounds like those cylinders are getting flooded out. Do you have a fuel pressure gauge? if you do, hook it up, and get the pressure up, then shut the key off, and watch the gauge. Does it drop at all? How much, in how long?

[USMC302]

Yes, we put the pressure guage on it and set it to 35psi, when the key is turned on it jumps to 35, but goes away very quickly, we have to turn the key on again for it to read where the pressure is at. We had thought it might be the injectors before and tried to put the test light on them to see them (pulse) if you will. the ones we tried stayed solid light the whole time when we started the vehicle. So it running out quickly, does that mean stuck injectors? I do have another set of 19lbs laying around, I also have another stock Mass Air, some have told me it may be that.......

[PKRWUD]

Ahhhhh. Now we're getting somewhere. When you shut the key off, the pressure dropped quickly? I suspect you have 4 injectors that are either stuck open, or are severely leaking. This would explain why those plugs never fire, and why the plugs are always so wet. Try installing the other set of injectors that you have, and see what happens.

Take care,
-Chris

[USMC302]

I think I will worship you if that is it, I have tried everything and have been working on this for 4 and a half weeks. I will do the swap tomorrow and let you know.

[PKRWUD]

After you swap the injectors, but before you try to start it, check the pressure, and see if it still drops like it does now, or if it holds steady. Then try and start it, and see what happens.

Let me know.

Take care,
-Chris

[USMC302]

Did the swap still firing on four cylinders. The pressure slowly drops once it hits 30psi then really holds around 10 or so. It seemed to idle better once the MAP sensor was unpluged, but now I am back to shooting in the dark with this thing. Anymore ideas? Anyone?

[USMC302]

Question, could it be the pickup in the dist? I was told that when they go bad, the car won't start at all, any chance it partly went bad? Also, firing order, we have tried several different firing orders besides the correct one in the book, but nothing is working. On my notch the firing order is different than any book and I was thinking it was to the cam for better performance, could this be an odd firing order it is looking for? The car idles good, just no power and there is still no firing on 1,2,6.8. Is it coincidence that 1 and 8 are directly across from the other two that aren't firing 2 and 6?