88 Z51 C4 update

Wonder if a full 360 degree timing tape on the damper would give an idea of what's going on. Like, at idle, a timing light triggered off of #1 cylinder should read about 12 degrees of lead. What should #3 give? A timing map would probably be useful, is the #3 cyl something like 180 degrees behind #1? I pulled 180 out of an oriface but maybe this makes sense; figure out how many degrees behind #1 each cylinder should be and run a timing light and compare to a timing map and figure out if the thing is drastically out, late, etc etc.

Or this is a waste of time. Someone tell me what you think. Please!

You don't have a 4/7 swap cam in there per chance, do you?

Javelin wrote: You don't have a 4/7 swap cam in there per chance, do you?

We've asked that a few times, he says no.

pres589 wrote: Wonder if a full 360 degree timing tape on the damper would give an idea of what's going on. Like, at idle, a timing light triggered off of #1 cylinder should read about 12 degrees of lead. What should #3 give? A timing map would probably be useful, is the #3 cyl something like 180 degrees behind #1? I pulled 180 out of an oriface but maybe this makes sense; figure out how many degrees behind #1 each cylinder should be and run a timing light and compare to a timing map and figure out if the thing is drastically out, late, etc etc. Or this is a waste of time. Someone tell me what you think. Please!

This is where i'm personally leaning, that it's a timing issue, but i'm crossing my fingers it's just the vacuum idea that was thrown out.

92CelicaHalfTrac wrote:

Javelin wrote: You don't have a 4/7 swap cam in there per chance, do you?

We've asked that a few times, he says no.

Just because the box it came in says no doesn't mean the cam itself isn't. I've seen that more than once.

Javelin wrote:

92CelicaHalfTrac wrote:

Javelin wrote: You don't have a 4/7 swap cam in there per chance, do you?

We've asked that a few times, he says no.

Just because the box it came in says no doesn't mean the *cam itself* isn't. I've seen that more than once.

True story.

I believe Sir Bob has found the culprit, or at least something that was horribly wrong, but i'll let him share when he has the time.

If it's the cam was in the wrong box and is a 4/7 swap I'm going to spit my soda all over the laptop!!!

Javelin wrote: If it's the cam was in the wrong box and is a 4/7 swap I'm going to spit my soda all over the laptop!!!

Lol no, not that.

Intake leak. One really big leak and at least one small leak. When I say big... I mean I don't know how it idled. Give it up for GM IACs compensating!

Javelin wrote: If it's the cam was in the wrong box and is a 4/7 swap I'm going to spit my soda all over the laptop!!!

If it was a 4-7 swap cam 4 and 7 would be dead and no others. 7 is good. 7 fires like it should. So it can't be a 4-7 swap. C'mon peeps, use your noggins!

Woo Hoo! So how's it running now with all 8 firing?

The 305 in my old Malibu would idle on 5 cylinders. Would even move the car around. Had to retire the 305 when it got to the point it didn't want to go up hills anymore.

I haven't FIXED it yet. Need to pick up a new intake gasket, drain the coolant and get some better bolts.

Intake is re-sealed. No more leaks. Took a couple mi utes for the idle to set. Still on 5 cylinders. I'm done.

Noooooooooo.. dude that sucks. I wish you weren't so far away, I would offer to help you poke at it for a while. But 200 miles is a bit far for that.

Wish I had something to offer but I don't. We all feel your pain though and hope you get it figured out.

i'm guessing crank to cam timing, cracked head, or bad cam.

Can you get your hands on a boroscope to look into the cylinders? Might see something?

I'd pull the injector and fuel rails, and make sure the injectors are all firing properly. I know the LT1 injectors can be really problematic. Wet plugs doesn't necessarily mean there is enough fuel - if it's super "lean", it won't fire. I could be full of it: testing injectors is easy, move injectors around and see if the misfire moves. Of course, if you have a wiring problem to the injector, that requires a different test.

Bobzilla wrote: Intake is re-sealed. No more leaks. Took a couple mi utes for the idle to set. Still on 5 cylinders. I'm done.

Dude! I've been thinking about your problem in the back of my mind all day. Have you checked the actual injector harness to make sure that each harness is going to the correct injector? I know on the 5.0 Ford it's super easy to swap those things since some of them are the same length! Grab a multi-meter and a timing light and get looking, or just start swapping them. It makes total sense...

I'm not sure how intimate you are with the SBC, but since you are having such problems with this, I figured I'd throw it out as no one else has mentioned it.

How are you numbering the cylinders on the engine? SBC alternates cylinder order right to left, with #1 being drivers front of the engine and #2 being passenger front. Not like Fords, which number front to back with #1 being passenger front and #5 being drivers front.

I can't help but thing either your number is wrong or the firing order is wrong (all the same really). You can have fuel, compression, and spark, but if it's not lighting off at the right time, you're going going to end up with wet plugs.

Bring it up on the compression stroke for #1 and go over the cylinder number and wire order again.

18436572 clockwise on the distributor.

edit: I'm looking at your first video and the way you have the plug wires laid out looks all wrong. I'm not sure what you have done, but #1 on the distributor should be on the driver side of the engine. It appears you may have it on the passenger side. It's a bit dark to see the orientation of the distributor as well. Or you've got a very unorthodox way of routing the plug wires.

In reply to WhiteLX:

I finally glanced at the video, doesn't look copasetic. And what you said WhiteLX. (dr.side) 1-3-5-7, (pass. side) 2-4-6-8... 18436572

this should all be noted in any SBC manual

cam timing too

I once spent a week trying to sort out why my Bronco wouldn't start after a seemingly simple intake and carb swap. Turned out I was timing by the #5 cylinder rather than #1 cylinder. A WEEK! So it could totally be something simple like that, please don't toss the car over it.

fasted58 wrote: In reply to WhiteLX: I finally glanced at the video, doesn't look copasetic. And what you said WhiteLX. (dr.side) 1-3-5-7, (pass. side) 2-4-6-8... 18436572

Doesn't appear to be helping in this case.......IIRC, the order was different on the last tpi I delt with.......then again, that was a decade ago, but that t/a did the same E36 M3 bob's did.....ended up being wrong order on the cap.

But "OH NOES, TEH INTRAWEBZ AND CHILTONS DON'T LIE".......

Here's a new pic from this morning.

Yes, I tore down and rebuilt a SBC without the basic knowledge of how the cylinders are labeled. I am that stupid.

The wires that I originally had on there were parts house wires that were 2 miles too long even thought they were supposedly spdific fit for an 88 Corvette.. To keep them from rubbing against places they shouldn't I had to get creative with my wire routing.