missing/rough running

[8cam]

Work has meant I have not been able to get into the garage and really dig into the problem, luckily I have another car to drive. I finally got some time this afternoon (what a gorgeous fall day here) and pulled the plenum for the first time, took about an hour.

Do I get some kind of scout badge for this right of passage?

So yeah, it's dirty. I verified that all the plug wires are right around 11-12k ohms, way under the FSM's 30k limit, so they are fine. There's no doubt the coils are original, 24 years old with almost 50k on them. The 5/8 coil has a crack in the body, and those were the two showing the strongest spark!

In any case, I've read you can't really "test" a coil without a very expensive piece of equipment, but is there a decent indicator? The 4/7 coil ohms out to 5.35k and is the lowest by a decent margin. The others are right around 5.7k.

I also found a split intake manifold gasket and a bad/oily MAP sensor tube, so those will also be replaced. Jerry is getting a call.

[Schrade]

Good job breakdown. Been there done it. Take your time cleanup; nothin' like clean hardware to rule out intermittents, and non-DTC issues, etc., .................

I bet a suggestion to wipe the sec vac plumbing from me would NOT be the only one to do so.

You doin' NCRS with the Z there Mark?

[8cam]

Only if NCRS means drive the crap out of it, and don't care if it gets dirty. Nah I'm just not a show guy, even though I enjoy going to them. I'd much rather drive than figure out the proper swoop of the grease pencil mark on the rear subframe, because Ralph was working the line that day.

I'll definitely be doing some cleanup and check the various systems while I'm in there but it actually looks pretty good under the dirt. Means it hasn't been messed with too much.

[mgbrv8]

8cam here are the photos of my plenum pull I hope they are helpful any questions feel free to message me

https://www.facebook.com/media/set/?...1&l=8f46fa4533

Dave

Originally Posted by 8cam

Work has meant I have not been able to get into the garage and really dig into the problem, luckily I have another car to drive. I finally got some time this afternoon (what a gorgeous fall day here) and pulled the plenum for the first time, took about an hour.

Do I get some kind of scout badge for this right of passage?

So yeah, it's dirty. I verified that all the plug wires are right around 11-12k ohms, way under the FSM's 30k limit, so they are fine. There's no doubt the coils are original, 24 years old with almost 50k on them. The 5/8 coil has a crack in the body, and those were the two showing the strongest spark!

In any case, I've read you can't really "test" a coil without a very expensive piece of equipment, but is there a decent indicator? The 4/7 coil ohms out to 5.35k and is the lowest by a decent margin. The others are right around 5.7k.

I also found a split intake manifold gasket and a bad/oily MAP sensor tube, so those will also be replaced. Jerry is getting a call.

[We Gone]

Mark, Sorry I missed your call Sat. looks like you are official now. pulling the plenum looks intimidating at first but as you now know its not to bad. Now that's its off take your time as others have said and do some clean-up. I may not know as much as some of these guys but I have done 6 pulls so far and I know where to get answers got to love the forum. I would cover the ports on the injector housings asap (the first thing I do after plenum removal) you definitely don't want anything to get in.

Let me know if you need any help be happy to drive up and lend a hand.

[Hog]

Originally Posted by 8cam

Only if NCRS means drive the crap out of it, and don't care if it gets dirty. Nah I'm just not a show guy, even though I enjoy going to them. I'd much rather drive than figure out the proper swoop of the grease pencil mark on the rear subframe, because Ralph was working the line that day.

I'll definitely be doing some cleanup and check the various systems while I'm in there but it actually looks pretty good under the dirt. Means it hasn't been messed with too much.

He is implying you should remove your Port Throttles. In other words"If your not doing NCRS, you should remove your PT's", in his opinion.

[Dynomite]

Originally Posted by mgbrv8

8cam here are the photos of my plenum pull I hope they are helpful any questions feel free to message me

https://www.facebook.com/media/set/?...1&l=8f46fa4533

Dave

You did some things no one else has done in those photos
What did you do to the water pump impeller on the lathe?
I see you got around the air locked water pump by installing a brass pipe plug on the top side of the water pump?
I went what I think is an easier way by blocking off the TB coolant at the Injector Housing with an Aluminum Plug each side.
I have taken apart "other" AC compressors....what did you do to rebuild your AC compressor?
I see you have a photo of Auto Air New Parts....is that what you did?
I see you did clean the orifice screen on the High Side.
I have also replaced the armature bearings in LT5 starters as you apparently also did?
Did you replace anything else in the starter other than clean up the contact points in the Solenoid?
You obviously replaced the Purge Canister finding Canister filter material scattered through the system

Great stuff there Dave
Can I copy a photo or two that I do not have in my own collection?
I am already using your starter in parts photo in my Starter Reconditioning Thread with credit to you for photo

Thanks...... I am studying all your photos for any additional secrets you may have
I may have an additional question or two but I think most is in your very informative posts which I catch in -Solutions-

[mgbrv8]

You did some things no one else has done in those photos
I am sneeky
What did you do to the water pump impeller on the lathe?
The aftermarket pumps impeller was making contact with the block so I had to do a light cut to the impeller for clearance
I see you got around the air locked water pump by installing a brass pipe plug on the top side of the water pump?
I went what I think is an easier way by blocking off the TB coolant at the Injector Housing with an Aluminum Plug each side.
I have taken apart "other" AC compressors....what did you do to rebuild your AC compressor?
I see you have a photo of Auto Air New Parts....is that what you did?
Ahh good eye, But I wrote a big write up for the next Heart of the Beast Newsletter so I dont want to spoil anything
I see you did clean the orifice screen on the High Side.
I have also replaced the armature bearings in LT5 starters as you apparently also did?

Did you replace anything else in the starter other than clean up the contact points in the Solenoid?

Again its going to be a future articular for the Heart of the Beast Newsletter

You obviously replaced the Purge Canister finding Canister filter material scattered through the system

Great stuff there Dave
Can I copy a photo or two that I do not have in my own collection?
I am already using your starter in parts photo in my Starter Reconditioning Thread with credit to you for photo

Yes you can all I ask is that you put my name on them with Microsoft paint or something, David Hetrick

Thanks...... I am studying all your photos for any additional secrets you may have
I may have an additional question or two but I think most is in your very informative posts which I catch in -Solutions-

[8cam]

Originally Posted by Hog

He is implying you should remove your Port Throttles. In other words"If your not doing NCRS, you should remove your PT's", in his opinion.

Tempting, but even though I'm not a purist I do like the secondary throttle system. It's part of the character of the car, and that power key is a great conversation starter. I'll be keeping it for now, just want to get back on the road.

[8cam]

Finally a follow up to this ridiculously long saga. I'm on a deadline for a big client by Monday morning, so I'm working all weekend. Well after working for 7 hours today I hit a big milestone, and decided it was time to take a little break. My parts came in yesterday so it was high time the ZR-1 got a little quality time.

I was certain at least one coil was bad and I was also certain I didn't want to dig under the plenum for a good long time, so I replaced all 4 coils, all plug wires and all spark plugs. The wires and plugs were probably overkill since they were reasonably new, but it was cheap insurance. I took my time and I used this AWESOME page from Big Country Corvettes, really a great 1-2-3 for the job.

http://www.jasik.com/ZR1_Plenum/Plenum.html

Also a tip from Steve (We Gone). When reinstalling the plenum, don't put the gaskets in right away. Put the plenum in place, connect all the electrical stuff underneath, and a few other things. Then when you're ready to bolt the plenum down, lift it just a little and slide the new gaskets in there right before putting the bolts in. You don't want to damage those gaskets by jockeying the plenum around trying to hook everything up. Steve was 100% right about this.

It took me about 1.5 hours to replace the coils, spark plugs (gapped and anti-seize), and carefully run the new plug wires. Then about an hour to replace the plenum and get everything hooked back up. Really not too bad a job. First start took a few seconds to build fuel pressure and then chugged to life. First few seconds were a little rough running while everything cleared out, and a TON of white smoke out the tailpipes - residual from a little getting down into the intake manifold when I pulled everything.

Then the test drive. HOLY HELL THIS CAR RUNS LIKE A RAPED APE!! Wow. It's very clear that the coils must have been going bad for a while and I just didn't notice, but DAMN it pulls like a demon now. It's running better than it ever has in my possession, really really happy.