Fresh rebuild, can’t get it to run!
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Joined: Mar 2018
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From: PA
Fresh rebuild, can’t get it to run!
Hey all! I am extremely frustrated as I have not been able to get my 1988 fc vert to start even after messing with it for about a year. A lot of work has been done with it, so I’m going to give a very detailed description of everything and then describe the problem. We aren’t novices with these cars, we have about ten years of machinist experience between us and a lot longer experience with tinkering. Any ideas would be greatly appreciated!
Alright, so the car is an 88 vert NA. We put the transmission from an 06 rx8 into the car (6 speed life!!!). With that we had to make a custom drive shaft, use the rx8 clutch, flywheel, and starter, and fab custom mounts. I don’t think this is relevant to the problem, but who knows.
The engine is the factory unit, but we put a massive bridge onto all 6 ports. Yes, 6 separate bridges, using pineapple racing templates and some of our own measurements. We also removed the exhaust sleeves entirely. The engine was rebuilt with an Atkins rotary kit, all new seals. This is the first time we’re trying to start it, so it isn’t broken in at all.
We converted it to carbeurated (don’t hate) with a racing beat manifold and a dellorto 48 ida that I found for a steal on eBay, already tuned for an rx7. We rebuilt it with a rebuild kit and checked to make sure the jets were all the recommended jets from a few rx7 specific articles I had read. We are using a holley fuel pump and regulator. However, this is our first experience with carburetors, and we don’t have much knowledge on how to tune them, but we have been messing with it so much that I would be surprised if this was the problem.
We are using a new distributor from an 85 gsl (I believe), new plug wires, new plugs, but we tried to mimic the dlidfis system. So currently, we have wires running from the distributor to GM igniters to the two factory coils, and then plug wires running from those to the two plugs. So it is only running on two spark plugs. There are no plug wires coming from the cap.
I have reset the timing many times, and tweaked it in either direction. It hasn’t helped.
Obviously all of the emissions stuff was deleted, OMP lines blocked off, etc. The only factory wiring running to the engine is the starter.
The problem is that we can’t get it to run. What typically happens is that we can get it to start initially and stay running with some carby manipulation, but once it eventually dies or we let it die it won’t start again. It will always stutter and try to start, but won’t. We mess with the carburetor settings, timing, put oil in the plug holes, atf in the plug holes, check for vacuum leaks, use starter fluid, de-flood it, none of which does anything. I know we get spark, I know we get fuel, I try to time it multiple different ways, but it won’t work. We haven’t actually used a compression gauge since the rebuild but it has very very strong sounding pulses. it also loves to shoot fireballs out of the carb and exhaust.
The only things I can guess that might be the problem are:
The carb is the issue somehow. Maybe it isn’t tuned right or something.
We overported the engine and that had some negative effect we weren’t aware of. Too much overlap doesn’t allow the carb to suck down air or something? The timing needs to be set to some crazy setting?
We totally messed up the ignition system somehow. Again, this old tech is new to us.
However if any of these were the issue, I don’t understand why we would be able to start it occasionally and let it run for ten minutes and rip it up to 10k rpm. And then as soon as it shuts off it won’t start again for the rest of the day. I’m beginning to lose interest in my dream project and I’m finally asking for help. What are we missing???
Alright, so the car is an 88 vert NA. We put the transmission from an 06 rx8 into the car (6 speed life!!!). With that we had to make a custom drive shaft, use the rx8 clutch, flywheel, and starter, and fab custom mounts. I don’t think this is relevant to the problem, but who knows.
The engine is the factory unit, but we put a massive bridge onto all 6 ports. Yes, 6 separate bridges, using pineapple racing templates and some of our own measurements. We also removed the exhaust sleeves entirely. The engine was rebuilt with an Atkins rotary kit, all new seals. This is the first time we’re trying to start it, so it isn’t broken in at all.
We converted it to carbeurated (don’t hate) with a racing beat manifold and a dellorto 48 ida that I found for a steal on eBay, already tuned for an rx7. We rebuilt it with a rebuild kit and checked to make sure the jets were all the recommended jets from a few rx7 specific articles I had read. We are using a holley fuel pump and regulator. However, this is our first experience with carburetors, and we don’t have much knowledge on how to tune them, but we have been messing with it so much that I would be surprised if this was the problem.
We are using a new distributor from an 85 gsl (I believe), new plug wires, new plugs, but we tried to mimic the dlidfis system. So currently, we have wires running from the distributor to GM igniters to the two factory coils, and then plug wires running from those to the two plugs. So it is only running on two spark plugs. There are no plug wires coming from the cap.
I have reset the timing many times, and tweaked it in either direction. It hasn’t helped.
Obviously all of the emissions stuff was deleted, OMP lines blocked off, etc. The only factory wiring running to the engine is the starter.
The problem is that we can’t get it to run. What typically happens is that we can get it to start initially and stay running with some carby manipulation, but once it eventually dies or we let it die it won’t start again. It will always stutter and try to start, but won’t. We mess with the carburetor settings, timing, put oil in the plug holes, atf in the plug holes, check for vacuum leaks, use starter fluid, de-flood it, none of which does anything. I know we get spark, I know we get fuel, I try to time it multiple different ways, but it won’t work. We haven’t actually used a compression gauge since the rebuild but it has very very strong sounding pulses. it also loves to shoot fireballs out of the carb and exhaust.
The only things I can guess that might be the problem are:
The carb is the issue somehow. Maybe it isn’t tuned right or something.
We overported the engine and that had some negative effect we weren’t aware of. Too much overlap doesn’t allow the carb to suck down air or something? The timing needs to be set to some crazy setting?
We totally messed up the ignition system somehow. Again, this old tech is new to us.
However if any of these were the issue, I don’t understand why we would be able to start it occasionally and let it run for ten minutes and rip it up to 10k rpm. And then as soon as it shuts off it won’t start again for the rest of the day. I’m beginning to lose interest in my dream project and I’m finally asking for help. What are we missing???
My mom lets me redline
Joined: Oct 2011
Posts: 600
Likes: 132
From: Cornwall, ON
Most of my post was irrelevant. I overlooked the fact that you are running a distributor. Having some compression values would help paint a picture.
Last edited by Rotary Alkymist; Dec 25, 2018 at 12:06 PM.
Welcome to the board. 
I think you have a few different things to check out. When it is idling, how high is it? Have you tried cranking the idle up to keep it running? Also, which Holley regulator did you get? You will need to use the 1 to 4 PSI regulator with that Dell'Orto. If my experiences are anything to go by, it will never run right with the 4 to 9 PSI regulator, if that's the one you have. While I'm on the subject of the Dell'Orto, I'm not convinced that is the right move for your setup. How did you set it up (jets, tubes, etc.)?
Another potential issue is you bridged all 6 ports, and that's not ideal. Also, I will assume you are running them all open, all the time ... that's probably not doing you any favors either in terms of signal strength with the throttle closed.
I would recommend checking the compression after it has warmed up and see what's going on. The hot start issue is suspect. If the compression checks out fine, then I would probably focus on the intake/carburetor.
Have you looked at the timing with a light? If you're in the ballpark of where you need to be, then that's good enough for now. The rest can only get done when you've gotten it to run consistently.
I think you have a few different things to check out. When it is idling, how high is it? Have you tried cranking the idle up to keep it running? Also, which Holley regulator did you get? You will need to use the 1 to 4 PSI regulator with that Dell'Orto. If my experiences are anything to go by, it will never run right with the 4 to 9 PSI regulator, if that's the one you have. While I'm on the subject of the Dell'Orto, I'm not convinced that is the right move for your setup. How did you set it up (jets, tubes, etc.)?
Another potential issue is you bridged all 6 ports, and that's not ideal. Also, I will assume you are running them all open, all the time ... that's probably not doing you any favors either in terms of signal strength with the throttle closed.
I would recommend checking the compression after it has warmed up and see what's going on. The hot start issue is suspect. If the compression checks out fine, then I would probably focus on the intake/carburetor.
Have you looked at the timing with a light? If you're in the ballpark of where you need to be, then that's good enough for now. The rest can only get done when you've gotten it to run consistently.
Thread Starter
Can Post Only in New Member Section
Joined: Mar 2018
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From: PA
Welcome to the board.
I think you have a few different things to check out. When it is idling, how high is it? Have you tried cranking the idle up to keep it running? Also, which Holley regulator did you get? You will need to use the 1 to 4 PSI regulator with that Dell'Orto. If my experiences are anything to go by, it will never run right with the 4 to 9 PSI regulator, if that's the one you have. While I'm on the subject of the Dell'Orto, I'm not convinced that is the right move for your setup. How did you set it up (jets, tubes, etc.)?
Another potential issue is you bridged all 6 ports, and that's not ideal. Also, I will assume you are running them all open, all the time ... that's probably not doing you any favors either in terms of signal strength with the throttle closed.
I would recommend checking the compression after it has warmed up and see what's going on. The hot start issue is suspect. If the compression checks out fine, then I would probably focus on the intake/carburetor.
Have you looked at the timing with a light? If you're in the ballpark of where you need to be, then that's good enough for now. The rest can only get done when you've gotten it to run consistently.
I think you have a few different things to check out. When it is idling, how high is it? Have you tried cranking the idle up to keep it running? Also, which Holley regulator did you get? You will need to use the 1 to 4 PSI regulator with that Dell'Orto. If my experiences are anything to go by, it will never run right with the 4 to 9 PSI regulator, if that's the one you have. While I'm on the subject of the Dell'Orto, I'm not convinced that is the right move for your setup. How did you set it up (jets, tubes, etc.)?
Another potential issue is you bridged all 6 ports, and that's not ideal. Also, I will assume you are running them all open, all the time ... that's probably not doing you any favors either in terms of signal strength with the throttle closed.
I would recommend checking the compression after it has warmed up and see what's going on. The hot start issue is suspect. If the compression checks out fine, then I would probably focus on the intake/carburetor.
Have you looked at the timing with a light? If you're in the ballpark of where you need to be, then that's good enough for now. The rest can only get done when you've gotten it to run consistently.
Thanks for the input! I believe we have the fuel pressure from 2-4 psi. And I’m a bit confused, when you talk about the bridges and Dell’Orto not being ideal, are you saying that those could be the reason why it won’t start, or that those just won’t allow us to get the most power? We are very aware of how much disapproval we would probably get from the forums about all of that stuff, but we have built this thing exactly how we want it! But if you’re saying that those could be the reason why it won’t run, can you tell me more about that? How could we check? Is there somewhere I could send the carb, tell them about my set up, and have them tune it?
Also, yes we are running without sleeves. Should I try to start it with sleeves? And I have been resetting the timing to factory as per the timing marks (I have the pulley cover that can only be put on one way so I’m sure it’s correct) and then retarding or advancing it a few degrees to see if it helps, and it never does.
As for the idle, when it does start it will idle low enough that we can actually hear the brap, but we don’t have a tach set up yet so I’m not sure the rpm. It sounds fairly low. When it doesnt start, it won’t even run on its own power, so obviously it won’t idle or rev or do anything. It’s only actually started a few times anyways.
We haven’t gone through the trouble of buying another compression gauge, but I do know that the engine ran fine before all of this, but didn’t pulse nearly as hard as it does after the rebuild. That’s why I haven’t considered the compression to be the problem. Is it still worth a check?
I was asking which Holley regulator you have. It's been years since I've messed with this stuff, but when I finally got around to tuning my Dell'Orto, there were two different regulators offered by Holley (and they looked identical) the only difference was their rating range. One ends at 4 PSI the other starts at 4 PSI, if you got the latter, the car will not run right. I was basing my fuel pressure on the RB recommendations, and that was when I learned Dell'Orto's run on less than 4 PSI (contrary to what they said). Once I got the 1 - 4 PSI one, I was able to get the pressure right. Your Holley pump should be more than enough for you, but the carb needs you to get the pressure IT wants. They are sensitive to it.
And I’m a bit confused, when you talk about the bridges and Dell’Orto not being ideal, are you saying that those could be the reason why it won’t start, or that those just won’t allow us to get the most power? We are very aware of how much disapproval we would probably get from the forums about all of that stuff, but we have built this thing exactly how we want it! But if you’re saying that those could be the reason why it won’t run, can you tell me more about that? How could we check? Is there somewhere I could send the carb, tell them about my set up, and have them tune it?
My comment was more inline with the latter. I can't think of any reason you shouldn't get it to idle with it though. I respect that you have the car set up the way you want it, however, that mindset can be a road to unnecessary issues. I'm not saying it will be, but it very well could be. I haven't personally messed with many bridges, assisted with a few here and there - and I've never built one for myself (yet) - but I do know the manifold matters. Are you using the wrap-around setup or the Lake Cities - style? Again, none of this matters of for getting the car to idle, but in the long term for when you get it to run, it will matter.
As far as sending the carb to someone, I have no idea who messes with Dell'Ortos on that level in the rotary world any more - especially for a bridge. You can look around, maybe post something in your Regional forum, but I'm not fully convinced you will find anyone in a timely fashion, if at all. You're going to have to get right with being THAT guy for yourself. My advice to that end is study Weber carb theory and apply what you learn to your Dell. I started out hating mine, but eventually I grew to like it. However, they are obsolete, there is no getting around that.
Also, again, post what you have in there (idle, fuel, air, tubes, etc.) - that will matter as well. Even if I am unable to help, someone else probably can.
Sleeves - You can try putting them in and see if it does anything for idle. It should yield a stronger signal, so for now, I think it can only help.
Timing - use a light. I built an engine once and the damn thing would not start for a few hours, and when it eventually started, it had a pretty pathetic idle, and ran like dookie. I set and reset the timing many times in that process, and when I finally put a light on it, it was way off. I figured out that whenever I installed the distributor, it would somehow move over a tooth. When I finally corrected for it, it started perfect, it idled and ran perfect! Use a light.
Try turning the idle up - get some air moving. Get it to idle and respond to throttle. Worry about details after that.
My concern is is that it's harder to start after it gets some heat in it. So whenever you can, do a test just to eliminate that something is wrong with the motor itself.As far as sending the carb to someone, I have no idea who messes with Dell'Ortos on that level in the rotary world any more - especially for a bridge. You can look around, maybe post something in your Regional forum, but I'm not fully convinced you will find anyone in a timely fashion, if at all. You're going to have to get right with being THAT guy for yourself. My advice to that end is study Weber carb theory and apply what you learn to your Dell. I started out hating mine, but eventually I grew to like it. However, they are obsolete, there is no getting around that.
Also, again, post what you have in there (idle, fuel, air, tubes, etc.) - that will matter as well. Even if I am unable to help, someone else probably can.
Also, yes we are running without sleeves. Should I try to start it with sleeves? And I have been resetting the timing to factory as per the timing marks (I have the pulley cover that can only be put on one way so I’m sure it’s correct) and then retarding or advancing it a few degrees to see if it helps, and it never does.
Timing - use a light. I built an engine once and the damn thing would not start for a few hours, and when it eventually started, it had a pretty pathetic idle, and ran like dookie. I set and reset the timing many times in that process, and when I finally put a light on it, it was way off. I figured out that whenever I installed the distributor, it would somehow move over a tooth. When I finally corrected for it, it started perfect, it idled and ran perfect! Use a light.
As for the idle, when it does start it will idle low enough that we can actually hear the brap, but we don’t have a tach set up yet so I’m not sure the rpm.
We haven’t gone through the trouble of buying another compression gauge, but I do know that the engine ran fine before all of this, but didn’t pulse nearly as hard as it does after the rebuild. That’s why I haven’t considered the compression to be the problem. Is it still worth a check?
Timing - use a light. I built an engine once and the damn thing would not start for a few hours, and when it eventually started, it had a pretty pathetic idle, and ran like dookie. I set and reset the timing many times in that process, and when I finally put a light on it, it was way off. I figured out that whenever I installed the distributor, it would somehow move over a tooth. When I finally corrected for it, it started perfect, it idled and ran perfect! Use a light.
Also, get your trailing ignition setup. My car ran like dog crap while I had just the leading plugs firing - had to use the cold start assist on the DCOE, crank for a while, and even then it wouldn't idle right. With the trailing setup it was much easier to start and idled by itself.
The trailing coil can be setup a lot like the leading - signal from the dizzy fed to a GM ignitor hooked up to the coil. Just run the lead from the coil to the distributor cap, then connect the trailing wires to their spots on the cap.
Also, like the guy above suggested, put the sleeves in if possible. I'd only recommend this if you still have the stock lower manifold, that way you have a way to keep them from vibrating around and opening without you knowing.
Good luck.
EDIT:
Also, when you get the trailing setup you can run the stock tach wire off the negative terminal of the trailing coil. To do this without cutting up the stock harness, I cut the connector off the stock trailing coil itself and connected my new tach wire to the yellow wire on the connector (which connects to the yellow/blue stock wire on the main harness). Then I put a ring terminal on the new wire and hooked it up to the negative stud of the trailing coil. Worked like a charm.
Last edited by Kellis; Jan 2, 2019 at 04:26 PM. Reason: Tach info
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