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Tech / General EngineIs your car making a strange sound or won't start? Thinking of adding power with a new combination? Need other technical information or engine specific advice? Don't see another board for your problem? Post it here!
Hello everyone, so i bought a 1989 rs swapped to a carb 355(350 bored over) with a cam.
When i got it it had a decent amount of problems so i kept fixing it up, now that i've fixed most of the problems i decided to check my timing, i took the cap off after i cranked to TDC and the rotor was pointing tword the windshield, no wonder my car felt slow.
So i went to my job today on my day off to mess around with my distributor, considering the owner of the car did a lot of butchery i figured he just didn't know how to put the distributor in right.
I put the timing mark to tdc and pulled the distributor, rotated the oil slot put the distributor in with the rotor facing roughly at cyl 1, dropped the distributor bolted it down. Car wouldn't crank. messed with the timing both retarding and advancing nope. Tried to give it gas it backfired through the carb bad, it almost sounded a gun went off. So i said ok we'll maybe it's 180 out, pulled the distrib up a bit rotated the rotor 180 dropped it back in. Tried to start again no start, this time it's shooting gas through the carb again tried advancing and retarding the distrib still no start at all. put it a tooth over still nope, 180 a tooth over nope again. After over 2 hours of messing with it it still would not start, so i put the car back at TDC took the distributor out and pointed the rotor at the windshield again, dropped the distributor in. Cranked the car and it started right up.
How can my cam possibly be so off that i have to turn the cap all the way tword the windshield for it to even run? My car lacks power, it also at high rpms(not exactly sure the rpm range, stock and aftermarket tach dont work) it starts to hesitate almost like a really fast lean backfire but fuel pressure doesn't effect it much timing does. It sounds like my car is misfiring too andd when i'm off the gas the car rocks forward and backward.(i'm assuming cause of the severe firing order difference) My car doesn't have a lot of power, it's ok but doesn't really pull unless i'm going 50-60 already.
My old car with a little over half the hp definitely pulled harder, could this be causing all these problems? If so aside from ripping the engine out how can i fix this?
If I'm understanding your post correctly, you do realize that with the timing mark on the crank being at TDC on the timing tab, the engine could be on the compression stroke at either No. 1 or No. 6? This would explain the 180 degrees off thing.
As mentioned above, the timing mark can be TDC on #1 or #6.
Take the #1 spark plug out. You can bar the engine over until a gust of air comes out the plug hole. A simple trick is to put some tissue over the hole and watch for it to be blown away.
Once that happens, the timing mark should be very close to lined up. Bar the engine over until it is without going all the way around or you'll have to go all the way around again. You are now at TDC #1.
Now as for the distributor, the #1 plug wire can be positioned anywhere on the cap as long as the rotor is pointing at the #1 plug wire terminal but #1 should be roughly at the 5 o'clock position when looking at the distributor from the front. If it isn't, pull the distributor and do what you've already done to get it into that position.
Now put the cap back on and start putting the plug wires back on making sure the #1 plug wire goes onto the proper terminal that you've already determined to be #1. Firing order is 18436572 in a clockwise rotation. Be careful that you don't mix up 5 and 7 because they are both beside each other on the cap and in the head.
That should now be close enough to get the engine started. The timing will need to be advanced slightly to set the base timing but it should still start.
Don't forget after you line up the timing mark at TDC with the #1 cylinder at TDC (check for air or use a screwdriver to feel for the piston). You may need to move the oil pump shaft to align with the distributor gear. Use a long screwdriver and position it correctly. Finally after the distributor is in correctly I usually just position it in the center of its adjust-ability and that gets me close enough to start.
The timing mark is TDC on BOTH #1 & #6, at the same time.
THIMK... it's a 4-stroke engine; that means each cyl fires on ALTERNATE revolutions. It's also an 8-cyl; that means 4 cyls fire on one revolution (timing mark comes to TDC once), the other 4 fire on the next revolution (timing mark comes to TDC AGAIN), the first 4 fire on the next, etc.
The likely reason your car started when the mark was up and the rotor was pointed backwards was, the engine was at the #6 firing instance of the mark, NOT the #1 instance.
As Alky hinted at, you need to find the instance of the timing mark alignment that's at the end of the #1 compression stroke (#1 firing). The other instance when it comes up is at the end of the #1 exhaust stroke, and is also #6 firing.
The timing mark is TDC on BOTH #1 & #6, at the same time.
THIMK... it's a 4-stroke engine; that means each cyl fires on ALTERNATE revolutions. It's also an 8-cyl; that means 4 cyls fire on one revolution (timing mark comes to TDC once), the other 4 fire on the next revolution (timing mark comes to TDC AGAIN), the first 4 fire on the next, etc.
The likely reason your car started when the mark was up and the rotor was pointed backwards was, the engine was at the #6 firing instance of the mark, NOT the #1 instance.
As Alky hinted at, you need to find the instance of the timing mark alignment that's at the end of the #1 compression stroke (#1 firing). The other instance when it comes up is at the end of the #1 exhaust stroke, and is also #6 firing.
Yea i understand what you guys are saying. I know that it could be either on exhaust or compression stroke at TDC, but here's the thing that makes no sense. I had it facing twords cyl 1 at TDC and the car wouldn't start at all. So if say for instance it was firing on exhaust stroke initially when i turned the rotor 180 degrees shouldn't that have made it fire on compression stroke?
Where i had it initially when i was starting it initially it backfired through the carb but with a bang and i think i heard some backfiring in the exhaust but really low. When i turned it 180 from where i set it initially it started to just shoot gas out the carb. I put it back 180(so again where it was originally) When i advanced the timing a lot like i had to turn the rotor over 90 degrees it ran but barely. So then from there i tried to advance it some and still nothing.
As soon as i put the mark back to TDC and put the rotor facing up it started right up.
Also before i even messed with the rotor i had found at where the rotor was pointing initially(before i took the distributor out) when i put the #1 spark plug wire where the rotor was pointing and set up the firing order accordingly it was spewing gas out of the carb. Once i put the firing order about 4 steps back it started right up again.
Like I already said, Where #1 plug wire is on the distributor could be anywhere. Providing the cam and timing chain are installed correctly, with #1 piston at TDC, the distributor can be dropped with the rotor pointing wherever you want by simply turning the pump drive to line up. You could just as easily have the rotor pointed straight at the firewall but the only way the engine would run is if you started putting the plug wires on with #1 at the post straight at the firewall. Just because the #1 plug is at the post in the 5 o'clock position doesn't mean that plug is going to be firing as the piston is coming up to TDC on the compression stroke.
Like I already said, Where #1 plug wire is on the distributor could be anywhere. Providing the cam and timing chain are installed correctly, with #1 piston at TDC, the distributor can be dropped with the rotor pointing wherever you want by simply turning the pump drive to line up. You could just as easily have the rotor pointed straight at the firewall but the only way the engine would run is if you started putting the plug wires on with #1 at the post straight at the firewall. Just because the #1 plug is at the post in the 5 o'clock position doesn't mean that plug is going to be firing as the piston is coming up to TDC on the compression stroke.
That's the thing tho the car will only run with the rotor pointing at the firewall and the #1 plug at 5 o clock lmao. With the rotor straight at the firewall and the #1 plug lined up with it the car was shooting gas out of the carb. When I put #1 back to 5 o clock it started right up. My point is when the rotor and #1 plug wire are in sync the car will not start.
While you're at it, check the timing mark accuracy. Then once you have that right, come back and I'll tell you how to drop the dist in properly. Which I've already posted about a million times; maybe this time the mods will make it a sticky. "How To Time A Distributor".
This may not make a huge difference, but- What kind of carburetor and distributor are you using? I'm assuming that you went from fuel injection to carbureted?
If you used a electronically controlled Q-Jet carb, with a vacuum diaghram style distributor, or if you used a Holley (or older style Q-jet) carburetor with a stock electronic controlled style Camaro distributor without the vacuum canister, you will not find total joy in any event. The car should still start but you will not have good performance. On some of the early computerized cars with Q-Jets, the computer, carb and distributor all talk to each other via wiring. Older school setups without computer use "regular" carburetors and distributors with the vacuum ignition advance canister controlled by engine vacuum. You have to have the styles of distributor and carb matched up to each other.
But you still have to follow the advice from above before you match the dizzy and carb.
10-04-2016, 10:00 PM
