Need advice, car won't run!
Drifting
Joined: Nov 2002
Posts: 1,665
Likes: 1
From: Ontario
First, be a hero and learn how to make a QJet run properly. All the chicks will dig you. 
Second, sounds like a vacuum leak.
Have you put a vacuum guage onto her yet?
A vacuum leak means less airflow through the carb meaning less atomization of the fuel hence dripping instead of a fuel mist. This would get worse with lower engine speeds - just a hypothesis...
Second, sounds like a vacuum leak.
Have you put a vacuum guage onto her yet?A vacuum leak means less airflow through the carb meaning less atomization of the fuel hence dripping instead of a fuel mist. This would get worse with lower engine speeds - just a hypothesis...
Thread Starter
Instructor
Joined: Oct 2004
Posts: 173
Likes: 0
From: Hattiesburg MS
Originally Posted by BigBlockk
With the vacuum advance disconnected and the engine running, advance the timing slowly. The idle speed should rise. Don't use a timing light for this, go by the sound of the engine. Now, back off on the idle speed screw on the carburator. Keep increasing the advance and lowering the idle speed until it will idle smoothly at 700 or 800 rpm. Now look into the carburator to see if you still have nozzle drip.
I'm thinking the ring on the ballencer has slipped and is giving you a false timing reading. You may have had the idle speed cranked up on the carburator because the timing was way retarded.
This will give you enough to think about for now (translation: I worked all night and need to go to bed). Try this and report your findings.
Good luck.
BigBlockk
Later.....
I'm thinking the ring on the ballencer has slipped and is giving you a false timing reading. You may have had the idle speed cranked up on the carburator because the timing was way retarded.
This will give you enough to think about for now (translation: I worked all night and need to go to bed). Try this and report your findings.
Good luck.
BigBlockk
Later.....
Wow........what a concept! I have been so caught up in getting everything set to just the right measurement that I totaly forgot I can tune a car by ear. When I read your post I felt pretty stupid for not thinking of this myself............after all, in my younger days I didn't have timing lights and vac pumps only wrenches and screwdrivers! 
I followed your advice and ...............SHE RUNS! Not really well yet, still allot of tuning to be done but it will now stay running at 900 RPM in park and even runs when put into gear. RPM drops to about 600 in gear. Real flat going into secondaries and still dripping fuel from the choke side nozzle. However, running well enough to go sideways from dead stop and get wheelspin when she hits second gear! I suspect a bent hanger on the secondary side and maybe a bent rod up front. Going to replace these items and see if things get better. After she was running fairly well I put the light back on and with the advance hooked up got 4 deg at idle and 8 deg of advance at WOT. Measured vac to be about 17 at 900 RPM.
Please tell me if any of this sounds way off! Thanks to all for the suggestions given!
Drifting
Joined: Sep 2004
Posts: 1,959
Likes: 1
From: North Bend Ohio
Well, good to hear you had some success. That always helps to give you more confidence. Now, back to work.
Ya say ya got a flat spot when the secondaries come on line huh? Do you know how to set the tension on the secondary air door? If so, you may want to tighten it up 1/8'th of one (1) turn. CAUTION: You must go easy on this, it is rather touchy. If you tighten the spring too much it could be damaged. Take the car out and see how it feels. If the bog is reduced but still there you may want to take up some more (like maybe 1/16'th of one (1) turn) on the air door. I wouldn't go any farther than this.
The timing readings still seem strange to me. I think you still need to find out if that damper ring has moved or not. For the time being though you could increase the advance two (2) degrees at a time until you can hear it detonate with the engine under load at full throttle. This is generally between 2300 and 3000 rpm. If it's gunna rattle, this is where it's gunna happen. When you reach this point back it off two (2) or three (3) degrees and lock it down. While you're doing this it's a good idea to take note of how the engine starts. Does the starter have a hard time spinning the engine over when it's warmed up? If so, back the advance off a fue degrees. This is as far as you can go and still start the engine without having trouble. The small block Chevy runs best with about thirty six (36) degrees total advance all in by 3000 rpm.
What we have done to this point is not really tuning. It is more repair work than anything else. You can not tune an engine that does not run.
By the way, could you give us some info on this engine (headers, little bit of a cam and so on)?
Good luck.
BigBlockk
Later.....
Ya say ya got a flat spot when the secondaries come on line huh? Do you know how to set the tension on the secondary air door? If so, you may want to tighten it up 1/8'th of one (1) turn. CAUTION: You must go easy on this, it is rather touchy. If you tighten the spring too much it could be damaged. Take the car out and see how it feels. If the bog is reduced but still there you may want to take up some more (like maybe 1/16'th of one (1) turn) on the air door. I wouldn't go any farther than this.
The timing readings still seem strange to me. I think you still need to find out if that damper ring has moved or not. For the time being though you could increase the advance two (2) degrees at a time until you can hear it detonate with the engine under load at full throttle. This is generally between 2300 and 3000 rpm. If it's gunna rattle, this is where it's gunna happen. When you reach this point back it off two (2) or three (3) degrees and lock it down. While you're doing this it's a good idea to take note of how the engine starts. Does the starter have a hard time spinning the engine over when it's warmed up? If so, back the advance off a fue degrees. This is as far as you can go and still start the engine without having trouble. The small block Chevy runs best with about thirty six (36) degrees total advance all in by 3000 rpm.
What we have done to this point is not really tuning. It is more repair work than anything else. You can not tune an engine that does not run.
By the way, could you give us some info on this engine (headers, little bit of a cam and so on)?
Good luck.
BigBlockk
Later.....
Thread Starter
Instructor
Joined: Oct 2004
Posts: 173
Likes: 0
From: Hattiesburg MS
You are exactly right BigBlock, lots and lots and lots of work yet ot do. After work today I checked the secondary rod hanger. As I suspected, found it to be bent. I guess this was someone's voodoo, half a** idea to correct the idle problem or rich mixture condition at some point. The rear hanger holes center line should be .740" (41/64) below the top of the rear choke wall, according to information in one of the papers written by Lars. Found it to be .855" on my carb. Took it off and got the holes within .002" then reinstalled. Took it for a spin and the results were great. No more bog! Huge wheelspin from dead stop and it now hits second so hard the rear slides out a bit. The idle became even better and its not even close to being as rich anymore. I think that with the hanger bent this badly it threw the geometry off and the rods were actually binding sideways in the jets. Found evidence of this on one of the rods, it had a wear mark on only one side as if it had been cocked in the jet. If this is what was going on, the engine could have been getting fuel from the seconday side of carb even at idle. Only had about an hour to play with it today......wife is getting a little pissed about how much time I am spending with the car. Thought it best to just call it a night after this adjustment.
Mixture is still rich. This weekend I plan to remove the primary rods, put them on static wheels, and measure runout to see if they are bent as well. I suspect the choke side rod to be bent. Still getting nozzle drip on this side and this mixture screw is ineffictive. Will also dig deeper into timing this weekend, will let you know if I find evidence of the damper ring slipping.
As far as I know the engine is stock. My father-in-law never told me anything about an aftermarket cam. It has stock manifolds but he did have true dual pipes put on with Sonic Turbo mufflers. He also had a shift kit put in the transmission, hits the gears pretty hard (second gear is almost violent). Don't really know what all he did to the engine. Find stuff every day that makes me say WTF did he do this for! Strange stuff like a nail with electrical tape around it in a vac port for a plug and two bare wires hanging from under the dash to blow the horn with! The list of stuff like this goes on and on so who knows whats been done to it. All emissions stuff has been removed or disconnected except PCV valves, maybe this was an engine mod to him.
The main reason I wanted to get the engine running fairly well was so that I could trust it to make about a 35 mile trip this weekend. Have a buddy with a steam cleaner and vehicle rack. Plan to take the 2" of dirt and oil build-up off engine and trans so I can see what I have to work with.
Mixture is still rich. This weekend I plan to remove the primary rods, put them on static wheels, and measure runout to see if they are bent as well. I suspect the choke side rod to be bent. Still getting nozzle drip on this side and this mixture screw is ineffictive. Will also dig deeper into timing this weekend, will let you know if I find evidence of the damper ring slipping.
As far as I know the engine is stock. My father-in-law never told me anything about an aftermarket cam. It has stock manifolds but he did have true dual pipes put on with Sonic Turbo mufflers. He also had a shift kit put in the transmission, hits the gears pretty hard (second gear is almost violent). Don't really know what all he did to the engine. Find stuff every day that makes me say WTF did he do this for! Strange stuff like a nail with electrical tape around it in a vac port for a plug and two bare wires hanging from under the dash to blow the horn with! The list of stuff like this goes on and on so who knows whats been done to it. All emissions stuff has been removed or disconnected except PCV valves, maybe this was an engine mod to him.
The main reason I wanted to get the engine running fairly well was so that I could trust it to make about a 35 mile trip this weekend. Have a buddy with a steam cleaner and vehicle rack. Plan to take the 2" of dirt and oil build-up off engine and trans so I can see what I have to work with.
