Hey guys, I'm new to this forum and could use some help. I have a 1985 delta 88 body with an 83 or 84 Olds 307 in it. When I had the engine out I removed and blocked all the smog and emissions crap on it, looks too messy, and put an Edelbrock 1405 carb on it with a brand new vacuum advance distributor from an older 307. I've got the car running, but any time you load the engine she sputters horribly and tries to die. I set the timing at 20 BTDC around 1500 rpms with the vacuum advance plugged off and it helped, but she still runs like a 3 legged dog. This is my first experience with a carbureted engine, and I did rebuild the carb with the help of my old Automotive instructor to make sure I didn't miss anything. I checked vacuum at idle and she's only running about 11 in HG, which is way too low. Checked compression on all cylinders and they were good. Even replaced intake gasket and sprayed all around the carb base and intake checking for a leak. At this point I'm stumped. Did I set the timing incorrectly or do I have another problem that I'm missing?
Olds 307 problem!
- Thread starter 85delta88
- Start date
- Status
First set the timing at a idle around 750-850 pull it back to 16 degrees initial timing.now for the carb edlebrock usually has these set pretty good out of the box but the two mixture screws in the front of the carb if not touched put your vacuum gauge on a port that has constant vacuum not pull each screw out 1/4 of a turn at a time until you have your highest vacuum reading then that should be set plus just a thought what are the condition of the plugs and are they the right plugs for the car Oem plugs are best way too go the two mixture screws on the front of the carb control the idle circuit which make the transition to the primary circuit if these are off the whole carb will act up if you have touched these already put them in all the way until they bottom out but don’t tighten you will damage the tips then pull them out two full turns that should give you a good starting point to adjust from the idle will probably come up while doing so so turn idle down as needed while doing this timing first get that set then move onto carb if need be and verify the plugs are right for the car and in good shape and more questions shoot me a dm.and sorry for such a long response lol
How did you mount the square bore carb to the spread bore intake?
20-22 degrees at 1100 RPM
20-22 degrees at 1100 RPM
Was the original Q-jet busted? If not, the money buying an E-brock could have been better spent getting a good carb rebuilder to rebuild the Q-jet (not the box store rebuilts). The Q-jet is a perfect carb for a 307, because it's a...… 307. 307s can run very well with a good Q-jet, and that's all you could expect. I still don't know what the idea is with the use of these 1405's on Olds engines.
Many have issues with Edelbrock carbs, especially on Olds V8's. Some have spent hours tuning them with no improvement. I bet the timing is still retarded, low compression Olds V8's like a lot of timing. Try 20 degrees at 1000 rpm and go from there. Check and see how many degrees the vacuum advance adds for timing, should be around 30 degrees, I would run it off manifold vacuum. The Canadian non CCC(computer controlled) cars had anywhere from 13 to 22 base timing for the 307, going by the under hood emissions decals. The low vacuum could be retarded timing. It is more likely a vacuum leak under that square bore carb. Your car won't be a power house but should be acceptable, especially with the earlier 307. A properly built non CCC Qjet from someone like Everyday Performance or a Street Demon carb tuned to your motor might be worth considering over the Edelbrock. Also your lock up torque converter will need a control of some type. Also a 3.42 or 3.73 gear with your 2004R trans will wake up the car a lot.
Then get a 1975 Q-jet. The 1405 would never be my first choice as a replacement on a 307.
You're running a stock non CCC that came off a Canadian 307? Is it a known good one? Was it installed properly? You got any plug wires crossed?
IMO, a Qjet is a way better choice than any Edelbrock but it should technically still run fine with the Edelbrock, so unless this carb is horribly out of tune I'd be looking at the distributor for your issues.
IMO, a Qjet is a way better choice than any Edelbrock but it should technically still run fine with the Edelbrock, so unless this carb is horribly out of tune I'd be looking at the distributor for your issues.
- Status
Similar threads
