Trying to work the bugs out of my 87 Formula...

Flooring it from a standing stop and flooring it when it's going below 30 or 40 MPH, the engine just doesn't seem to develop any power. If I back off the throttle just a little, it's like night and day, plenty of power. Happens the same whether the engine is hot or cold.

One thing I don't like is a previous owner disabled the choke. Basically disconnected the rod and bent where the rod goes on the choke shaft so the choke can't close.

No SES light, no codes...

New air filter, fuel filter, PCV filter, PCV valve.

Adjusted the air valve tension last night and it did seem to get better, but the symptoms still remain. Before adjustment, these symptoms happened whatever speed I'd floor it at, now it just seems to happen in 1st gear.

I'll be giving the carb a good workover with some carb cleaner this weekend. Will also be checking the timing and putting new plugs in. Hoping to get this problem solved so I can get to the track next week and basline this thing before I start modifying it. Will probably rebuild the carb over the winter.

Already have MSD cap, rotor, coil, and plug wires bought for it.

Airflow enhancements will be next (K&N filter, cold air induction, possibly a carb spacer)

After that it will be Hooker headers, and 3" exhaust all the way back.

Hoping to get ETs and MPH for each set of mods.

 

Make sure the secondary rods haven't fallen off their hanger and that they are both lifting out of their jets as the secondary air valve opens. Besides, stock secondary rods for an LG-4 are very wimpy. If they're stock they should be stamped CH. A switch to the more aggressive DR rods used in the L-69 HO 305 engine can make a very noticable improvement in WOT performance and throttle response.

Also make sure the vacuum break on the side of the carb is opening fully and with reasonable speed. It acts like a "shock absorber" so the secondary air valves don't slam open when you nail it (in conjunction with the air valve tension spring). When fully retracted it should allow the air valves to open just a tiny bit before it catches them. It should also go from fully retracted to fully extended in about 1 second or so, if it's stock. If it's taking a long long time for it to extend then replace it.

Last thing that could be happening is that the secondary enrichment tubes inside the carb have either gotten clogged or have fallen out. They act like an accelerator pump on the secondary bores of the carb. Really, you need to take the carb apart to check for this so do simple stuff first.

 

thanks... was hoping someone would respond before I left work (computer at home is dead...)

Gives me a list of things to check this weekend. Have the Haynes book on the Q-Jet and remember see all these parts in there, so I should be able to work it out.

Will probably go pick up a rebuild kit and extra gaskets in case I decide to tear the top of the carb off to check things.

 

Found the main problem, one of the secondary rods had come off the hanger...

So I fixed that, cleaned the carb out real good with carb cleaner, at which time I found out both the throttle shafts are leaking...

Still had somewhat of a bog, but I could floor it and make power from 2nd gear on up.

Did some tuning at a local office park with the idle air bleed. Big difference. Now it doesn't bog at all after the cars been warmed up. The car can now lay rubber in first gear.

 

Glad to hear it was something simple.