mpb74

i have an old set of heads on my 350. my compression is over 10.5 to 1.
the engine is running rich. if i were to open the gap on the plug wider,(currently gapped at 35) could this help?

i havent pulled the plugs out yet to see how their burning. i just heard that the gap being too small will cause an engine with high compression to run rich. i wasnt aware of the gap issue until yesterday. do any of you have any experience with this subject?

Theking

iTrader: (1)

What else have you done to the engine. Original gap is 035" (if you got an aftermarket ignition system that puts out more spark you prolly could try 045"..
Whats your fuelpressure ? And when did you serve the ignition system last time (sparkplugs/wires,dist cap, rotor)

Take them out and look at the color of them. and get back here.

mpb74

everything is farely new, maybe 2000 miles on it. i do have the accel super coil.

mpb74

i pulled the plugs out last night. they were all covered with black soot.
the gap ranged from 32 to 35. i regapped them to 45 and drove it up the street. i didn't have a chance to pull them back out but the car seemed to run a little leaner

lukn4trbl

Plug gap has nothing to do with air/fuel ratio.

Unless you experiencing misfire from improper gap, the ratio will not change.

There is an issue with the fuel system.

Theking

iTrader: (1)

Yeah, have your fuelpressure checked, and check so it holds pressure good after shutting down the engine, maybe you have an leaky injector or bad FPR...
Its an fuelling problem, not sparkrelated, you getting flooded and the low gap 035 dosent make a clean burn, therefore an sooty plug...
You have to give it less fuel and gap it down to 035 again and then you will see a power gain and right A/F ratio..

mpb74

what is considered a good fuel pressure for a modest 350?
i have a stock mechanical fuel pump.

if my car had a fuel pump in the tank, would i be getting gas to the carb with a mechanical pump? i'm not sure where the original pump was mounted. i'm assuming it was mounted on the side of the block since the car came with a 305 carb from the factory.

naf

iTrader: (7)

You've got a carbed motor. He was assuming fuel injected.

If you're running a mechanical pump on the block look elsewhere.

What carburetor are you using? What type of distributor?

mpb74

a small holley 600 carb.
my distributor is stock with a accell super coil hei.

lukn4trbl

8 PSI max at the fuel inlet.

Have you set the float level? What size power valve in the primary?

Do you see fuel pooling on the base of the intake plenum?

naf

iTrader: (7)

The stock distributor is computer controlled (unless you've got an export model). You can tell by the lack of a vacuum advance can on the side. Running a computer controlled distributor with the computer no longer controlling it is part (could be all) of your problem. Your timing AND timing advance is essentially stuck in limp home mode. Retarded timing will result in incomplete fuel burn.

Ignition issues should be fixed before starting carburetor adjustments. Replace the stocker with a standard mechanical and vacuum advance HEI and set the base timing correctly before tuning your carb.

This doesn't mean you may not have other tuning issues with the carb swap, float level, etc. but you need to fix the ignition first.

mpb74

my bad, when i said stock, i meant that it wasnt a high performance distrbutor. when i purchased it, i bought a distributor for a 1970 camaro 350.

mpb74

i had someone else set the carb, because i dont know anything about float levels. the power valve is what ever holley installs from their fact. i bolted it on out of the box. i haven't seen any fuel pooling but i will check.

thanks for the fuel pressure inlet. i didnt think too much about that because so many older cars run mechanical fuel pumps with no problems, i thought i would be able to do the same..

dKillaCamaro

Replace the stocker with a standard mechanical and vacuum advance HEI and set the base timing correctly before tuning your carb.


Can you tell me more about this swop and what all you need and how ta make it work Thanx

mpb74

ok, i regapped the plugs the other night to 45. last night i drove the car around and blew the soot off the plugs. after getting it home and letting it cool down, i pulled the #1 out and it was starting to turn lite grey.

mpb74

yeah, what do you want to know.
i can start with the basics.
1986 iroc-z, it came stock with a carb 305. it didn't have an engine when i got it. i had a 350 reworked, stuck on an old set of heads(and i hat'em) my heads are old and they have been shaved. that makes my compression go way up and my engine rattles like a spark knock because i can't afford 100 octaine

dKillaCamaro

was wonderin about the distributor swop
how to make a computer controlled distributor Mechanical(vac adv.)
also can you still use your computer to be smog legal?

mpb74

i'm not sure about that.my computor isn't hooked up. one of these other guys will be able to answer that one for you, but you may have to start a new thread. i would like to know how to tell if my torque converter is locked.

dKillaCamaro

KThanx new thread

locked up
think u can feel it in 4th if its workin

alsothink on autos when you are on it a lil thew the gears nd when you get ta fourth gear and let off ta cruse on tha gas a lil thow still acellin you can feel tha torque converter lock or un lock not sure but feels almost like 5th gear

naf

iTrader: (7)

If you've removed the ccc-qjet your converter is not locking. You can install a vacuum switch that will lock it, or buy one of the kits from Summit, etc. A search here should turn up the parts needed to do it yourself.

You can test lock up by cruising at highway speed. Keep your right foot on the throttle at constant speed. Tap the brakes gently with your left foot. The brake switch will disengage the lock up and you should notice an rpm flare of 100-200 rpms.

You can't convert the computer controlled dist to vac advance. The ecm will also NOT allow you to mix and match ccc-qjet and mech dist, or vice versa. The computer relies on signals from both to control the mixture.