Hard starting. Need Help!

[Truckstr]

Hello all! I've got a problem with the 350 engine in my '67 truck cranking and cranking before it "catches" - but only AFTER the first time it's started cold. When cold it starts right up.

It's an auto equipped model and has headers, open element air cleaner and HEI. The choke seems to be working well.

So far, I've carefully set the idle (~800 RPM)

...and idle mixture screws (highest vacuum and RPM)

...and set the timing at about 10 degrees BTDC (it has HEI).

I checked the plugs and they look good. I put a new Summit HEI cap/rotor/coil kit in it, and still no help.

When I replaced the cap and rotor, I noticed that the weights on the mechanical advance were worn out. Apparently, the mechanical advance is virtually non-functional.

What have I left out? What's causing this thing to be so hard to start?

Any help would be greatly appreciated.

Thanks in advance,
Jeff

[boilrman]

sounds like you are getting a heat transfer to the starter from the headers. Put a heat shield on the starter and I bet your problem is solved. You can get the heat shield at any parts store for just a few bucks.

[Truckstr]

I don't think that's it - but thanks anyway. The speed of the starter isn't any slower at all. It just takes longer to start.

Could it be that the mechanical advance being "out-of-whack" has caused this problem?

Since the mechanical advance weights are loose on their pivots then they are essentially advancing the ignition - even at idle.

But... the other side of the proverbial coin is that if this were the case, then when I set the initial timing at idle, the portion of the timing provided by the mechanical advance was compensated for - wasn't it?

Maybe I'm just making this more complicated than it is.

Help!

[Truckstr]

bttt

[skyhawk1]

My suburban does the same thing. It's like the gas runs out of the carb and it has to pump it back up to it. I thought I may have a hole in the gas line, replaced all the fuel lines and it still does the same thing. Somebody out there has got to know what the problem is. HELP!!!

[Truckstr]

Well, now my truck does have a Q-jet. Does yours? They are known for having the lead plugs at the bottom of the jet wells leak. Most times a rebuild kit will come with a little foam piece that is used to hold an epoxy patch in place under those wells between the main body and throttle plate body. That's probably what's happening with yours, skyhawk1 - if it has time to leak down.

My '72 had that problem and I fixed that, but the symptoms were almost exactly opposite. It would require lots of cranking when cold and would start right back up if not allowed to sit for a long time.

If you decide that the carb is leaking gas, don't just ignore it. If allowed to continue the engine could suffer damage from the oil film on the cylinder walls being washed off by the oil. Yep, that means bare metal to metal contact on start-up. Un-good!

Hope that helps.

Jeff

[skyhawk1]

I have a fairly new Edelbrock 600 on my Suburban.

[Truckstr]

Well, maybe my diatribe will help somebody LOL.

Man, I hope somebody comes to our rescue. It's kind of embarrassing driving a fairly nice looking truck (no show truck here). Then, when ya cut it off when getting gas or something, the thing has to crank and crank to start.

[mikep]

I recently pulled the edelbrock my truck just because of that problem. I park on a hill and the gas was somehow draining out of the bowl at night. It took a long time to start in the morning. I tried this with different vehicles and different edelbrock carbs and every one did the same thing . I pulled the tops off the carbs and they empty on several occasions and this is with different carbs in different vehicles. When I park on the street in front of my house or in my garage where its level I have no problem but in my sloped driveway the edelbrocks drain every time. I have a holley on there now. It starts up in one revolution every time.

try pulling the top off the carb after it has been sitting a while. I'll bet you anything the fuel bowl is empty.

[meathead95]

mikep my edelbrock 600 does the same thing on level ground it starts right up and on even the smallest slope the it drains

[mikep]

Lets try to think this out then. What happens when vacuum drops? The needles go up and you get more gas through the jets. When you are stopped with the motor not running the needles are retracted and the jets are in their fully open mode. Now why would the gas drain through the jets to the boosters when its on a hill. The gas has to go through the boosters right. Theres no other way out unless it sloshes out over the top of the bowl and if it did that the bowl wouldnt be empty. It would be full.

There were mornings I'd go out to my truck and it would reek of gas . I thought I had a gas tank leak. Since I installed the holley it doesnt smell like gas in the morning and it fires right up. The problem only happened when I was parked facing up the hill but it happened every time .

[Johns70]

mikep, with the eldelbrock carb that is notorios, its a cheap fix, you need the off road needles and seats,the regular ones are solid and the off road ones are spring loaded needles.they even say in the owners manual this is the case,the parts store carries these seperate. i don't remember the price but i think they were around 15, for me it was just as cheap to buy a regular carter afb rebuild kit to get them,they come with both styles in the kit.

skyhawk1, what about your fuel pump the check valve will stick somtimes and the fuel will drain back threw the pump when sitting.that or to much fuel pressure blownin the seats open when parked,and dribbling fuel down the carb overnight.

truckstr, i would start with your dist. and the messed up mechanical advance,fix that first i bet it will cure the problem.

[Truckstr]

Johns70, thanks, will do. I talked to a fellow gearhead at work today about a possible replacement HEI distributor he thinks he has in his garage. The module, pickup, cap, rotor and coil are all new or nearly so on mine, so I'll just transfer 'em over if his is better.

I ordered a Crane adjustable vacuum advance cannister from Summit today. It comes with a spring kit but no new weights. Advance Auto Parts has a weight kit that has plastic bushings. It's only money, right? LOL

It always seems like there's something else on these old trucks, but I still prefer 'em.

Piston, over on the Engine board, seemed to think that the problem with my hard starting might be the choke not openning fully or the float level set too high. Seems reasonable, and I can check the choke easily enough, but I sure hate to tear into that carb to fool with the float level. Oh well.

Thanks,
Jeff

[mikep]

If the choke was set too tight you'd start easily but you'd have a long wait until it dropped off fast idle . If the float level was too hi you'd stall when doing sudden stops. Its really easy to set the float level on them. Pull off the caps over the metering rods and pull them out . Take off all the screws on top, knock out the roll pin that holds the accelerator pump linkage, pull off the top , turn it over . Use a 7/16 drill bit as a gage and measure from the gasket surface to the end of the float. Bend it if you have to. . Put it all back together. Takes 10 minutes. AFB's are pretty forgiving about float level compared to holleys but you'll know if its too high as you'll stall into sudden braking when the fuel sloshes into the throttle bores and you flood it . Ive had them set as high as 5/16" in a 12 second cougar I used to have. Small fuel bowl in them and sometimes you need at a higher level to prevent fuel starvation. They dont like hi fuel pressure either but that wont matter when you are trying to start after sitting a while. I still think you'll fing your fuel bowl empty after it has set a while.

[pierce]

I have the exact problem, starts right up when cold then takes forever after that. In my case, it's the carb. I have 2 same Edelbrocks carbs that I've switched between trucks and found it to be the carb in each case. I've adjusted the float and the auto choke is OK because the other carb worked fine with same set up. Thinking of a carb rebuild kit but it runs fine once started. Won't be long before I wear the starter out.

[pierce]

Oh yea...and both the edelbrocks are the new Q-Jet replacements Model # 1901 or 1910

[okietruck]

No one had mentioned fuel percolation, where the fuel vaporizes when carb is hot. This usually only happens during extremely hot weather, but I suppose it could happen anytime. It would only happen on a hot engine. Try a thicker base gasket to reduce heat transfer from the intake.