Hot starting problem

[68sportsatelliteragtop]

Hey Guys, I've had this problem for a while now and haven't been able to chase it down. I can hop in the car, my 67 Belv 383,10-1, 484 cam,and pump it 2 times and it will start after sitting in the garage for up to a week, much longer and I crank first then pump 2 times and it fires. Problem is after reaching temp and turning off then restarting after 15 min. up to 2-3 hours I have to crank and pump 4-5 times and hold 1/2 throttle to get it to fire. After starting no sign of black smoke, doesn't act like it is flooded.The problem started after I installed an MSD6AL and new NGK plugs w/ .050 gap.I removed the ballast resistor from the ignition with same result. If car sits long enough for temp gauge to go to 100 it will fire off w/ 2 pumps. I don't smell gas in the oil, any thoughts? Thanks for your input

 

[green1]

Crap ethanol.

 

[SirSixPack]

Any chance that your starter and ignition wires are now closer to your exhaust system?

 

[68sportsatelliteragtop]

Starter and ign wiring are routed as stock w/ MSD wiring added to engine harness. I mounted the MSD below the washer bottle on the pass. side fenderwell. I have considered moving it but did such a nice job on the wiring and really don't have a better spot in mind. The car has an A/C heater box that eats up a lot of the underdash area. Only other spot I can think of is in the glove box, but it won't get any air in there either.

 

[sicksatellite]

Vapour lock perhaps?

 

[plymouth67]

Edelbrock carb? I cant tell from the picture. If so they have a problem like that and I have had it happen with holleys also but its called heat soke its like vapor lock where the carb body gets hot enough to allow the gas to expand and drip out the needle and seat and into the motor when its warm leaving the float bowls almost empty and the motor full of gas but not so much that it acts flooded, but is hard to start. Run the motor get it up to temp and then shut it down pop the hood get by the carb and listen it may take a few minutes but you will hear what sounds like gas boiling. they make a heat plate to put under the carb to help with this. Keep us posted!

 

[Randy73]

Did you do anything else when you did the plugs and MSD box?

Chances are that you changed something you forgot, like idle, timing or fuel/air mixture.

 

[74sundance]

I would say that you need a phenolic carb spacer they are only about $20.00 and help stop heat transfer and fuel evaporation.

 

[68 Sport Satellite]

I had the same problem. It's almost definitely the fuel boiling. There's a great article on this somewhere on here that I came across last year but now I can't find it. To remedy my problem I did a couple of things - added a 1" thick phenolic plastic spacer between carb and manifold, replaced my 2 port fuel filter with a 3 port filter (ran the 3rd port which is a vapor return line, back to the fuel tank), and I installed a fuel pressure regulator in-line between the fuel pump and the carb. After all was said and done, I think what likely fixed it was the fuel pressure regulator. The other forum topic I came across was saying that ideal fuel pressure should be something like 3.5 - 4 psi or there's too much fuel in the carb and it will boil when you shut the car down. Mine was reading 8psi. Once I did all this the problem was solved.

Only thing is now the problem resurfaced last week. I had the car into the shop to install some suspension and steering parts and I'm wondering some of the fuel lines are too close to hot surfaces, causing fuel boiling. It's very frustrating. The other new thing I did that may or may not be related to the problem resurfacing is I just installed new plugs. The old plugs were gapped at .035 and I gapped these at .042 hoping for better performance. If I squirt some Gunk engine starter into the carb, the car fires right up. What do you guys think?

 

[68sportsatelliteragtop]

Unless you are running some type of HEI, MSD or equal, I would think your spark gap is too much. As far as the fuel boiling issue, I don't follow how the car will start as normal if it sits for a couple hours. Seems to me if it is boilling out of the bowls it would still require additional cranking whether it sits 10 mins or 2 hours or 2 days to fill the bowls back up. After the motor cools, it fires right up , 2 pumps and bingo, every time.

 

[68 Sport Satellite]

Unless you are running some type of HEI, MSD or equal, I would think your spark gap is too much. As far as the fuel boiling issue, I don't follow how the car will start as normal if it sits for a couple hours. Seems to me if it is boilling out of the bowls it would still require additional cranking whether it sits 10 mins or 2 hours or 2 days to fill the bowls back up. After the motor cools, it fires right up , 2 pumps and bingo, every time.

Thanks very much for the quick feedback on the spark gap - in regards to that, my research on stock gap says for a 360 motor like I have, it should be .035 running points.

I have the Mopar silver box electronic ignition and I've read several places that recommend bumping the gap up to .040 minimum up to a max of .045, so I gapped them at .042. Anybody else think with my setup that .042 is too much and if so, should I put it back to .040 or .035? Can too much gap affect a hot start? The # 5 and # 7 wires are also very close to the headers - can this cause a hot start issue?

As for the fuel boiling issue - I found in my files where I found that article. It was in the Oct, 09 issue of Mopar Action magazine in the tech topic section. The author says the issue is not the fuel boiling completely out of the carb, but rather that vaporized fuel can't be pumped or metered and today's high RVP gas (relative vapor point) exacerbates the problem.

I went outside in the rain this morning and gave everthing a quick check again - the fuel filter is between the carb and pump, no gas smell in the oil dipstick, all fuel lines are at least 4-6" away from all heat sources except the line from the pump to the in-line fuel pressure regulator is resting against the top of the head and the intake (but these don't seem that hot to the touch and I'm not sure how to clear that contact), it fired right up this morning after a few pedal pumps and closing the manual choke on my Eddy carb so fuel is getting to the carb and I have my fuel pressure set to 4 psi at idle. But then after shutting down and trying to fire it back up, whether pumping or not pumping the gas prior to turning the key, the motor just cranks and cranks and it won't fire.

By the way, I didn't mean to hijack this thread - I have a similar issue and if the original poster hasn't got his car fixed, hopefully new info provided for my problem will lead to a solution for both of us...

 

[68 Sport Satellite]

68 SS ragtop - ha ha - you WERE the original poster - my bad. Yeah, I have the same exact problem. If it cools then 2 pumps, 2 cranks and it fires right up. What's aggravating is that after I implemented my 3 part remedy a few months ago, I test started it hot 3 times in a row with 1-2 minute rest intervals in between starts on two different days and it started fine every time. Then in the last month I've had a few things done to the car by mechanics and the problem started. The work was nothing related to fuel or ignition and I don't see anything different, so I'm not sure what it could be.

The only thing really different is that my plug gap is now .042 and it's been raining a lot outside, whereas before it was sunny and warm. Can moisture in the air affect hot starting? I know on a cold start sometimes moisture can get trapped in the dist. cap and interfere with spark and a squirt of WD-40 inside the cap displaces the moisture and the car will fire, but I never heard of such a thing for a hot start issue when it starts fine cold in the same wet conditions.

 

[68 Sport Satellite]

could it be that since we both started having our issue recently related to installing new plugs - mine gapped at .042 and his at .050, that with those gaps the plugs are what needs cooling and not the fuel? Will a hot plug tip that's gapped too much exhibit this issue?

 

[68 Sport Satellite]

I think one or both of us should regap our plugs down to .035 and see if the problem goes away, then bump the gap up little by little to see what works. My stupid # 7 plug is impossible to remove without unbolting the headers though. I wonder is I change 7 of the 8 plugs with a regap if it will matter.

 

[68sportsatelliteragtop]

Are you running an MSD?

 

[cj's mopar]

This maybe a long shot but how did you wire the power feed to the MSD?
does it have spark when the engine is hot? Do you have the key in the crank position?
some times people wire the msd to the key on position. both the crank and key on positions it should fire the coil . i have had it happen when the car catches cold it fires when releaseing the key from the start positon and not start when hot . it was a bad ignition switch .

 

[68sportsatelliteragtop]

When I first got my 68 satellite it had been monkeyed with and was wired backwards on the firewall, and like you said you could crank that sucker all day then let go of the key and it would fire sometimes and start. I straightend that out and now it starts like it is supposed to.This problem is with my Belvedere. Never had a hot start problem until I installed the MSD. It will start but you have to crank it alot more than when it is cold. Doesn't want to fire when you stop cranking though. MSD is in the engine compartment under the washer bottle. I probably won't get a chance to drive it soon as they are calling for snow tonight and have already pretreated the f'ing roads. If we get the snow they will sugarcoat the roads with salt and I won't be out until after the rain does its thing!

 

[68 Sport Satellite]

I'm running the Mopar silver box electronic ignition.

 

[68 Sport Satellite]

Well, I had my mechanic wrap the passenger side header all the way from the collector up to the head, which is the side the fuel pump and lines are on, then also on the driver's side from the collector up past the starter (didn't want to have to disconnect the steering linkage for a complete wrap on that side). (I'm a lazy bastard these days and with no garage and the inclimate weather, I had my mechanic do it while I was at work so I could just Get 'Er Done!) Then I bought some hose insulation sleeve and placed that over the fuel lines in the engine bay and I also added spark plug wire insulation sleeves as well. All of this in an effort to minimize heat to any lines carrying fuel as well as insulate some header heat from my newly rebuilt starter. So far, so good. I did 3 hot starts on the car yesterday and it fired right up. I'll let it sit a few days and drive it 3 or 4 times to work back and forth next week and then report on the results. The header wrap doesn't look pretty, but it works. Sometime down the road if I ever get the money together to drop a 440 in there to replace the 360 or stroke that 360 to a 406, then I'll spring for some ceramic coated headers, which I think will insulate the heat without any wrap am I correct? I already had the 1" phenolic carb spacer and vapor return line from the fuel filter, so I think I've done all I can do. I hope it doesn't give me any more trouble!

 

[68 Sport Satellite]

I forgot to mention that my mechanic also thought one reason my problem resurfaced when before I thought I had it fixed is the winter fuel mix from the gas stations. It may have made it more prone to the fuel boiling / vapor lock issue. I insulated everything l could from the heat, installed new wires, plugs, did timing, tuned the carb, and now she's starts and runs like a champ. I'll keep you posted in the coming weeks.