# Starting Problems While Hot



## Sixty7GTO (May 4, 2017)

Good evening,
I have a friend that has a starting problem when the engine is at normal temp.
When it's cold there have been no problems even after 4 different starters, but when hot after a drive each of the starters has turned the motor over very slow as if the timing is way too far advanced. The original starter after being rebuilt, a factory rebuilt High torque starter, and two different Powermaster High Torque starters all act the same way. Battery cables are new, ignition switch has been changed with an Ames one, the battery is new and has been load-tested, the centrifugal advance plate has been check to see if it was sticking. The vacuum advance has been disconnected and locked down, the base timing has been checked many times by different people. it is currently set at 8*. Today I checked to see if the number of the Powermaster Starter was the correct one. There was a discrepancy in the part number of the one being used. It was checked against some different on-line vendors. One vender says The PM9610 is the correct one and the other vender says it is not and the application should be using a PM9410 (These are Powermaster Part numbers) One vendor says the MS9610 is for an Oldsmobile/Pontiac and the MS9410 is for strictly Pontiac. OK, you say what is the application ??
It's a 1967 GTO with a 72 Grandville 455 Motor, Total rebuilt. It has aluminum heads, a medium cam, forged pistons running about 10.2 to 1 compression, Eagle crank, and rods, Edelbrock intake with a 750cfm Edelbrock carburetor. It has had two different distributors in it (same results)
It is an 3-speed T400 with His and Her shifter with 3.55 in the diff.
Today he tried putting a heat mat around the starter to combat the heat soak issue. He also has Ram-Air manifolds and there isn't a lot of clearance between the starter, block, and manifolds. The manifolds were coated but the coating is starting to wear off.
I have done a search on this forum and the only thing we haven't addressed is upgrading the battery cables to #2, They are a #4 at the present. I'm saying the solenoid gets heat-soaked. I told my friend to buy a Powermaster that you can clock the solenoid as far away as he can from the Ram-Air Manifolds. But what if this is an unsolvable problem, there has to be a solution but I'm out of ideas. Sorry, I rambled on here but I wanted you guys to know the whole sorry.


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## PontiacJim (Dec 29, 2012)

I would begin by adding the heavier battery cables. Less voltage is supplied when they become hot.

It could be heat soak of the solenoid, but I would go cables first. On some mini-starters you can clock the solenoid down away from the exhaust manifolds which can help. But, that may mean adjusting your battery cable length. The RobbMc starter seems to be a good choice for mini starters.

High compression can have an effect on the speed the engine cranks over when hot.

I like to gap plugs at .035" as it takes less energy to fire them. This may be of help.

Timing is the next thing that can be problematic. Don't know why you have the vacuum advance locked out? 8 degrees probably is not enough with a bigger cam. I'd have it up around 12 degrees, maybe more. With that, you then need to know what your total timing is and at what RPM. Too much and you will get pinging/detonation and damage the engine. Often, with the initial timing and vacuum advance connected to a manifold source, timing will be around 19-21 degrees at idle (650-750 RPM). Then you adjust your timing curve/full advance numbers.

You could also have a fuel leak where the fuel could be dripping into the intake and causing a rich condition that can produce hard cranking until the excess fuel is cleared out. Easy enough to detect by smell or possibly white fumes (gas boiling off) rising from inside the carb with the air cleaner off.

It could be possible that the cam timing is off. Was it installed using a degree wheel and dialed in per cam manufacturers specs, along with the piston at top dead center? If it was not installed correctly, it could change the opening closing events and build additional cylinder pressure. Many aftermarket cams are ground on a 110 LSA which builds cylinder pressure at the lower/cranking RPM's, so you may have 10.2 compression but have a higher cranking compression nearer 11 to 1. That is the difference between static and dynamic compression. Wider LSA cams will bleed off cylinder pressure at lower/cranking RPM's.


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## Sixty7GTO (May 4, 2017)

Thanks, Jim
When I first looked at the car, The base timing was up around10-12 degrees and my friend was having some pinging and was jumping around a little. I pulled a little timing out and that's why it is at 8* now. The vacuum was disconnected because I just wanted it out of the equation for now. Ray, my friend had put an adjustable vacuum diagram on it because someone suggested it. I asked him for the one that came off and he said he threw it out.
No gas odor and when it does start there's no black smoke. No white vapors coming up threw the throttle bores. Open up the throttle plates and look down inside, no pools of gas.
I asked about the cam installation and the spec's but Ray said he would have to look for the card, but it is one of the things I was wondering myself. I just have to wait for ray to find the cam card. I said it probably has a 272-280 duration cam, it just has a little lope to the idle. The timing light Ray had didn't have the dial on the back. Mine does so that's something for another day.
Ray works at Electric Boat in the welding dept, so I told him to pick-up some flexible welding cable and he can make some heavy-duty battery cables.
I also read on this site someone used the FORD solenoid "fix" to solve the problem. What do you think of that?
I'll also have him look at the RobbMac Starters.
Thanks, 
Dave


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## Lemans guy (Oct 14, 2014)

Yes I use RobbMc starter on my 461. You can clock the solenoid 360. I put it right at the bottom down in the air stream.

agree with bigger cables. Smaller cables give too much resistance when hot and that may be what you have.

Get some DEI heat shielding from summit or JEGS. And put it on those cables that are near any hot manifolds. DEI even has Velcro shielding you can put on cables without taking them off.


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## Old Man Taylor (May 9, 2011)

Hopefully you don't need it, but the Ford solenoid fix runs the battery power through a relay. The start switch energizes the relay, hence only the power wire is required at the starter. The problem is where to put the solenoid. My racecar has the battery in the trunk. The "Ford" solenoid is mounted right next to the battery. A long wire has to go up to the starter anyway, so it was cleaner putting the solenoid in the rear. Most people put the relay on the firewall with the stock battery location.


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## PontiacJim (Dec 29, 2012)

Sixty7GTO said:


> Thanks, Jim
> When I first looked at the car, The base timing was up around10-12 degrees and my friend was having some pinging and was jumping around a little. I pulled a little timing out and that's why it is at 8* now. The vacuum was disconnected because I just wanted it out of the equation for now. Ray, my friend had put an adjustable vacuum diagram on it because someone suggested it. I asked him for the one that came off and he said he threw it out.
> No gas odor and when it does start there's no black smoke. No white vapors coming up threw the throttle bores. Open up the throttle plates and look down inside, no pools of gas.
> I asked about the cam installation and the spec's but Ray said he would have to look for the card, but it is one of the things I was wondering myself. I just have to wait for ray to find the cam card. I said it probably has a 272-280 duration cam, it just has a little lope to the idle. The timing light Ray had didn't have the dial on the back. Mine does so that's something for another day.
> ...


OK, a number of variables. I would first go with a length of "midnight auto" EB welding cables. I worked at EB in Groton as a painter/cleaner on the Ohio class subs just before they went out on strike in about 1987.

Did the engine just start running like this? Has it been running/starting good and one day this hard start problem began?

I have never had/used aluminum heads but it is said you can get around 10.5 compression, but have to use premium 93 gas. Others on the forum use them and may be able to chime in on this one. I think the initial should be higher. If the engine still has the original harmonic balancer, it is possible that age has gotten to it and the rubber bond that holds the outer inertia ring has deteriorated and the outer ring has slipped and you are not getting a true reading of the timing. It may read 8 but really be 15 - as an example. So you may want to verify using a TDC piston stop that you can buy and insert into the spark plug and check that the balancer is reading correctly.

The timing from that point on sounds like you know what you are doing, so make your checks and see what you have.

Maybe pull a valve cover and check to make sure nothing has loosened up. With the aluminum heads I am assuming you have to use polylocks IF you are using a flat tappet cam and not a roller cam. If they use the nylock or crimp style rocker arm nuts it is possible that they can back off and affect timing at the valve. Not much help here if you are using a roller cam as I have not had one nor set one up.

How are engine temps? Is the engine running hot? Don't trust the temp gauges. I would verify using the hand held laser temp gun and make sure your temps are good by shooting the upper/lower radiator hoses, radiator top/bottom/sides, and water crossover at the T-stat.

It may also be the cam specs. The guys running the higher compression, even with aluminum heads, like bigger duration numbers and a wider LSA, much like the Ram Air IV cam. The shorter duration and possibly tighter LSA may be suspect, but shouldn't be if the engine has been running good all along with some miles on it and now it is doing this.

I am not a fan of the Ford solenoid. Only reason is that it is very easy to steal your car if you do not have a means to lock the hood, steering wheel lock, or have some kind of hidden power shut-off switch. I can steal that car with a jumper wire to the coil and a pair of pliers (or 2 long screw drivers) to touch each battery post lug simultaneously to bridge the power from one post to the other and crank the engine over and fire it up. So the solenoid may be a great answer for some, and can be made for use as a remote means to crank the engine when working on it under the hood, but you need a means to protect the car from an easy theft should you go that route.

Keep us updated.


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## Sixty7GTO (May 4, 2017)

hello Jim,
The first thing, I'm going to fix is the hot starting issue. I truly believe his starter or solenoid had a heat soak issue. As I said it starts fine when it's cold. When up to temp not so good, it can just barley turnover. Most of the time he has to let it cool down. He came over to the house the other night and we talked. I gave him my amp meter starter tester. I told him what to do to see what the starter was drawing for amps cold and hot. The next day he held the meter on the cable, cold and then Hot while his wife turned the key. I talked to him that night and he told me the reading. 195-205 amps cold, and well over 400 amps hot. He's ordered a new starter. I told him to order the RobbMc as you suggested. I haven't talked to him since. maybe this weekend, He had put a Mini starter HD in there because he was having the starting problem. The problem I think he wasn't able to clock the solenoid to get it away from the ram-air manifolds, hence the heat cooked the solenoid and/or the starter field windings. I guess all starters are not created equal as some people tell you they are. One of the selling points on the RobbMc starter is the solenoid is adjustable 360*. I have intentions of checking out the other items you suggested. TDC, The pointer, Harmonic, Distributor and it's play. I didn't pull a valve cover to check the rockers and I'm thinking about putting a degree wheel on it while the valve cover is off and see how the cam is installed. Bob did mention that the builder either advance or retarded the cam but he isn't sure or if he installed it straight-up. It's hard to do what I think should be done, I haven't gained his trust yet. This is his baby and he doesn't want me playing with it. So I'll let him borrow the tools and tell him what and how to do it. I'll be there maybe just to help if he goes down the wrong path. Ok, Until next time. Thanks for your words of wisdom.


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