[WildBill79]

I have been chasing a slow crank issue when hot. When cold, it turns over quickly and fires right up. When hot, it will barely turn over and I have to wait 5-10 minutes before it will turn over enough to fire up. I installed the ford starter relay and have the same problem. I even installed header wrap on the driver side header and still have the same problem. What else can I try before spending the extra money on a mini starter?


Setup:
'72 Ventura with Pontiac 350
Headers (come very close to the starter on driver side)
New Battery in trunk. 800cca
New 2 gauge welding wire throughout
Grounds are going to the block and frame
Ford Starter relay
New stock replacement starter

[stellar]

Make sure battery is good, cables and connections are good at both ends of each cable, timing is on, starter is in good condition.

[67cruiser]

Put a good starter in and loose the replacemant starter is what i would do. I have same set-up Batt. in stock location. No issue,s. No need for a ground to frame.Yep headers are close to starter but i don,t run any header wrap at all again no issue,s.Todays high per. starters are so much better than the stock replacemants plus install a mini starter, only way to go.Summit Racing, a little over 125.00$ for a mini starter.

[Donovan]

Well unless you disable the solenoid on the starter it is still there and in use. You just have a redundant ford solenoid in the mix now.

A simpler and more elegant solution is put the stock wiring back in place(remove the remote solenoid) and install a ministarter. Why use a heavy stock starter when you've gone to all this trouble to move the 50lb battery to the trunk?

Also! is that leg of the hotwire going from the trunk protected with a fusible link or fuse? Or perhaps you put the ford solenoid in the trunk near the battery and have a separate battery charging circuit?

[screamingchief]

Originally Posted by WildBill79

Grounds are going to the block and frame

Are you running a seperate ground cable up to the block from the battery?

Or are you just short grounding cables from the battery to the frame in the rear,and from the frame to the block in the front??

If the later method,seriously consider the first method,as frames tend to be a somewhat poor ground path in many cases.

And often even 2ga. cable is marginal @ best for trunk mount battery set-ups,typically I would recomend 1/0 ga. cable as the bare minimum for best results,a simple voltage drop test will tell you if your current cable set-up is up to the task.

Originally Posted by WildBill79

Ford Starter relay

How is the ford solenoid currently wired to the ignition switch?

Wires that run from the ignition switch that used to run to the OE solenoid on the starter now wired to the ford solenoid?

And where is the ford solenoid actually mounted??

IME,the ford solenoid should be in the trunk,and then one should use that OE ignition switch wiring to trigger the low current side of a seperate 30/40 amp Bosch type relay in the trunk,and run the high current side of that relay to the "pull in" side of the ford solenoid,that way you create a much shorter path for the pull in side of the ford solenoid,the only downside to doing it this way is you must also rewire the alternator charging wire(s).

Food for thought.

Bret P.

[gtofreek]

A stock starter should turn it over fine.

Are you using the frame as a ground? In other words, does your ground cable from the battery go to the frame? Or all the way to the engine? I have seen this same issue when the battery and engine are ground to the frame instead of each other. The frame is not a good ground source, despite what others have gotten away with. When I did auto electrical, this was a common problem with trunk mounted batteries.

If it lugs hard when trying to start, your timing may be too far advanced.

[gtofreek]

Screamingchief gets it.

Also, the Ford relay only cures the hot start issue where you get no click at all. Nothing happens. Since it cranks, the Ford relay is doing it's job.

[WildBill79]

The positive wire from the battery is ran to a terminal on the core support. The battery ground is to the frame. Also on the core support I have a terminal for grounds which go to the engine block and from the block to the frame. Basically I have remote battery posts in the stock location, with the battery in the trunk.

The ford relay is mounted on the core support next to my battery terminals and i just extended the factory wiring slightly.

I still need to wire a fuse or circuit breaker on the positive side of the battery. What size is recommended?

Voltage drop test is something I can do. Thanks for mentioning it.

Electrically everything is working great until it gets hot, then it is only the starter that seems to have an issue.

[Craig Hendrickson]

There is a standard duty stock Pontiac starter and there is a heavy duty stock Pontiac starter. I had the same hot hard start problem with my 1979 TA W72 and replaced the std duty with HD and never had the problem again. The heavy duty one is a bit longer and has a copper spacer between the solenoid and the terminal coming out of the starter case that screws to the solenoid. That copper spacer indicates the longer length Heavy Duty starter. You can get either from virtually any parts store. You should not need a new mini-starter.

[Schurkey]

Originally Posted by WildBill79

Voltage drop test is something I can do.

With the battery in the trunk, one of your meter leads will need to be much longer. Ordinary primary wire will suffice.

Originally Posted by WildBill79

Electrically everything is working great until it gets hot, then it is only the starter that seems to have an issue.

If it's not a cable problem (and I think that's likely) then I suspect the field coils are overheating and have high resistance due to temperature. The field coils may be defective, and the heat-soak just puts them into a situation where they won't crank the engine properly.

Originally Posted by Craig Hendrickson

There is a standard duty stock Pontiac starter and there is a heavy duty stock Pontiac starter. I had the same hot hard start problem with my 1979 TA W72 and replaced the std duty with HD and never had the problem again. The heavy duty one is a bit longer and has a copper spacer between the solenoid and the terminal coming out of the starter case that screws to the solenoid. That copper spacer indicates the longer length Heavy Duty starter. You can get either from virtually any parts store. You should not need a new mini-starter.

Problem is that many starter motors use the longer case, but without the longer field coils or longer winding on the armature. In other words, they're externally similar to the high-torque starter motor, but without the beef inside where it counts. You won't know unless you pop the front cover and look inside.

[WildBill79]

Thanks Shurkey, I am going to attempt that test after work. Does the starter need to be in the car? It will be easier to access the terminals if I lower it to the ground, leaving it connected of course

[screamingchief]

Originally Posted by WildBill79

I still need to wire a fuse or circuit breaker on the positive side of the battery. What size is recommended?

Honestly,that's going to be problematic.

The initial amperage draw for the starter is typically waaayyy above what most fuses can handle.

So you hafta use the slow-blo type fuses (or circuit breakers),and even then it's going to need to be a big nasty one at that.

The best way to do this is to put the ford solenoid in the trunk like I mentioned earlier,with a seperate bosch relay to activate that,and that way the battery + cable is cold except when it's cranking.

To do that you have to add a jumper on the starter solenoid,and like I mentioned rewire-reconfigure the ignition switch/starter wiring and the charge/harness wiring somewhat.

And in the process of rewiring the charge/harness wiring,then you can fuse/CB the wiring that goes back to the stuff in the trunk,as the amperage for that stuff is much more manageable than it would be for the + battery lead to the starter itself.

There are tons & tons of articles about how to do it that ^^^^ way on the web,and it's been discussed here a bunch in the past as well,so the information is there for the taking.

One of the earlier proponents of that sorta set-up was MAD electrical.

Currently the way it's wired right now,there are lots of unnecessary connections that are just adding resistance to the whole "start" circuit,so the circuit needs to be simplified somewhat.

HTH

Bret P.

[screamingchief]

Originally Posted by WildBill79

Does the starter need to be in the car?

Not only does the starter need to be on the car,but you need to be doing the voltage drop test when the problem is actually happening (ie: engine hot and the starter "dragging").

The idea is to see what's going on with the voltage when the problem is actually happening.

I know that makes for a job that really sucks,but that's how diagnosing electrical problems go.

Bret P.

[Schurkey]

Originally Posted by WildBill79

Thanks Shurkey, I am going to attempt that test after work. Does the starter need to be in the car? It will be easier to access the terminals if I lower it to the ground, leaving it connected of course

Originally Posted by screamingchief

Not only does the starter need to be on the car,but you need to be doing the voltage drop test when the problem is actually happening (ie: engine hot and the starter "dragging").

The idea is to see what's going on with the voltage when the problem is actually happening.

I know that makes for a job that really sucks,but that's how diagnosing electrical problems go.

Bret P.

Yup, the starter has to be cranking the engine to get a valid result.

If you have a high-amperage current probe, it would be useful to discover how much amperage the starter motor was drawing, too.

[Craig Hendrickson]

Originally Posted by Schurkey

Problem is that many starter motors use the longer case, but without the longer field coils or longer winding on the armature. In other words, they're externally similar to the high-torque starter motor, but without the beef inside where it counts. You won't know unless you pop the front cover and look inside.

This must be true only for rebuilt starters. In any case, it's easy to pop the front cover and look inside as you suggest.

[gtofreek]

There is a sure fire way to tell the low torque starters with the solenoid extension from the old high torque starters without taking them apart. It's not supper easy to explain, so I will try to find both types and take pics to show the difference.

[67ramair4]

Here's a cheap fix; the shorter solenoid spring! P/N 1978281, even using the high torque starter, I had hot start issues. Installing the replacement spring cured it!!

[gtofreek]

The spring works in some cases, not all.

[jonmachota78]

Ive had new 800cca batteries that were junk. Last time i had this problem i pulled my newer 800cca battery out and for grins put in my 325cca deep cycle boat battery.... problem gone, it would crank it all day when hot. Not saying thats your problem but i'd make sure you have a quality high capasity battery in there before tearing the thing apart too far. Im done with cheap batteries.

[WildBill79]

I am going to perform the tests suggested. Also I uploaded a crude drawing of how I believe you guys are advising it should be wired. Let me know if it is correct. For safety I would like to eventually get it wired this way. I think I will also try a mini starter since they seem to be better all around anyway.