• When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.

Slow crank when hot ? '71 GTX

gary h

gary h

Well-Known Member
Local time
7:35 AM
Joined
Aug 30, 2015
Messages
680
Reaction score
597
Location
USA
I had this issue today: I drove about 4 miles shut off car for about 30 seconds ,went to start it and 440 wouldn't crank enough to start.Seems like timing was way off,(which it isn't).Waited a few minutes and it started. It was hot day about 90 out.Car was running cool and no vapor lock. I have the Big original HP exhaust manifolds. Any thoughts ? Thanks
 
Wiring at the starter heat soaking. If you have headers you need to wrap or shield the header near the starter wiring/connection . Also check that the grounds are clean and tight.
 
mine did the exact same thing yesterday. just remember not to give it gas or you will flood it. as mentioned it's heat soak in the starter and wiring . I am going to try a mini starter and wrap my headers
 
Take these guys advice. If it started right up after the car completely cooled down, the it's almost for sure the starter getting hot (I'd check grounds though too). I've had this problem myself and it's normally an issue with headers, but could happen with stock manifolds too. Insulation around the starter and/or exhaust pipes in that are would help + a mini starter would help too. Increased heat = increased electrical resistance
 
As noted, heat soak or bad cable connection / ground. Address both possibilities.
 
My cable from the relay to the starter(the fat one) was bad in the inside....how I don't know. I put a new one in and it is fine......go figure.
 
Something to think about, original battery cables and ground wires were of marginal size at best. I’d recommend cables no smaller than 2 gauge. Also, if you are using aluminum heads or intake manifold, I suggest grounding directly to the block. On a big block there are threaded lugs on the left front of the block, 7/16 I believe. I connect the ground cable from the battery to one of those and run a same size cable to the frame. I have the stock ground cable to the firewall, mainly just for looks. You might think that it’s major overkill, but my 10:1 stroker big block spins over no matter how hot it is. Also using a Denso mini starter, the permanent magnets don’t heat soak like field coils will.
 
just a thought for everyone go to your hose dealership and get a piece of 1 inch fire hose run all cables thru it to the starter. the fire hose will not melt and will reduce heat sink to all cables going to the starter. also do what prnd321 said i agree with bigger is better. i have had to use this method on heavy equipment for the same reason. it works well. again just a thought
 
MoparLeo said:
Wiring at the starter heat soaking. If you have headers you need to wrap or shield the header near the starter wiring/connection . Also check that the grounds are clean and tight.
Click to expand...
Hey he said original manifolds. Wrap header??? People need to learn to read and its not just you.
 
You can also delay the ignition till the engine is turning. It puts less stress on the starter.
 
thanks next time i will put on my glasses.
 
Ok I did not see about the manifolds, but it doesn't change the diagnosis or the recommended preventative measures. Headers, manifolds, whatever, Heat is the common denominator. Even stock manifolds used heat shields for spark plug wires and other components.
 
Are you using a repop positive cable to the battery? I had one, brand new out of the wrap, and the cable was not attached to the clamp well at all and caused a slow start and melty cable. Give yours a tug and make sure it is crimped good. You can also check for high temp on the cable itself which indicates high resistance in the connection.
 
If its heating that much in 4 miles that its hard to start. Runnig cool and no vapor lock I doubt very much heat shields are the answer. Unless that 4 miles was at 4 mph. Really unlikly for heat soak to set in in less that 10 minutes.
 
Thanks Everyone for the Ideas. This is what I am going to do : Insulate the starter cables and Look for a heat shield next month at Carlisle. I want to hear more about the Mini starter Like what brand is best? New or Rebuilt? Is there just one mini starter that fits ? And will my car sound like a "Rice Burner" when starting ?
 
are you sure its the starter? Whenever this happens to me it turns out to be a flooded carb from heat soak. Pedal to the floor to clear the flooding, key on and it starts. Just remember to let off the gas immediately.
 
SlinktRR said:
are you sure its the starter?
Click to expand...
Yes ,The car would crank wicked slow, barely turning over,not fast enough to start. I have had the hot fuel problem with my other Mopars and I really don't have that problem anymore since I started using No Ethanol fuel for several years now.
 
mopar 3 B said:
If its heating that much in 4 miles that its hard to start. Runnig cool and no vapor lock I doubt very much heat shields are the answer. Unless that 4 miles was at 4 mph. Really unlikly for heat soak to set in in less that 10 minutes.
Click to expand...
I should have been more specific,it was about 4 miles since last I started it.I was running errands around town.So my car did a total of 12 miles before the issue happened. With about three start ups total. While I ran in the stores.
 
Would still try pulling the coil wire next time it happens just to see if the starter turns faster.
Will also purge the hot air out of the intake and cylinders.
 
same symptoms here, I thought I had to change my stock starter because of heat from the headers. it would crank over really slow when hot after a 5-10 minute shutdown (convenience store) like the battery was dead. pedal to floor, starts every time. 10 years later, still using the same starter.
 
You must log in or register to reply here.

Similar threads

65PlymSatellite
65 satellite killing coils.
2 3 4
Replies
72
Views
4K
Bee1971
Bee1971
79B100
318 Crank No Start
Replies
16
Views
1K
79B100
79B100
E
Engine runs hot in slow traffic
2
Replies
22
Views
2K
1KoolBee
1KoolBee
1970charger440
dodge charger falls and stalls slightly when cold. Won't rund when hot.
2
Replies
20
Views
657
Wietse
Wietse
eldubb440
01 Durango charging system
Replies
14
Views
586
1STMP
1STMP
Auto Transport Service
Back
Top