Slow crank when hot

[alex]

I have a mystery I need help solving.

After driving long enough to get the engine hot (like down the street to the store), when I get back in the GW to go home it will crank very slowly. Sort of "craaaannnnkkk - pause - craaannnkkk - pause - craaannnnkkk" and then it usually starts. If it doesn't start by the third slow crank I'm dead until I let it cool down. After cooling down she'll start right up.

In attempting to solve this I have replaced:
Battery (with 750 cca one)
Starter Relay
Positive and negative battery cables
Cable from starter relay to starter
Starter

I have also cleaned the battery grounding location very well.

What else could this be? How should I go about diagnosing this?

We're talking about an '85 GW with 360

Thanks in advance.

Alex

[jeepbob]

back the timing off a hair (retard)also try pumping the gas to SLIGHTLY flood the engine. also you might want to check the amp draw when starting, the starters usually draw 350 to 450 amps when cranking.

[ClarkGriswald]

Yep. check your timing.. this is a classic symptom of having it to far advanced..

[RustyJeep]

I had this happen on a VW Jetta before, so I don't know if it'll work but give it a try: The starter heated up to the point that it drew more amps, so we put a heat shield on the starter and it was fine. Heat shield (ie license plate) worked great. Just a thought.

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RustyJeep
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Project "P.O.S."
'82 J-10 258 4 Speed
Bone Stock...For Now
w/"Custom" Air Vents
Plaguing the Vehicle
Can anyone say, "Fred Flintstone" here?

Winter Car
----------
'85 AMC Eagle
258 cubic inches of pure...umm...power. Yeah that's it.
Lifted Eagle comes to mind.

Summer Car
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'79 Pontiac Grand Prix
65,000 original miles
301 4bbl with plenty of go.
Top speed unrecorded as my speedo drops off
and I've still got a long ways to go. :)

[bigblack'74]

exhaust manifold is directly next to starter and when it burned mine up it started to crank slow then eventually just wouldnt turn at all. i also thought my timing was too advanced but i just busted out a new started and all was good

[SpruceMoose]

i have the same problem too, but not all the time. sometimes it acts up, but mostly its perfect. i have heard about the early timing possibility, but i havnt had a chance to test the theory. my test will be: when i have a cranking problem, pop the hood, pull the high-tension lead from the center of the distributor cap, and ground it. then crank the starter. of course it wont start, but since there will be no spark in the cylinders it cant be an early spark trying to push the pistons back down before top center.
sounds good, anyway!
if that shows no effect i will do the heat shield thing.

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88 Grand Wagoneer
"Spruce Moose"
AMC 360, DANA 44 F/R 2.72, TF 727, NP 229
Jacobs Pro-Street Ignition, Edelbrock 4bbl Intake with Holley 2bbl Analog Pro-Jection
Flowmaster 2.5" 50 Series Delta muffler and tubing
Amzoil foam air filter, Amzoil fluids all around
30x9.5 BFG AT
HF,VHF,UHF ham rigs and too many antennas (not)

Mileage? We don't need no stinkin' mileage!

[andy d]

if the engine is that far advanced, it prolly pings under acceleration. check the timing. does this rig have the ford type starter, if so the solenoid could be starting to go.next time it happens,"jump " the solenoid. i use the handles of a non insulated slip joint pliers. if the starter cranks normally, its the solenoid or the connections to it. if the pliers start getting hot,its the starter.

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'88 gwag,pure stock

[jeepbob]

Amc motors will accept a lot more timing than most Ford starters can handle, especially if premium is used before they will ping. A cure for this is to find a rebuilt starter for a 73 to 75 International Harvester pick up or travellall with a v400 engine. (not the V401 or Vs401)it is a DELCO hi torque style with a solinoid built in (like a Chevy)and is a driect bolt up. run a wire from the existing ford relay to the s terminal to activate the sol. and a cable from the battery to the big bat post on the sol. The IHC v400 is an AMC 401 coupled to a 999 torqueflite tranny. Rebuilts can be had for a little more than than the Fords, but they are getting hard to come by. so it might even be worth while to scout the yards for old farmall fastbacks that may have a rebuildable one (the 401 also makes good trading fodder) one more tip, don't try to put a 290/304/343/360/390 oil pan on a 401, the con rod will reshapr the pan and it will make a lot of noise.

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65 wag. 360/edelbrock rb4/t400/20 t-case/4:10 d27/d44 tracloc/onboard air/onboard 110v power(no inverter)/1999 Lincoln t.c.leather buckets/taurus ctr console/winch/33x12.50/tunes/water proof door pads
soon to have new motor/d44frt/d60r(4:10)welded diff/custom bumpers
see ya in da mud

[alex]

I was skeptical, but backing off the timing fixed it.

Interestingly, the problem was occuring while the timing was dead-on at 12 degrees BTDC just like the engine compartment sticker says.

I backed it off to 9 degrees and that fixed it. I will try 10 and 11 when I have some time just for grins.

Also, for those interested, it was definitely not pinging. Not under heavy load, not on hills...never. And I run plain-old 89 octane.

Thanks a bunch for the help.

Alex