Hey, just swapped some ZZ4 heads and proform roller rockers onto my 350. Never had a hard start problem before. At the same time as doing the head swap I replaced the starter since the old one broke.

If the car has been sitting for atleast an 30 minutes or so, it will jump right on, start beautifully. BUT, if i let it run for a while, shut it off, and try starting it again either immediately or even within 15-20 minutes, it will crank about a half turn. Then the starter will CLICK CLICK like it would if the battery was dead. It usually takes about 10 seconds of clicking and partial cranks to start up. I've never not been able to start it, but the hard starting is really inconvienent. It happens every time i run into a store real quick, get gas, any time I have to shut it off for just a few minutes.

I thought maybe the higher compression (from 8.2:1 to 10:1) might give it problems but that would be all the time, not just after its been running.

I pushed the timing back to about 6 BTD incase it just had too much advance, and it didnt change a thing (had it set to about 12 BTD before)

Last thing I can think of is that I have the rockers too tight. Maybe the preload on the lifters is too high (I did zero lash plus 3/4 turn) and after it runs and the lifters get oil pressure in them, it gets harder fro the starter to crank it with the spring pressure giving the cam a hard to turning.

I havnt tried backing the rocker nuts off a bit yet, but didnt want to unless it seemed like a possible diagnosis.

the hard start isnt that it will crank and not start, its that it is having a lot of trouble cranking after its been running. For some reason the engine is either harder to turn after it's been running or the starter has problems after its been running.

Any help would be great!

Thanks,
Oliver

 

Typically that's "heat soak" - the starter and/or solenoid windings get hot, resistance increases which lowers current, current is what produces the magnetic force to run the starter motor, lower current means lower starter motor power.

Could also be a weak starter. Not unusual for a new or rebuilt part not being up to snuff.

Or, could be a poor electrical connection to the starter.

 

bad starter, to far advanced timing bad ground, or bad connections

 

Hm. I'll check the wiring out, maybe a dedicated ground strap to the starter from the batt. It was just an autozone starter. New I should have gotten a nice high torque one from summit.

Thanks,
Oliver

 

I had that problem with my 383 w/mini-high torque starter under SLP headers till I replaced the battery with a OPTIMA Red Top, and the battery cables. The positive cable I bought is OEM, the negative I got at the parts store.

My CR is 11:1 and initial timing is 10° and it spins right up hot, or cold.

 

I can imagine the heat is getting to the starter and the cables. I have OEM heat shield sleeves on the starter cables where they get close to the headers. Those damn headers get bitchin hot after like 30 seconds

 

The "click click" pretty much rules out compression or timing.

 

I know compression and timing are fine, just wasn't sure if upping the compression ratio could be enough to give the starter a hard time. Regarding how close the starter and its wires are to the hot *** headers, I'll probably got the route of checking connections and maybe adding some heat wrap to the pipes that have close proximity to the starter.

 

Battery cables go bad internally where you can't see it, normally the first few inches of the battery positive terminal cable more than the ground.

Exhaust pipe heat wrap is probably not a good idea for a daily driver. You may want to do a search on why not.

 

I'd be interested to hear why wrap is a bad idea, my friends Trans Am has had wrap on the headers for over 5 years now and no problems.

 

I havn't investigated, but I can imagine that if it's driven in the rain the wrap would get wet (I don't even know if that could do anything to it or not). I can't think of another reason, but since I won't be using any I didn't look it up.

 

i had this issue with my car last year, turned out to be the battery not being strong enough

 

I had thought that might be it, but if you drive it nearly everyday I would think the heat would boil out any water pretty quick. I've known to be wrong though.

 

I guess I could find a definite answer if I wasn't so damn lazy. Guess it'll just remain a mystery.