How's it going everyone, hope all is well and hope everyone had good Easter with family.

I got some update, thats off topic...
But since we already here might as well just bring it up

So as of late I noticed I been having slow cranks..
Sometime it would just fire up, but most are slow cranks..

Just the other day I was driving around doing errands, I shut it off when I got to the store and went back to start it, really slow crank * after that the ses light comes on.

I scanned it "Code 36" No High resolution? I'm confuse cause I replaced optispark when I installed that cam in September.

Another thing, "voltage dips" I've been dealing with this for awhile and I have talk to Fred about this on another thread. Especially when put in gear voltage will dip and lights will dim out for sec. I pretty sure this involves "Code 36"

I pulled the pcm fuse for 30 sec from the fuse box inside the car. I started it and there was no ses light on the dash... But scanner picked up code 36 with code 51, "prom error" both codes are stored, but say "Current" on scanner.

I do have a MSD blaster coil installed and I heard a lot of bad things about it.. When I think about It i didn't start having these slow cranks until the MSD coil.

I read on some threads that slow cranks can cause code 36 and code 16 to come on in some cases.. It could also be wire related.

I just replaced alternator & battery too.

This car drives real good and still have lots of power.

What you guys think? Especially since that code 51 is back. Can low voltage cause all theses issues?

 

I’d get that new battery tested, and double check the connections from it to the starter and alternator. There’s really nothing else that causes slow cranking.

 

Just to be clear.... by “slow cranks” you mean the starter labors to crank the engine, and it turns slowly? You do not mean that the starter appears to turn the engine fast enough, but the cranking time period is extended, before the engine actually starts.

When the starter is cranking the engine, what is the voltage shown on the dash gauge?

You may have posted this before, or on another site, but I reply to so many people on the 3 different sites I follow, that I can’t remember all the details. A link to any previous thread you posted on this topic would be helpful.

Please add a signature.

https://www.camaroz28.com/forums/lt1...nature-879835/

 

Yes that's what I mean, I'll start it, but turn over slow. Sometimes it would start right up.

​​​​​​The voltage gauge function normally when cranking, but while running, the gauge will dip to 12. 8 then back to 13.3 random times.

Especially sometimes when put in drive or reverse, it would dip dramatically.

Okay I will fiil that out.

 

I check the wires leading to the alternator and starter and I didn't see anything abnormal.

Might have to double check again.

 

Given your responses, I'd take both the battery and alternator in for a bench test. AutoZone will do it for free. I believe Advanced Auto will too.

 

What does “functions normally while cranking” mean? Normally, the voltage will drop when the starter is cranking. What is the NUMBER the gauge needle drops to when the starter is working hard to crank the engine? Can your scanner display the system voltage? Use it while cranking. Do you have Scan9495 so you can generate a data log while starting the car? Very low voltage can leave the PCM unable to process the data, but there would be a code for that. DTC 51 indicates the EEPROM has experienced a programming error.

Does the engine have an underdrive crank pulley? That can lead to low voltage at idle, particularly with an auto trans.

When you “check(ed) the wires”, did you unbolt both ends, and examine the terminal end of the wire and whatever it bolts to ( block, battery, starter, chassis, etc.) for corrosion? Did you examine the wire ends for broken strands and corrosion creeping into the strands?

 

Whan start my scanner shows 12.7 - 13.0 I don't know if that's a good range or what but that's what it shows on some slow cranks

​​​​​​Can low voltage cause code 36 and code 51??? This is not the first time these codes has popped up..

My scanner still shows code 36 & 51 stored, but not on dash.

And no I don't have underdrive pulleys, it looks all stock to me.

I didn't get to expect it that good.. There are some dusty grounds that connects to the battery terminal on Passager side above the battery..


I do want to bring something up that's been brought to my attention, and maybe it relate to the low voltage issue. It's a little off topic, but it might help.

Today before I had work I was changing out my old BBK tb with new BBK tb, and now I had bought my old one used. The owner mentioned that theoold TB is a 52mm.

So today I had them side by side comparing both, and the Size difference was very noticeable

I'm assuming the old was actually a 58mm.. Anyways since the change I haven't had not so much voltage dips the whole day.. It holds the voltage way better then the old... Slow cranks slightly went away.

Running a 58mm TB is overkill right? Unless you have a huge cam and major mods.

I heard 58a can cause rough idle and other problems if you don't have the right mods

But Is it possible that bad airflow can cause charging issues?

 

Let's try this one more time.

Turn the key to the “RUN” position. Do not attempt to start the engine. What does the voltage gauge read?

Turn the key to the “START”position. Does the voltage DROP. If so, what is the reading? It is NORMAL for the voltage to drop when he starter engages.

When. the engine starts and is now idling, what is the RPM and what is the voltage? NORMALLY, after a hard start the voltage regulator in the alternator will bump the voltage up to rapidly replace the energy drained from the battery by the starter. A reading of 16 volts wouldn’t be unusual. Voltage will gradually drop down to 12.5 - 13.5 volt range.

Now, put the trans in gear. What does the RPM do, and how low does the voltage drop? Does the RPM recover, and the voltage rise with it?

For sanity's sake, where did I discuss “voltage dips” with you in another thread, because I can’t find it on this site?

An underdrive pulley reduces the charging capabilities of the alternator by slowing it down. At idle, with an auto trans, the set idle speed can be low enough to cause the battery to run down.

Does your crank pulley (damper) look like this?

From Shoebox:

http://shbox.com/ci/balancer_hub.jpg

http://shbox.com/1/pull_pulley.jpg

= = = = = = = = = =

THROTTLE BODY

Stock throttle body has 48mm bores. The stock intake manifold has 52mm bores. Putting a 58mm throttle body on 52mm intake bores creates turbulence the probably hurts air flow more than it helps. In any case, there is no connection between your 58mm throttle body and “slow cranks” Use your Tech-2 to see what the IAC counts are when the starter is cranking the engine.

https://www.camaroz28.com/g/picture/13793301

The guys that built my engine were able to show me, with the engine running on a fully instrumented engine dyno, the my 58mm Holley throttle body was overkill at 490 crankshaft HP. The engine made that power with the throttle at less than 100% open, and opening it further did not increase HP. And yes, my LT4 intake had the bores opened up to 58mm.

stock:48mm LT1:

https://www.camaroz28.com/g/picture/13793397

modified 58mm LT4:

https://www.camaroz28.com/g/picture/13793481

I still need to cover a couple other issues you raised but this post is long enough.

 

When in open loop volts are at the 13.5 range.
It drops down to 13.2 in close loop.. But as it warms up in open loop volts drops to 12.8 randomly... When warmed up, voltage is more stable and don't dip as much.

So usually when i put it in gear (Reverse/Drive) Voltage would drop to 12.4, Rpm would drop to 655 and sit there until I give a little throttle it gradually go back to normal...

Sometime it would seem like it would about to stall out when put in gear, these symptoms would be more presence when the car is warm.

But since I accidentally erase my tune recently with the hypertech, Solomon had made some adjustments to the idle when I mentioned to him about the voltage issue.

Since then the idle and voltage hasn't been that bad, not fixed but way better then before

Yup I definitely have a stock harmonic balancer, they look similar.. I probably need to go through my wires real good and clean them..

Unfortunately Fred my tech 2 broke, I have another scanner though.

I thought the stock TB is a 48mm? My stock Is smaller then then my BBK 52mm TB

I agree, definitely overkill.. I heard that 58mm TB causes issues even with a tune.


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Here size comparison between my old BBK & new BBK. Size difference right?

 

Correct, stock is 48, my error.

One on the right looks smaller.... but just measure the diameter of the bore opening in the back.

52mm = 2.05"
54mm = 2.13"
58mm = 2.28"

Stock 48mm - Front

https://www.camaroz28.com/g/picture/13793382

Stock 48mm - Back

https://www.camaroz28.com/g/picture/13793386


Holley 58mm - Front

https://www.camaroz28.com/g/picture/8154357

Does the new one NOT have a removable top cover?

 

The new one no.. The old one does have a removable cover. Red BBK edelbrock cover.

What's the difference?

There are some differences between the two. Especially the holes..

The air tunnels on the old are different then the new one that has a hole that goes straight through.

 

This is the first time I have seen that BBK design on the right. I have no idea why they changed it, or what the differences are. I checked BBK website, and they show the new design on the right for our cars in both 52mm (part #1543) and 58mm. (#1544).

 

I got this online from ws6store..
Originally I was supposed to get the BBK edelbrock one with the removable cover

But ws6store contacted me to notified me that they was out and that they will not be having that design anytime soon.

This design is the only one they had..
If I'm not mistaken, I've seen impalas run this same design TB (No removable cover)

Maybe there was some errors they picked up on the last design..

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