Car runs fine.
The car does start up however..
It has a hard time cranking over strong and crisp. Its just a bit weak and it takes a few seconds to start up when cranking.

It wants to start but it just isn't as crisp as it should be.

550cc RC injectors
D16z6
Vitara Pistons
H beam connecting rods
engine management eCtune

 

could be a number of things. I think there is more than one crank, no start threads around here somewhere.

Check timing, battery charge, compression, spark, fuel pressure, just for starters.

Good luck.

 

timing is fine, battery charge ok, compression is about 7.5 to 7.75 (low comp vitara build), spark is fine changed plugs yesterday, fuel pressure is fine..

 

I think you answered your own question. The only logical next step is to swap your ECU with a known good one if that's the only thing in question.

 

It sounds like your describing a slow crank...
What is the voltage at the battery?
What is the voltage at the battery WHILE cranking?

 

I believe the voltage was around 13volts when car is off if that makes any sense.
I had the parameter displayed on my tuner view but I cant recall the exact number

 

Pyro made a good point. Sometimes, it will appear that the battery is good, but if you're getting wierd symptoms, then your battery could be going. It has happened to me a coulple of times. Try replacing your battery with a known good one just in case.

 

normally if it volts drop below 11-10.5 volts cranking it's rotates really slow but it'll say 12.8 volts when not cranking

 

10.5 volts during cranking is usually the number I use. If your dropping below this during cranking, you probably have a weak/old battery...Check with a voltmeter actually on the battery itself...
OP- Do you mean the engine seems to crank slower than normal? Im not 100% what you mean by not sounding "crisp".

 

when the engine is hot, it tries to start but its sluggish to do so..

when the engine is cold (been sitting all night) in the morning the car start one shot.

 

I think you should have the charging system checked...

 

I don't know if you did this or not but to get a good read of the battery you need to remove the surface charge first. You just run your lights for a min before you measure. A good battery should be 12.6 V or higher and the charging system should be 13.5-15 V.
Cranking voltage should be about 10 V.

 

Hmmmmm...

When you did the compression test, was the engine hot or cold? Could be an improperly seated ring or worn/leaking valve/guide/seal. That would explain the better starting while the engine is cold.

 

The engine was rebuilt 8 months ago..

Compression test read 160 across the board, with cylinder # 2 at 155..

 

If you want more responses, you should follow the troubleshooting procedures that we are advising you to do. It seems like every time we ask you to troubleshoot in a specific way, you shun us as though you don't need to do it.

In my experience, the source of the problem is usually something very simple. I know I have personally done exactly what you are doing now in trying to troubleshoot random problems. We tell you to start with the simplest thing, and work up from there to spend as little money as possible.

Just because the engine was rebuilt 8 months ago or even yesterday does not mean it is in perfect condition and should therefore be eliminated as the culprit.

I'm done trying to help until you post the results of every single troubleshooting step given to you thus far showing that you followed our instructions EXACTLY as perscribed.

 

It sounds like your describing a weak battery....By sluggish, you mean its cranking slower than normal correct?
So if you had a bad alternator and your driving your car, you are running off the battery ONLY. This would explain slow crank on hot restarts.

After sitting all night, the battery has had a chance to re-coup so to speak. The next morning it seems to start like its got a good strong battery right?

Do you see how a bad alternator could be the issue? If it were me, Id drive on down to autozone or whatever store you have and get it tested. But call first to make sure their in car charging system tester isnt broken.

 

If it were a bad alternator there would be a point where the car no longer has any current to run or even start. The battery isn't going to charge itself overnight and allow you to start your car over and over without some form of charging system(an alternator).

 

if the battery is good you could try playing with the cranking duration on the injectors in the ecu

 

12.8v when car is off

battery dropped to 8.9v when cranking 8.7

when the car is on, the battery is 15.0 v

 

BINGO!

Replace with known good, and retest.

 

yup the battery is dropping to much meaning the cells are weak and not retaining much amperage in them man

i was going to ask what fuel your running because e85 is a pain when its cool outside lol

 

Also check for poor or loose electrical connections at the battery positive post, ground post, chassis ground strap and starter connection. A voltage drop test with a volt meter across any of these connections while cranking will tell you if you have a poor electrical connection. .1 volt across each of connection is about the maximum you want to see. Good luck.

 

can a dying/weak battery have a toll on any engine components?

can it also rob engine performance? and cause MPG to decrease?

 

Maybe. If your charging system is faulty, then yes. Not enough spark getting to plugs will cause you to run rich resulting in loss of power, and consequently, MPG.

A faulty batter in combination with a bad alternator could certainly be an issue.

 

battery tested out and it works fine

voltage: 13.02V
measured: 513CCA
rated: 410CCA
Temperature: 20 deg celsius

could a bad/dying starter effect performance?