MR RIZK

iTrader: (7)

no codes as per first post. checked again for any soft codes but none. I will try the stock ecu however not sure how it will deal with the cams and 750cc injectors.

I have to ask the stupid question. Is it normal for a low comp vq35 with cams to naturally run higher idle. What are others experiences?

ddc665350ztt
Base ignition timing on passthrough is 15 deg.
The target idle can only increase not decrease the idle when using the consult
When the a/c is turned on u get the load compensation idle flare then settles back to 1k
Haltech does not control the DBW

djamps

iTrader: (1)

Didn't realize you are having this issue after building and adding cams... so yea lots of variables here I didn't think about. Stock ECU should be able to idle the 750's if you can lower the fuel pressure enough.

MR RIZK

iTrader: (7)

i will give it a go. my base FP is ~42psi with vac connected and ~52psi when not from memory

binder

iTrader: (8)

stock idle is actually 650

the idle is set based on coolant temp but you posted those already. You said you had your cam timing adjusted. Try to put the cam timing back to stock and see if that changes it. I don't think it will but it wouldn't hurt to try it.

Before i flashed a higher rpm my 9:1 engine idled the same rpm as stock except i had a lower vac (due to low compression and cams)

binder

iTrader: (8)

also, there was a user on here that had this issue and i can't remember who. His car idled at 1700 when they first started it and i remember it taking a while to figure out the problem.

deanfootlong

iTrader: (10)

Mostly posting here to get results. But ill give some more of my opinion while im at it.
I agree, try just the stock ecu. Mine seemed to idle with a return system, 600's and a walbro just fine. So im betting your ecu will handle it at least to check it. Also, I get the p0011 and p0021 can codes with haltech also. But I just copied the stock cam timing map. Haven't tried copythru. Probably wont make a difference. Have you tried playing with your base fuel map around those rpm's? You can massage out that "hunt" you have in the rpm range by playing with the cells of the base map.

Strange issue you've got there. Im in for results.

binder

iTrader: (8)

i don't think it's a fuel issue or you would see that on the afr on the haltech when you are monitoring it. It will idle slightly higher when there is unmetered air coming into the engine but a lean a/f mixture really won't move it up 400 rpms.

MR RIZK

iTrader: (7)

Quick update.

Tried stock ecu but it wont idle with it. Starts fine but just after a few seconds it dies. I haven't reduced the FP though. I tried holding the rpm high but still cannot get it to run with the stock ecu. Checked for codes after many cranks and no codes listed.

Binder you menetioned the cam timing but my cam timing in the haltech for that load point is set to 0 so I don't believe i have played with the cam timing. I tried disconnecting the solenoids for the fun of it but no different.

Yes i agree stock rpm is 650

I found this post which is similar but I got no response
https://my350z.com/forum/intake-exha...uum-leaks.html

The manual says it could be a stuck EGR valve but I don't believe the 2003 has a egr valve and could not find any other references. The other symptions is too much oil, checked oil when cold and stitting on H with oil pressure reading just above 2 kpa at idle when warm

binder

iTrader: (8)

we don't have egr valve and oil wouldn't cause that so those can be canceled out.

So stock ecu would be too rich to run with those injectors. I'm baffled at this.

MR RIZK

iTrader: (7)

I'm going to replace one of the cam sensors as one was new and one came with the donor engine. I will put back my original one. The crank sensor is my original one.

Besides the block, heads, and most moving parts excluding pistons/rods and so forth the electronic parts which was used from the donor engine are:

1 x cam sensor
2 x cam solenoids

The heads where decked, overhauled and buckets adjusted with the new cams

One thing that i forgot to mention is that the heads are ported. However the porting was really only a cleanup not a true port on both the exhaust and intake. the intake was left slightly rough while the exhaust was smooth.

The other thing i noticed was that the first start after each idle learn the car will stall. second crank and the car runs fine then will increase to 1k.

What i don't undertsand is if the throttle butterfly controls the idle (and we have no choke etc) how is the idle sitting at 1k when the butterfly looks like it is in the fully closed position. You would expect an air leak but the smoke test rules that out. is there anything else that opens/closes at 70C besides the nismo thermostat

MR RIZK

iTrader: (7)

Replaced the cam sensor no change.

The haltech is showing -6.3psi at 740 rpm and -6.9psi at 1000rpm. From what i have read if i had a vac leak then i would have less vacuum.

If it idled around 800 i would be happy

Late night update: Replaced the TB back with the first one and started the car. Drove the car for a good 30 mins, the problem went away. Idle was perfect at 780-800, no stalling, stopping at lights, aircon, fan cycles all good. Then when i thought all was ok i went into the haltech software and configured tps for the TB since it was the other one and as soon as i set the value the idle returned back to 1000rpm. I set the values back to what they were but still stays at 1k

failsafe306

iTrader: (38)

Is the water temp sensor working okay?

binder

iTrader: (8)

ya, check water temp sensor. That could be weird but at the same time i would think it's ok if the haltech is reading the temps correctly then it would adjust based on the temps it is seeing.

My guess was the TB. Apparently there is either a bug in the haltech map you have (did you build the map on a previous edition firmware and then upgrade haltech firmware?) or there is something wrong with the throttle body. Put the values back the way there were before you configured them.

I'm thinking your closed value is too high which is actually keeping the TB open ever so slightly causing high idle. Is the throttle body perfectly clean? Mine was having idle issues and i cleaned the butterfly edges really well and it stopped. It had some buildup that was keeping it from closing fully.

binder

iTrader: (8)

this is what my TPS voltages look like. Yours should be similar since there isn't going to be too much variance in the TB.

what do your values look like?

MR RIZK

iTrader: (7)

pretty sure temp sensor is ok as it close to the defi gauge that is also running. The TB is clean as when i assembled the engine i cleaned it. The map for the haltech is the same map i was running before the build for the last ~2years . All we did was retune under 0 vac for run in.

binder

iTrader: (8)

and it wasn't have issues until you did this retune? So have you upgraded firmware since then? Firmware has changed once and maybe even twice since 2 years ago. It seems like most people that have issues is due to a map being made on 1 firmware and then used on another. Or since now you updated the tune with a new firmware it could be getting confused.

I would do the TB reset then go into haltech and re-learn the TPS and APP voltages. Your app voltages look odd. They should be both above the TPS voltages but i'm not sure if this will affect anything.

I think that haltech uses that APP for something and since it's lower than your TPS it might think you are pressing on the pedal.

GO now and do it. i'll wait here impatiently. but seriously hurry because i have a ton of rtv to scrape off of engine parts so i can assemble my engine when it's finished being machined this week.

MR RIZK

iTrader: (7)

lol.. it is too late now 2:00am my time.. Please don't wait for me..

Im running 1.06 firmware and 1.07.4 software. The map was built from scratch when 1.06 came out as I had odd issues then so just started from scratch.

I will do some more testing tommorrow and post back..

binder

iTrader: (8)

ya, with that app lower than tps i think the car is confused and thinking the pedal is being pushed down.

the reason it wouldn't do this until the car warms i think would be due to the auto enrich when the car is started.

djamps

iTrader: (1)

Mine idles around -10psi..... yours seems low.

MR RIZK

iTrader: (7)

djamps, What comp and cams?