View Full Version : running out of ideas new sr build sucks

07-27-2013, 07:19 PM
OK...long story short its a new build everything is new. I have bucking issues and running rich. I've absolutely checked everything and I can't find shit wrong. Thing only thing different is the block is overbored 40 over with 264 came. Will timing need to be different since its bored over that much? I've ran codes on the ecu and Maf will come up and go away but its a new maf. The car only runs up to 2800rpms. Like it hit a wall. Could i have gotten a shit Maf? Or is my timing off because of the upgrades?

07-27-2013, 07:44 PM
Did you verify that mech timing was correct? Did you check that the CAS was stabbed correctly? Have you checked TPS and MAF voltages? Do you have an FSM to perform all of the asked above? If not, I highly suggest you get one and start trouble shooting from the FSM.

07-27-2013, 08:38 PM
The cas is set correctly,Maf and tps voltage is correct. I will get the timing gun out and check it again. If all is well there I don't know where to go next. Check for vacation leaks again?

07-28-2013, 01:51 AM
Mechanical timing right?

07-28-2013, 09:27 AM
Yes it is.

07-28-2013, 09:49 AM
Check your MAF voltage at idle. If it's below 0.7V, or drops below 0.7V when rev'd, that's the problem.

07-28-2013, 09:56 AM
Sounds like a MAF issue. Unplug the MAF and see what the car does. Also what MAF are you using?

07-28-2013, 07:21 PM
Have you had it tuned since you have done the upgrades? Might be the issue

07-28-2013, 09:26 PM
Youd only change the timing from having a shitload decked off the block and head, not from boring.

This is asuming you have a tune on an aftermarket ecu, and arent trying to run a stock ecu on a modified sr build

Crack your valve cover open and double check your mechanical timing, its seriously easy to overlook a timing chain moving a link on the crank, which would throw everthing out of wack. A timing light wont tell you if the intake cam is off a link. Checking that mechanical timing is number one.

Besides that, do some investigating on that MAF, not going over 3000 rpm is a clear indicator of limp mode (which is what happens when maf is unplugged). The "new maf" could have been dropped and broken. Which maf and ecu are you using?

07-28-2013, 09:27 PM
Check for major vacuum (coupler) leaks and the wiring to the main sensors (CAS/MAF/CTS)

07-28-2013, 11:10 PM
Thx for the replies. The ecu is a enthalpy. The Maf is a z32.also a wiring specialties harness. Ill check the voltage when its running and crack open the valve cover too. What would be a dead give away if its off a tooth? The last time i looked it all looked great but i may have over looked a problem.Ill try to take a pic so you guys see everything.

07-29-2013, 06:16 AM
Im copy pasting, so some of this information wont apply to you:

During timing chain or camshaft installation someone dropped the chain (knowingly or not) and it skipped a link pin on the crank gear. Then they used the black links (unknowing that theyve now been rendered useless) to align the mechanical timing on the cams. This is why you are on TDC, the cam dowel pins are in about the right place, there are 20 link pins between cam gear timing marks, but you cant get the cas stabbed without it being fully retarded or advanced. Evidence of this is the number one cam lobes being at the 9:30-ish and 2:30-ish position instead of 9 and 3 oclock while at TDC.

Double check all of this criteria is met simultaneously before you end up doing the procedure to fix a problem you dont really have. And do not ever assume the chain is installed so the gold link and timing links will ever align properly, thats mistake number 1 most of the time. This is for stock cam gears.

1) Crank is on TDC (2nd mark from left).
2) #1 Cam lobes are facing like this '<O C>' literally horizontally. And the butt of the exhaust side camshaft has a notch in it that looks like this '='
3) There are 20 link pins between the timing marks on the cam gears.
4) The dowel pin on the exhaust cam is perfectly upright and vertical.
5) the CAS has the orange mark lined up exactly with the slot once stabbed and is in between the bolts, well, just not close to all the way advanced or retarded.

To fix the whole "cant hit 15* without full advance or retarding of CAS" thing:

1) rotate the timing so that exhaust cam has its #1 lobe perfectly horizontal and facing outward.
2) remove intake cam gear.
3) adjust intake cam so its number 1 lobe is perfectly horizontal and facing outward.
4) leaving the cams exactly where they are, have a friend rotate the top of the chain while you turn the crank to exactly on the TDC mark.
5) install the intake cam gear and the chain onto both gears all at the same time so that there are 20 link pins between the timing marks on the gears. Keep in mind the slack in the chain will be primarily between the crank gear and intake cam gear and a little between the cams.
6) install CAS
7) install chain tensioner and rotate the crank twice around to realign the TDC mark, you should be on the power stroke (cam lobes 1 like this '<>').
8) double check criteria from before
9) check ignition timing.

If you cant hit 15* around the center of CAS travel after that, both of the timing lights you used are fucked up, you need to try another ECU and a 3rd CAS, then if its STILL fucked up, youll have to bring it to a professional SR20 guy to redo the procedure you just botched.


07-29-2013, 09:56 AM
Is the ECU programmed for the Z32 maf? Or are you using a SAFC?

07-29-2013, 10:15 AM
If you got your Z32 MAFS from Enjuku (ISIS Z32 MAFS), then the MAFS could definitely be the culprit... Hopefully this isn't the case... OEM Nissan is the way to go.

08-01-2013, 09:16 PM
Here's a pic I hope its clear. If not there came are fucking way off!its not at tdc but the intake is at 6 and the exhaust is at 10.

08-01-2013, 09:56 PM
Here's a pic I hope its clear. If not there came are fucking way off!its not at tdc but the intake is at 6 and the exhaust is at 10.

We can't see shit in that pix. Also, keep rotating the crank, it might line up where its supposed to be after a few rotation.

08-02-2013, 08:04 AM
^^Agreed. You may double check with Enthalpy if you haven't already. Would suck if it's just the tune not set properly for your mods.

08-02-2013, 12:25 PM
When this all first started I blew my first Turbo. I thought it was the tune. So they sent me a couple tunes that were leaner but I still had the same issue. I ran out of funds to buy the same Turbo so i hhad to down size and enthalpy gave me free tune for the set up. I will get the engine rotated tonight or tomorrow.

08-02-2013, 12:33 PM
Oh what size socket is the dampener bolt? 27mm?

08-02-2013, 12:48 PM
Yes, and, if you are truly 30yrs old you'd understand what I'm about to type. Most internet tech will avoid this thread, like the plague.
I on the other-hand,will walk you through and also have some patience. It will be very apparent if you are capable or not? At that point, I will have another suggestion.
Let's me know what you plan or don't plan to do, 100% dedication is not free.

08-03-2013, 06:12 PM
Well I checked the cams and they were in spec. Whatever the problem may be has to be very simple,so simple I'm over looking it.

08-03-2013, 07:02 PM
Sounds like a maf issue, either

Bad mafs
Ecu not tuned for n60

08-03-2013, 07:20 PM
I'm gonna try swtiching mafs and see what happens.