SR20ve Hunting (solved) - Apparent Leaning Now

[V2NR 3.0]

This challenge recently started happening.

Its a SR20ve N.A.

1. Car "hunts" once engine is at operating temperature and on idle.
2. Car "hesitates and breaks up" (almost like boost) between 2700rpm-3200rpm or there in between.

Ive thrown the diagnostics on the car and No Codes.

Timing ? Fuel Delivery ? Fuel Pump On Its Dying Stage?

Everything is fine - im thinking it could be a tiny problem...any similar experiences / guidence ?

Much thanks

[rollingstock]

Could be a dirty intake, use a wynn's and see if it helps, also when you did the diagnostic did you check the pressure at the four injectors.

[praise]

Are your injectors clean? When last did you replace spark plugs and what tyre of plugs are using? What is the current timing? Is it 15 degrees before Top dead centre with TPS unpluged and idle at 750 rpm?

[V2NR 3.0]

I will try the items enlisted.

I strongly believe that the timing on the engine is off. We did not time back the engine and just replaced the distributor. Checking that this evening as well.

Could timing affect of cause hunting issues ?

[xtech]

my Toyota turbo engine used to sound like that.......
starts great but when it warms up then the hunting begins also did the hesitate and break up when driving off in the same RPM range when boost kicks in......installed a new walbro 255 problem gone the cheap fuel pump was dying

[biggreen]

^x2 had the same prob and did the same thing and prob was gone.. - the hunting

[V2NR 3.0]

xtech & biggreen: ^x2 had the same prob and did the same thing and prob was gone.. - the hunting

^ I have a walbro high pressure fuel pump installed in the car. Unless it has run its life - a little over 3 years. Will know for sure this afternoon into tomorrow. Thank you for your thoughts.

[V2NR 3.0]

Are your injectors clean? When last did you replace spark plugs and what tyre of plugs are using? What is the current timing? Is it 15 degrees before Top dead centre with TPS unpluged and idle at 750 rpm?

^ I researhed and saw that timing on a stock ve is 10 degrees ? - where did you find your info from man ? Checking back plugs and TPS set up after wk today, will pot findings. Im running Iridiums R7

rollingstock: Could be a dirty intake, use a wynn's and see if it helps, also when you did the diagnostic did you check the pressure at the four injectors.

^ Will take this into consideration. The individual cylinders were firing perfect. No injector issues present either.

Wil update findings for the benefit of all once sorted out.

[krack korn]

timing is 5 deg for 20VE, 10 deg for 16VE.

clean the MAF, if possible try another one if u have a spare handy. I have seen a similar problem with a faulty maf.

[V2NR 3.0]

timing is 5 deg for 20VE, 10 deg for 16VE. clean the MAF, if possible try another one if u have a spare handy. I have seen a similar problem with a faulty maf.

Had some interesting discoveries when i investigated. The brand new R7 iridium plugs that i installed were not there - Instead found R6 plugs beaten to death...rather strange how that got in there. With this discovery im wondering what else was "replaced" or "accidentally switched". I also discovered that the AC step up was not wired inn (although i was told that it was) nor is my IAC valve hooked up either (same thing told here)

Moving on, I changed plugs, adjusted timing to 10 degrees and the hunting and hesitation stopped.

Took the car for a spirited drive down sdo from san juan and back up. Car pulled perfectly, or at least, thats what i thought.

When i reached home i pulled the plugs and it was white like chalk. Still in the brand new condition...Adjusted furle pressure to 45 then to 48 with no changes in fuel delivery.

Any thoughts? - Gonna check fuel filters, high pressure walbro fuel pump (hopefully that was not swapped) and take it from there.

[Aaron 2NR]

hmmm swapped you say.....

left the car by a new mechanic or something?

[dry]

What ecu? DE ecu should have base timing at the regular 15. VE ecu, set as krack advised. Look for air leaks between maf and tb. You are definitely lean and that can happen when the engine pulls air through a leak rather than through the maf. It can also cause the hunting.

[krack korn]

heat range 6 is correct for the engine anyway. If you are always running high rpm's then 7 will be better.

AC step up(also step up for PS and other high electrical load accesories like rear defogger) will not affect idle quality unless ac is on or you are locking the steering etc. This is the purple plug solenoid.

Highly unlikely that IACV (brown plug) was not hooked up, car would not have idled well at all and you would have serious drivability issues especially low down and pulling off etc. This was all working before not so?

What was timing set on before u adjusted it? What ECU are you using? I have never had problems with 5 deg using the SR20VE ecu.

Are you adjusting fuel pressure with the vacuum line disconnected?

What about the TPS? Anywhere from about 0.35 to 0.5V is ok.

[V2NR 3.0]

bumpty to bump

[V2NR 3.0]

Aaron 2NR: hmmm swapped you say.....left the car by a new mechanic or something?

^ Hey, accidentally switched - no new mechanic.

dry: What ecu? DE ecu should have base timing at the regular 15. VE ecu, set as krack advised. Look for air leaks between maf and tb. You are definitely lean and that can happen when the engine pulls air through a leak rather than through the maf. It can also cause the hunting.

^ Its the stock VE Ecu and i'd re-adjust my timing to 5 degrees later on today. No air leaks. But as mentioned before, hunting and hesitation are no longer present.

Mission this evening is to examine the fuel pump, fuel lines and filters.

If my walbro is not in the tank, you guys would know for sure.

[V2NR 3.0]

heat range 6 is correct for the engine anyway. If you are always running high rpm's then 7 will be better. AC step up(also step up for PS and other high electrical load accesories like rear defogger) will not affect idle quality unless ac is on or you are locking the steering etc. This is the purple plug solenoid. Highly unlikely that IACV (brown plug) was not hooked up, car would not have idled well at all and you would have serious drivability issues especially low down and pulling off etc. This was all working before not so?
What was timing set on before u adjusted it? What ECU are you using? I have never had problems with 5 deg using the SR20VE ecu. Are you adjusting fuel pressure with the vacuum line disconnected? What about the TPS? Anywhere from about 0.35 to 0.5V is ok.

For the application, R7's is suited. The reference point of the AC and other items not being hooked up was an observation. The IACV had to be re-hooked up. The timing was set at 0. The fuel pressure was set with the line disconnected (tried and experimentated) and then re-adjusted with the line on - made no difference either way in terms of plug readings. TPS is working fine.

Scanned using the nissan blatz program and the items aforementioned were corrected.

Looking at fuel system later on...It could be a simple fuel filter clogged up since the car was parked for 3 weeks and then removed.

[krack korn]

you cannot set the timing using the blazt cable. You can only put it into timing mode (set base idle). The timing you see displayed is what the ecu is running at that instant relative to the physical setting of the distributor. The ecu has to assume that you have the distributor set correctly. If for instance you have the dist physically set at 10 deg then what you have displayed on the screen with the blazt is actually 5 deg less that what it actually is.

With the VE in particular, always verify that the TDC mark is correct on the crank first, by using a screwdriver (or other probe) in #1 or 4 cyl. Then set timing using a timing light. The VE crank pully is notorious for being out, the outer ring slips on the rubber. The outer ring has the timing marks. Once it slips it no longer has the correct 'as new' orientation.

In the active settings you can temporarily add or remove timing in a fixed amount across the board (entire RPM and load range), the cable has to remain connected to maintain this setting. The ecu automatically adds or subtracts the amount of timing u specify after doing its calculations to the ignition timing only. Turning the distributor to advance timing also affects fuel injection timing.

I noticed you have an AEM uego, what afrs were you seeing? This could possibly be your O2 sensor as well. What are your AF base and AF self learn values (from data scan)?

[V2NR 3.0]

you cannot set the timing using the blazt cable. You can only put it into timing mode (set base idle). The timing you see displayed is what the ecu is running at that instant relative to the physical setting of the distributor. The ecu has to assume that you have the distributor set correctly. If for instance you have the dist physically set at 10 deg then what you have displayed on the screen with the blazt is actually 5 deg less that what it actually is.

With the VE in particular, always verify that the TDC mark is correct on the crank first, by using a screwdriver (or other probe) in #1 or 4 cyl. Then set timing using a timing light. The VE crank pully is notorious for being out, the outer ring slips on the rubber. The outer ring has the timing marks. Once it slips it no longer has the correct 'as new' orientation.

In the active settings you can temporarily add or remove timing in a fixed amount across the board (entire RPM and load range), the cable has to remain connected to maintain this setting. The ecu automatically adds or subtracts the amount of timing u specify after doing its calculations to the ignition timing only. Turning the distributor to advance timing also affects fuel injection timing.

I noticed you have an AEM uego, what afrs were you seeing? This could possibly be your O2 sensor as well. What are your AF base and AF self learn values (from data scan)?

1. Did not say i was going to use the blatz for setting the timing, this was used to see the values.

2. I am familiar with setting the timing bro

3. The Uego not hooked up, will post the O2 sensor readings later on.

4. Do you have a handy MAF around the place ?

[krack korn]

Scanned using the nissan blatz program and the items aforementioned were corrected.

I was going on that statement, plus u cannot verify timing either all u are looking at is what the ecu is programmed to do, this has not changed. So seeing the values is of no use if u think timing is out. It is only of value if you have the ability to change the ECU programming. Only a known good TDC reference and timing light can set timing.

Not everyone knows even many mechanics so its better to say it than to not. Also usefull to anybody searching in the future.

The Uego not hooked up, will post the O2 sensor readings later on.

BWTA is just power u need to hook up and if you have the sensor installed without the controller/gauge being powered up and connected to the sensor its already fooked. Sensor cannot be placed in exhaust stream without being powered by controller. (I dont know if its installed but your FS ad says it is so again thats what I'm going by).

I do have a MAF but pm me about that.

[V2NR 3.0]

krack korn: Only a known good TDC reference and timing light can set timing.

^ Correct is right.

I dont know if its installed but your FS ad says it is so again thats what I'm going by

^ Correct is right again. It was but, corrective measures and exhaust work caused it to be off.

PM Sent

[V2NR 3.0]

Update Everyone,

Just as i suspected - the walbro filter was jam packed, when asked with what - the mech said sand. In doubt, and not believing my eyes, i looked at the fuel pump holder which is located inside the tank and there were physical grit. The little white bag at the end of the walbro pump was black...

Clened it out properly and changed all flters, re-set Fuel Pressure and the plugs are nice and brown indicating good fuel delivery.

Becareful people who and where you take your vehicles

[Supra GT-FOUR]

Heat range 7 plugs on the VE?
like you in the mood for some boost vinod

[V2NR 3.0]

Becareful people who and where you take your vehicles

Found the culprit

[Aaron 2NR]

call names

[V2NR 3.0]

call names

Well:

1.Spark Plugs Swapped
2.Sand In Tank
3.Car Wired Like sheit - Twice (which is throwing off timing badly. Car parked up until Saturday)

Funny...me aint even see the man jump on this thread...life goes on

Calling names is irrelevant. But here is the solution:

Basically, we opened back the gas tank to see what was going on with the state of the filter and the pump. The pump and filter were in the same condition as we left the afternoon before. Further testing, we wanted to see what the pump was doing under load. We removed the bonntet and strapped the aeromotive regulator to the wiper and run it down a backroad. The pump responded fine and thus eliminated the fuel pump and fpr. This was fun.

Pulled back into the garage...engine on...blatz connected....minds being put together thinking.....Using a timing procedure provided by Krack (mentioned higher up), we put the engine in timing mode and set the timing to 5 degrees. Then boom....the fans come on and the entire engine dies, idling very very low. At this point the timing is checked only to see it retard 10 degrees. Once the fans come off, we tip the throttle body and the idle stabilizes and the timing is reset. Fan comes on, timing thrown off....The blatz confirms all that we are physically seeing.

So the problem is electrical in nature.

Good experience.....

Poor Electrical works from a guy who claims to be a very good elctrical guy

Will keep updates coming

[Sookdeo]

yo V2NR 3.0, check ur PM

[VexXx Dogg]

call name!

[Aaron 2NR]

is this the same mechanic that did the swap for you? or someone else?

[Maserati]

http://forums.trinituner.com/forums/vie ... ight=booge

[V2NR 3.0]

Guys...problem set to be sorted out completely on Saturday...Lets move past the name calling...Just be careful guys