redd100

Hey all,
Well my s14 sr20 has been running great up until a couple of weeks ago. Out of the blue, the car started acting up on warm restarts. The car basically floods out whenever restarted. When started cold, it runs fine, no problems at all. I recently replaced the factory temp sensor, and replaced the ecu with another stock one to no avail. This issue is quite depressing, since i cant take it anywhere and restart the car ie restaurants or to even get gas at a gas station. Once the car has cooled down for about an hour, it starts again with no problems... (im also rockin ngk iridiums and warlboro fuel pump)

The next item im checkin is fuel pressure and replace the spark plugs

Has anyone has any similar problems that could lead me in the right direction?

Thanks for any help!
i am sad.. missin my boost.

japanesenut

Check your maf , tps , do you have wide band ? Defiantly hook up a fuel pressure gauge to it i. that will help in diagnosing your problem . lowes has the t , other parts you can use to make one . your fuel gauge will be 1/8 npt Just trying to help (i wish my sr was runnig rich at idle ) im just the opposite . lean at idle .

battosaii930

iTrader: (2)

might be ignition timing i had the same problem as you but oposite i had trouble starting when cold but easy when hot and i just had to adjust my ignition timing

redd100

Sadly, i dont have a wideband or a fp gauge, but i have a friend bringing over a fp gauge to check it. Tomorrow i will take it to a shop to have the ignition timing checked. I have checked the maf and the tps, both seem to be working normal.

Thanks for the advice guys! at least i have somewhere to investigate now.

Today when i drove the car after installing new spark plugs it starting to show another symptom. Once started and ran for awhile the car hesitates when stepping on the gas. No backfires, no smoke, boosts normal, but just doesnt have any pickup when full boostin. After cooling down and restarting, it drove normal for about 20 mins then started to bog down again...

This is just boggling my mind...
My poor baby..

battosaii930

iTrader: (2)

yea my sr was fine when i had it then it sat for a almost 2 years b4 i got it back in a car and running again and it had problems that it never had b4 but ive got most if not all of them worked out already.

you might need to set ingition timing back to stock i adjusted mine a bit but it wasnt perfect then i installed my new cams and i put the timing back to stock and ive never had a problem starting the car since.

heres the FSM


pretty simple if you want to do it your self.

redd100

Sorry it took so long to get back, I had a problem occurring with my other car... I installed a fuel pressure guage on my 240, and it stayed constant at 42psi even after heat soak. I followed all the fuel lines and checked for kinks etc. The fuel filter is a new 300zx. I think next on the list is to check the timing..

Can anyone tell me what the long metal sensor is located above the fuel rail? It is in the front of the engine, maybe four inches long with two wires coming out of it. Its located adjacent to the tps.

redd100

And thanks again for any advice! I took the car to a local tuner shop (mostly for subbies) and they didn't really have any clue what could cause this.

What a crazy problem to have..

It seems on warm restarts if i hold the gas in and crank the starter for awhile, it will slowly start. Sometimes not a all

battosaii930

iTrader: (2)

sounds like ignition timing did the same to me but when cold.

either put it back to stock like the diagram shows or u can get someone to be in the car and you adjust it to see if it works.

imo putting it to stock is very very simple

take out the CAS 2 12mm bolt and a plug. take off vavle cover. put the motor tdc. alight dots on the CAS like illistrated then put it in tighten it plug it put the valve cover back on and you should be good

japanesenut

The long thing by your tps has to do with your vtc thats the only thing i can figure ,i have it also .
Timing . (pull first coil out put spark plug wire on it hook coil to other end of spark plug wire , and hook up timing light normal after that . ) G.L let us know .

japanesenut

Ok idle control on our engine s14 sr20det ec 28 has thee vtc parts . ec32 is when the idle comes into play . Im having a issue's when i let off gas on a stop and its dieing (and im recirculated but may have hole in hose line .) Just trying to help .

redd100

I dunno if its idle related or not. When i do get it to hot start, it idles fine, just cant full boost or it bogs down. It will only handle a few lbs.

Heres a recap of what my car is doing:
s14 with s14 SR20

The car will always start when cold. Idles great, runs great, no hint of problem
When the car is warmed up, after about 30 minutes of driving, car begins to bog down at any rpm when boost is applied. The car wont restart after being driven. It will usually almost start, then die, and then theres nothing. I have to wait over 1hr while the engine cools back down before it will restart. Sometimes when hot starting i can hold the throttle down, crank the starter awhile, and the car will slowly start. If it starts hot, it idles normal but bogs down in any boost. 95% of the time it is hot it wont restart. Usually when i pull the plugs when it wont start, i find unburnt gas.

Mods:
Z32 MAF and fuel filter
Walboro pump
s15 t28
koyo radiator
cs catch can and turbo lines
HKS wastegate and bov
flexalite elec fans
Apexi Neo
Blitz boost controller
new cts, waterpump, radiator hoses, belts
optima redtop battery
boost is at 12lbs with fuel added by neo


What ive checked:
-pulled plugs on front two cylinders, cranked to check for spark (also
installed 2 new coilpacks, 4 new ngk iridium's)
-installed fuel pressure guage. 42psi pressure hot and cold
checked fuel lines for kinks, installed 300zx fuel filter
-checked tps, unplugged it.
-checked maf, cleaned and unplugged
-replaced coolant temp sensor
-replaced ecu with another stock ecu
-checked every fuse
-checked relays for melts
-checked all my grounds
-checked and tightened all couplers and exhaust bolts (o2 sensor as well)
-checked vacuum lines along intake mani
-checked all the battery cables for sloppiness

Its obviously some sort of heatsoak problem. Never shows itself when car is cold or just warmed up. I can turn the car on, shut the car off over and over again as long as its not warmed up awhile. If i let it warm up to operating temp for a while, its a rarity if it restarts.

I still have to check the timing. A friend is bringing his gun over.
Could this be caused by some sort of vvt sensor?

japanesenut

I would check the timing and recap the results, vtc can go out , from what i have heard though is it makes a lot of noise .

redd100

The timing seems to be 15*. It is running on the second mark from the right.
I'm beginning to think my car hates me!!
should i drop the timing down to 10-12* and see what it does?

japanesenut

15 btdc is ok ,Im leaning toward iacv have you adjusted it any if not then do so out is more air in is less if it helps then there's part of your problem .

redd100

Well i pulled the iacv off and cleaned it all out with carb cleaner, then reinstalled. I adjusted it in and out. Did not seem to really do much either way. I still have to pump the gas quite a while to attempt a hot restart.

I did notice a good amout of oil residue in the intake manifold.. The car isnt burning any oil because i keep checking it. havent had to add any. Could a plugged oil catch can (breather hole taped shut) cause oil to blow back into the intake manifold? The local shop i took my car to plugged it and i didnt notice for several days. The car hasnt been driven much except for testing.