180SX bad engine Issue - 1 day left - hopeful fix

[Demonvia]

Hey guys most of you would have probably seen me posting/asking around on other forums in regards to my 180sx's recent engine issue, Now i'm getting kinda desperateas i have pits on Thursday, if i can't make it then i will have to hand the plates in.


92 Nissan 180SX
SR20DET
T25 - stock boost
FMIC
Manual
Stock standard ECU



I'll start from the beginning just to be thorough.

The issue just randomly appeared one night as i was driving home, no warnings or anything.

What happens is that I am able to drive the car fine for about 10-15 minutes full throttle/full boost throughout all the gears.
then, once the engine gets nice and warm the engine will start to feel as if i'm hitting a wall and i can no longer rev past a certain point, think it may be around 3 -3.5k
revs. I can be planting my foot all the way down to the floor and the car will be jolting forwards as it is able to rev at random intervals almost as if i am stomping
the accelerator


As seen in this video i made recently - recommend to listen to it wearing headphones as my phone audio quality is quite bad.
Keep in mind that i am not backing off the accelerating i pretty much at full throttle most the time.

http://www.youtube.com/watch?v=o-Mp4AEvg90

heres one after the car had been sitting on idle for 10 minutes

http://www.youtube.com/watch?v=UBA6CX0tKQk

Things i have tried or checked

Checked CAS
Re-Timed using CAS
Could not hear or see any boost leaks
Checked Fuel lines for splits
Replaced Fuel pump
Replace Fuel Pressure Regulator
Replaced Fuel Filter - Check contents all fine
Replaced AFM x 3
Checked voltage from AFM plugs/wires - all Ok
Un-plugged O2 - still have issue
Re-plugged O2 - still have issue
Checked Sparks across coilpacks - all Ok
Checked temp sensors - all Ok
Replaced spark plugs with NGK's
Drained fuel and refilled with a fresh batch of 98
Tried swapping the fuel lines around (return ect...) just incase, No luck.
Wound the boost up 180 ran fine and was able to boost perfectly (all the way to the bar) that is, until it got warm and the issue came back again :(
Re-Tightened fmic hose clamps
A day at C-Red - still have the same issue.





I have yet to try another ECU as i am having trouble trying to find someone who would let me borrow one for the day (tomorrow).
I'm going to replace the ignitor module tomorrow.

Any ideas guys i'm open for pretty much anything at the moment, will greatly appreciate it. Happy to answer any questions.

[TJ]

Put a fuel pressure gauge on it and go for a drive.

Pump warms up, pressure falls. flows enough to drive it off boost on low rpm, load it up, cant deal with it. EXACTLY what my second RS did.

[Demonvia]

Put a fuel pressure gauge on it and go for a drive.

Pump warms up, pressure falls. flows enough to drive it off boost on low rpm, load it up, cant deal with it. EXACTLY what my second RS did.

hmm i see, so end result would mean (another) bad fuel pump?


The fuel pump whine is quite loud too, probably normal though

[joshg123]

My first thought would be to head in the direction of fuel pressure/flow

EDIT - Ie volt drop to pump etc etc or bad earth.

[Paulee18]

Ive heard of something similar but it ends up being the wastegate is screwed but saying that it was only when they hit boost pressure not at 3-3.5k hope you can figgue it out in time

[magic1]

Tow it to a workshop. Stop crying

[Buckets]

Tow it to a workshop. Stop crying

Spot on. If you can't figure it out yourself then give it to someone with the skills and tools to do it on your behalf. If you don't want to do that you clearly don't want to keep the car registered.

[Brett_J]

I'm going with fucked alternator/wiring.

[DISTRBD]

Checked temp sensors - all Ok

A day at C-Red - still have the same issue.


Change coolant temp sensor while you're at it



Tow it to a workshop. Stop crying

I believe C Red is a workshop ..

[peaknwa]

I think it is the ECU Nissan ECU are not the best in stock form. Im sure you could get a stock ecu quite cheap

[180SXTCY]

Did you replace the fuel pump with a new one or a second hand one? If second hand put a brand new one in there to me it sounds like a fuel starvation problem under load.

Also if you can swap the ecu out for another one.

[Skitzo]

Tow it to a workshop. Stop crying

LOL. LIke C-Red? That's twice now. Maybe you should lay off the heckling for a little while.

[Brett_J]

Voltage across coil packs might be ok, but once they heat up, if there is any chance of a hairline crack or problem, the heat will bring it out and you'll have them farting all over the show.
Also the fuel pump as mentioned, change it out for a new one and then run new wiring for it so it gets a constant 12v+, plenty of tutorials on the net for it.
Check the amps coming from the Alternator, it might be fucked, drop into an auto electricians and get them to chuck an ammeter on it to see what amps its pulling with a few things turned on like headlights,aircon and what not.
Swap the ECU over, plenty of people have spares floating about, its a 2 minute job with a 10mm spanner
Check all the earths properly, even go to the extent of hitting up Supercheap and getting some high amperage wire and run new earths to a few things.

[3sgte]

Ive had the exact same problem on a 3sgte, I had to re-wire fuel pumps with better ground.

[3sgte]

Rub some high temp silicon over your coil packs if you think they might be cracked. will solve the problem for a while

[Alt_F4]

Coils, & earthing would cause misfiring, not a hard cut (looks like that from video), lack of fuel would though.

Look at fuel pump wiring to start with.

[stumps.]

LOL. LIke C-Red? That's twice now. Maybe you should lay off the heckling for a little while.

I was going to say the exact same thing. This is a car forum aren't people allowed to ask for car help any more?

[Denver]

Cas or coils would be my guess. Or coolant temp sensor.

[johnnyrx7]

My 32 did this 2 days before powercruise.

15-20mins drive perfect, and then missfire and drive like a dog until cool down.

Swapped Ignitor, drove for 20mins same result.
Swapped coil packs even though they tested fine, problem solvered.

[ichi-go]

I think it's your coolant temp sensor, goes into limp mode when it doesn't have a reading

When you say check temp sensor, ok, is that checking the voltage or just have a look that it's still in one piece?

[Turbo2.6L]

Swap out coil packs as suggested. Heat causes the cracked rubber to expand & then interferes with the spark produced.
Use electrical tape to cover entire coilpack(s) for a short term solution, to rule them out if you don't have access to another set :D

[Demonvia]

Thanks for all the replies really do appreciate it.

If i had the money I would have sent it into a (another) workshop, money is probably the main obstacle at the moment since the issue could not have come at a better time being around the most expensive time of the year, Christmas.

I had someone over today to help me find out what could be the cause of the issue he used one of those diagnostic Computer's that you plug into the car, everything seemed fine besides the CAS. The CAS was always showing negative numbers even when we had retarded or advanced the timing. So will be picking one up tomorrow morning, hopefully can install and re-time the 180 (install whatever else i can get) before i head to the pits at the 11AM :P




Change coolant temp sensor while you're at it

Yeah, will pick one up at kyp tomorrow :)




Did you replace the fuel pump with a new one or a second hand one? If second hand put a brand new one in there to me it sounds like a fuel starvation problem under load.

Also if you can swap the ecu out for another one.

Replaced with a known working 2nd hand one a bosch 040, Once i get some more cash i'll have to invest in a new one


I think it's your coolant temp sensor, goes into limp mode when it doesn't have a reading

When you say check temp sensor, ok, is that checking the voltage or just have a look that it's still in one piece?

C-Red said it okay, unsure on what was done but as above i will replace it just so i know if it is or not


Swap out coil packs as suggested. Heat causes the cracked rubber to expand & then interferes with the spark produced.
Use electrical tape to cover entire coilpack(s) for a short term solution, to rule them out if you don't have access to another set :D

haha, took your advice on wrapping it with electrical tape, i did notice that there were a few cracks in them. Will find out tomorrow morning if it work or not don't wan't to piss the neighbors off too much lol.

[Demonvia]

Missed my appointment at the pits today, that shitty feel. Probably now have re-scheduled about 3 times now.

What i did earlier today,

- Replaced Coolant Temp Sensor
- Re-Timed
- Replaced the CAS
- Replaced the Ignitor Module
- inspected coilpacks again after driving - tape was all good still

Still have the same symptoms as before with no improvement.


Upon driving it around today i noticed that it was not revving as fast as it used to (before the issue) Also noticed that right after turning corners that it would show the cutting symptoms just after. Maybe thinking it is fuel :\ but unsure where to check as i have already replaced the Fuel pump and FPR

[stumps.]

wiring to the fuel pump as suggested? Shitty earth?

[wormbo2]

^^this.
New pump, same wiring = no fix.
Might be worth looking along the chassis for anything that may be earthing something out?
Had a similar choking and spluttering issue on a 3.8 v6 commodore, alternator wire was totally fucked out, causing earthing and spark problems etc.

Fixed it with tape... Lol

[alexinperth]

If you're near Midland, I can lend you a set of coilpacks to try.

If you can see cracks in them, then they are rooted. It's a really common problem.

[Faz]

Ive got a spare set of 26 splitfires if they can fit an sr by any chance?
come by on the weekend and i'll check amps from alternator and also look at pump earthing.

[Demonvia]

Cheers guys, I'll shoot one of you's a PM once i can organise some time to work on the 180

Pretty sure spitfires Will fit I may be wrong though

[Demonvia]

Update

Had a brief look around the fuel pump area last night found what looks to be a frayed wire however unsure on what it is supposed to be for since i ran out of light, When i get more time i'll try and follow it back to where it starts.
I'll post a pic of it incase someone somehow knows what it is/could be lol.

http://i.imgur.com/GZ5E8.jpg

There is also Red wire that looks like it has been cut.

[Faz]

google pinout and look for that colour combo?

[brynj]

You'd also want to at least tape up any of those exposed wires.
A quick google search says the blue/white wire could be the fuel sender unit wire, but results seem to vary. Does the fuel gauge work ok?

[Demonvia]

You'd also want to at least tape up any of those exposed wires.
A quick google search says the blue/white wire could be the fuel sender unit wire, but results seem to vary. Does the fuel gauge work ok?

Yeah the fuel gauge works perfectly probably the best one in a silvia i have had so far lol. Also found that the blue and green (not the white and blue) wire is for the AC relay's signal
shall cover them up nicely afterwards

ECU = 94-96 S14 Silvia SR20DET

[mys1]

I would have used silicone spray not electrical tape on the coil packs....

My bet is on coil packs - super common issue on a lot of older cars!

[Demonvia]

I would have used silicone spray not electrical tape on the coil packs....

My bet is on coil packs - super common issue on a lot of older cars!

Yeah will most likely borrow another set to be sure.


I'm using this as a reference
http://www.enginebasics.com/Misc%20Information/sr20det%20wiring%20diagram.html

So if i'm reading this right, from the cut wires i found so far (below)

Green White = 14 - CLK clock (timing signal) - don't know what that does, can't seem to find anything online

Blue white = 45 - Ambient air tamp sensor input - Blue White - useless

Red = 46 - ECCS backup power -??

?