One Prob After Another - this GTS-t doesn't like me!!!!

[krispenev]

I hate posting this type of s*** on here, but when you're stuck, you're stuck, and you guys on here have always helped me out. I have to appologize if this problem has been addressed somewhere, sometime ago, but it's like searching for a needle in a hay stack with all the post on NICO....not a bad thing usually, but not in my situation because I can not find anyone with this type of problem.

Problem:

1992 Nissan Skyline GTS-t (104kms or 65 miles)

She runs great, actually fantastic....but only in the first 10 minutes or when she is below normal temperature....then she behaves like a dog, a ***** actually. There's sputtering, back firing, terrible fuel economy, stinks of gas, and worst of all, it sounds like the RB is running on 5 cylinders, the kind of noise I would expect from an overly priced Subaru. Anyways....

At first, I thought it was the coil(s) or the fishy looking harness and all its semi broken clips.....and so I replaced the coils and the harness. Nothing. I ran the steps for an ecu diagnostic thinking the ecu had some sort of problem under normal temp conditions....but no error codes, for ANYTHING!

The funny thing is, I dont drive this car alot, and especially not far due to this problem. When I go to my gf house (10 minutes away) it'll start doing it at the end of my trip. When I go to leave a couple of hours later.....everything will be great.....until I reach my house.....and it has starting ****ing around again.

If anyone has any ideas, give me a shout

[audtatious]

If you smell gas, have you checked the injectors?

[krispenev]

Do you think one of the injectors in not flowing properly??? How would I test an injector...I have never done it before???

[krispenev]

Anyone else have any ideas???

[ScrapMetal]

You have to take them to a shop so they can pressure test them.

[Gold Digger]

If you are leaking fuel from your injectors it's pretty noticible. Just look down where the injectors are and see if there is any pooled fuel down there.

Or you could just take a lighter and wait for an explosion.....I'M JUST KIDDING...lol

As far as it running like dog **** after start up, mine does it to in my Laurel, but only for about 5 minutes. And the RB isn't a great milage car in the city. I get almost 400KM on a tank when I do a lot of highway traveling, and nearly 300 if it's just city.

[krispenev]

There's no fuel leaking from the injectors. I just took a flash light to it, and didnt see a thing....Could it be a stupid plug.....I just put new ones in 5000 kms ago...

[boostin13b]

what heat range of plugs do you have installed? I have run into problems in colder climates with colder plugs. Usually the more boost you run or the more mods the colder you want, but if it's winter, you may want to step it up a range or two hotter, they won't foul as fast which sounds like is happening. I have the same problem with my wifes built SR in cold climates on cold start as well as a few customer cars. You may be running 7's or 8's in there now. I belive stock plugs for RB's are supposed to be 6's. But if you don't run it hard and don't have the boost at a minimum you can probably get away with some 5's to get you through the cold months, but it's not recommended for turbo cars to run that heat range hard.

If you are getting new plugs, try some NGK iridiums, they won't foul half as fast as platinum or standard, I've had very good luck with them in all my cars I build.

[krispenev]

Thats what I got.....NGK Iridiums gapped at 1.1mm....the most expensive plugs at your local auto store.....and they are new....thats why this problem boggles me...i don't know the heat range though...

[Zadkiel]

maybe they need regapped? I know, to run properly, my SR20's plugs need to be gapped at .025. What was the gap at when you first tuned the vehicle?

[boostin13b]

The gap shouldn't matter so much just driving and idling. You have to gap down plugs down to keep from blowing out spark at higher boost levels. If you are having a weak spark problem at idle and such, you could have a weak engine ground causing poor sparking conditions. To check this, just grab some 8 gauge wire, like you would used for small amp installs, and bolt one end to your head, and the other to a clean paint free body ground like a strut nut or something. Do this before you start it cold, then see if you see a difference in running, if you don't, then you can rule out that senario. I would lean towards the plug temp, I've run into this plenty of times in all makes and models of cars, including RB's, SR's, B-series. Mainly turbo cars because of their lower compression numbers. N/A cars are as effected because they used hotter plugs to begin with.

[krispenev]

aight cool, I;ll have to roll up my sleeves here again, and see whats going on with these plugs. thanks

[dj_hype]

I run BKR7EIX plugs in my car (0.8mm gap I believe) and they run extremely well. I used to have a problem with the NGK BKR7E-11's where I would get a high RPM miss (at stock boost). Upped the boost to 11psi and it only got worse. Swapped plugs, haven't had a problem since.

But your problem that you originally described sounds like a problem I had with my old car. While it was cold, it would run great. But once it warmed up, ran like crap and got crap gas mileage. Turned out the plug for the water temp sensor that goes to the ECU was unplugged. Plugged it back in and was set. But this was on a completely different brand of car.

[97katurbosilvia]

one more thing to look at is the coolant temp sensor which when you say it runs fine at first but after 10 min or warming up it runs like **** is what i thought of. I have done several sr swaps and 2 of them had this problem they run great for 5 min-10min then pretty much stall. try the coolant temp sensor as this affects the way the computer controls the fuel in the time frame you speak of. good luck

[krispenev]

Thanks for the help guys, but if the coolant or water temp sensors are acting up, wouldn't the ecu flash those codes at me when I do the diagnostic? I just ran it again today, and I got code 54 ( AUTO SIGNAL to ECU) code? WTF. That should be an error code if the automatic transmission wasn't communicating with the ecu properly....but hello.....the car is 5 spd, and none of the E-HCR32 (type M's) came in automatic. HMMM???? This doesnt make any sense.

[kev-bo]

ok first gap your plugs to .8mm then check the little box that your coil packs clip into and see if they all run at the same voltage. if that dosent fix it you could try going to a single coil pack thats what i did and now my car runs awasome um if that stuff dont work let me know i got more ideas just no motovation to type right now

[boostin13b]

The coolant temp sensor sounds like a very good possibility. There may be 2 of them, on for the gauge and one for the ecm. I'm not sure if there are on RB's. SR's there are and I've seen numorous problems with them. Even just a poor connection with the harness at the plug.

[krispenev]

I think it is the coolant temp sensor...I dont know if the RB has two sensors, that would be good to know if someone has that info. If there is two...my temp gauge works correctly...so it must be the other one (if there is two) not sure?!?!?! By the way...I cant find this sensor anywhere...anyone have ideas where I can get this part...part number would be awesome too

[krispenev]

Im running the car at stock boost for now until I get this issue resolved, but I was told that the RB20 should run on 1.1 mm gapped plugs. Am I wrong or what? As for the coils and the ECM....volts are good, and I changed all the coils...no change...still the same problem. The car warms up to reg temp...and all of the sudden starts stuttering. Sounds like a mis-fire actually. Where would I get the coolant temp sensor, alot of people have told me that it is most likely the culprit. Give me a shout...and post your gts-t pic in my other thread. thanks.

[boostin13b]

More often than not, it's just the wiring or the plug to the sensor, but I have had to replace a couple sensors in the past. They are usually located on a water outlet pipe comming off the head or block. Just look for a sensor that screws directly into one of your aluminium pipes for coolant, like a radiator hose.