Chris_Guthrie

Both of those things are on my to do but not quite in a position to do that just yet until I can at least get it running back to stock. Going to work on getting the exhaust manifold gasket and studs replaced first, an obvious need it now. Then I'll try out the new maf and see hownthat does. After that I'm thinking cas if I'm still having the same issues. Still need to run the fuel out and refuel I'll change the fuel filter tomorrow along with cleaning the iacv with carb cleaner. If all else fails I'm going to get a serial port and see if I can get some sort of data on what the ecu is seeing when the issue is happening but really hoping one of the methods above work out first. After I get a good base I'm going link but have to save for that so it'll be a while for that based on my tuners suggestions. Definitely need the exhaust leak fixed first though car has always fallen flat after about 4-4500 rpm since I've had it and suspecting that's the issue. Then I can move forward with the rest.

I'm thinking this but when I checked the fuel tank the fuel strainer under the pump was as clean as new. I do have a new fuel filter I'm going to replace that hose and filter just to be safe because maybe something did get through the strainer but I'm also going to attempt at some point next weekend to get the remaining fuel out and fill it up with some high quality fuel.

Just got back from a quick test and I'm really thinking that maybe the fuel line is sucking air in. I noticed when I removed the fuel pressure tester the hose on the fuel filter was easily spin-able. When it was twisting I noticed a slight change in the engine rhythm. Took it out to see and did fine again without boost and for the most part did fine in boost until I got a big hiccup about half throttle going up a hill. Going to investigate that further when I get more time. Probably just replace the fuel filter and the hose and see if there is any changes. Was able to go about 10m away today with the car feeling fine, actually felt a little stronger im guessing thats the splitfire coils (still an intermittent misfire at idle). That's good to know at least. Guess I can rule out the pump. Also thinking could be bad fuel though I filled up my bike (11' R1) at the same place the other day with the same 93 octane and got a crazy misfire that I never had on that before too.

Fuel pressure increases to about 48 when blipping the throttle while running

Latest update, reinstalled the evap canister. No change. Disconnected the fpr vacuum hose, no change. Hooked up the fuel pressure tester. 42psi when primed, consistent with what I've been seeing online. When running, drops to 34psi. Ideas on this? Also, when I did my fuel pump rewire, I tested hot before tapping. I attempted at first to just unplug my relay to relieve fuel pressure and the pump still primed and ran. Thought that was strange. Unplugged the connector in the trunk by the fuel hat and was able to relieve fuel pressure that way. Starting to wonder if I jacked something up with my wiring because shouldn't be priming without the relay hooked up.

That's good to hear I'll stick with the stock I hear they are good for 500hp and I'm only shooting for 350-400 once I can get this thing sorted and get to actually building it.

Any recommendations on a decent replacement manifold that doesnt break the bank or require additional mods for the stock turbo setup? I figure if I'm going to pull the manifold off anyway to fix the studs might as well replace it.

So I checked the turbo out today. Very minimum play at all just enough for the oil to take up when it's running. I did find an exhaust leak at the manifold. 1 stud all the way in the front is missing and the one all the way in the back is broken off. Front has visible signs of an exhaust leak. I'll fix that soon but that's not my problem still. I also found that the nipple coming off the turbo had the hose capped off and a hose ran from the j-pipe by the bov going to the wastegate. I removed that hose and capped that nipple and put the turbo nipple hose back on the wastegate. There was a ton of oil residue all through the charge side of the intercooler piping going to the throttle bodg. I'm thinking that's from the pcv. Doesn't seem to be coming from the turbo that was all clean on the pipes side. Haven't had a chance to check fuel pressure yet, haven't had time been having to pull a lot of doubles at work. I did pick up some carb cleaner to clean the iacv but wanted to make sure I had a fresh gasket in case the old one rips when I pull it off. I'm waiting on a MAF that was supposed to be here today but delayed to Monday. Have a double Monday and Friday and work all of next weekend so going to try to find some time in the middle of the week to try that out. Did about a 10m trip around the block today and towards the end the issues were coming back. Fingers crossed on this MAF but if not just going to throw a fuel pressure gauge in and see where I'm at. Did notice today that I can definitely hear the injectors pulsing. Very audible clicking coming from them. Assuming that's normal? Should also mean CAS is functioning somewhat properly. After it warmed up when I started it the intermittent misfires came in again. Did start doing that before it was fully warmed up.

Well considering I have the exact same problem with that as the original one I don't think that the ignitor is the problem. I would imagine that this being such an uncommon problem the possibility of getting a new ignitor that is bad in the same way as the old one has to be very slim. I'll definitely pull everything apart this weekend and check the turbo out. Got quite a bit of things to check out Saturday like fuel pressure and the pcv so I'll report back once I do that. Thanks everyone for all the replies this is all really helpful

I'll rent a fuel pressure tester soon and report back.

It has a separate fused 10ga wire running from the battery to the relay in the trunk. 10ga on the ground also.

Actually I did the fuel pump rewire 2 days after the issues started. Grinded away the paint and grounded it to the chassis behind the right panel in the trunk.

I do think it's weird I had it for 2 weeks then the issue came up out of nowhere and progressively got worse. I would've imagined changing everything in the ignition system would've resolved any ignition related misfires but still has the high rpm and idle misfires that seem unchanged. I would've thought if it was fuel related it would happen all the time unless it's the pump losing pressure when it gets hot. If it was the ecu I would think it would do it all of the time. Something I noticed when I had it all apart was a pretty decent coating of oil in the J pipe coming from the throttle body. The weird thing about that is the pcv that goes to the intake is blocked off. So that has me wondering if the oil is coming from the turbo because that's the only thing that could get oil in there. This thing does sound like it spools like a mofo like I'm a former dsm guy and the only stock turbo I've ever heard spool this loud (to only go up to about 5psi) is on a diesel truck. And the recirculated bov is really loud too I had a TurboXS RFL and this thing is just as loud and being so low on psi seems a little weird. I don't know if any of this is or isn't related but just trying to make sure I'm not leaving any potentially helpful information out.

So latest update. I replaced the ignitor with a jspec unit from enjuku. It felt a lot better at first although it is a little bit cooler of a day than it has been. Warming up didn't have as much misfire sputtering as before. Went on a 10m test drive. Felt good, a lot stronger though I was taking it easy on the boost. On the return trip started getting the cutting out at higher rpm again and was getting worse the longer I was driving. Took it easy the rest of the way home. Before turning the car off was getting the normal idle sputtering I was getting before. So where I'm at now, entire ignition system has been replaced with upgraded components. Plugs still gapped at .8mm. Removed the fuel cap in case it was building too much reverse pressure I'm the tank, didn't help at all. Now I'm still on the same tank of gas the fuel treatment was in, I'm thinking if I can run that out and then refill with fresh 93 maybe the treatment is too concentrated in some areas but doesn't explain that it only does it once the car is warm. I'm leaning towards fuel pump or injectors but if the injector was clogging I don't think it would make it shut off like it has but then fire right back up like nothing happened. So my current guess would be the pump. Without a fuel pressure guage no way to test or check it while it's running. So that's kind of where I'm at. Need to start testing fuel components and ecu/wiring but I'm at a loss of what's the next logical step and procedure for testing it.

Facts but it's okay I've ordered a new ignitor based on GTSBoy's confidence. In the meantime I did the ole jiggle tap on the maf connector with no change. Seems like the warmer it gets outside the worse the issues get. Hoping it's the ignitor. Also going to pick up some carb cleaner and try to get that iacv cleaned out real good. I'll report back once I've gathered more data. I really appreciate the feedback though guys keep it coming. Trying to learn everything I can about this car want to keep this thing for a long time.

It won't know it's misfiring but I'm thinking if I can compare the values of things like tps and maf then at least I can rule them out if they are within range when it's acting up. That speedo cable sounds like a bit of a drag. But hey, worth a try to see if I can fix it. Going to focus more on the stalling issue for now and come back to that once that part is sorted. Thank again for all of your help!

Also forgot to mention this but I've also noticed that my speedo doesn't move smoothly like normal and it's only sometimes but it's kind of Skippy, up, down, up a lot, down a little. Not sure if that makes a difference but thought I'd mention it just in case.

Thanks guys that gives me at least a place to start tomorrow. I was debating on the consult cable but that solidifies it for me. Ran the ecu diagnostic and got a 55 figured nothing stored should mean okay but would really like to see the inputs when the issue is happening. I'll get that fuel Guage asap and will probably order an igniter but want to give it a check cold and hot to see if there's any difference. I really appreciate the quick replies and experience fellas

Hey guys, 1990 R32 GTS-T sedan with the RB20DET in it. Mostly stock, has an apexi air filter, ti catback, coilovers and wheels. ~67k miles Just bought this about a month ago. The past 2 weeks I've been having some issues. On cold start ups, there's a bit of a hanging idle at around 1700rpm. Once it warms up a little it drops to a normal idle. When I drive the car and come to a stop light, the idle hangs for a little while then returns to normal. On idle I have an intermittent misfire. Cold, hot, doesn't matter. Unrhythmatic. Go out for a drive and until the engine is warmed up it drives perfectly fine. Hits boost fine, feels strong fir a mostly stock car. Once warm, under a load especially when hitting boost there's a heavy misfire, feels a lot like spark blowout but it's as if the car is cutting off. Eventually, it gets worse and worse until the engine completely cuts off. First time it happened, it bump started itself before I stopped. Got home fine no issues (about 8m). 2nd time it happened, came to a complete stop, turned the key off, primed the pump, started up fine made it home fine (about 5m). So, investigation commenced. So far, I started with putting some BG 44K in the fuel. That didn't help at all so I started by replacing the spark plugs with the same NGK BCPR6ES gapped at .8mm. I've installed slpitfire coils and a wiring specialties coil harness. I popped the fuel sender up and checked the tank for rust, very minimal if any. The fuel filter was brand new when I got the car. Cleaned the MAF with MAF cleaner. In the US and run the highest octane available to me - 93. I've done a ton of research in the last 2 weeks and sort of narrowed it down to a few things. The problem is I'm having a difficult time finding clear information on how to test these things. The list of things I have left are 1- MAF 2- Ignitor/ ignition control module 3- fuel pump losing pressure when hot (happens at all levels of fuel in the tank) 4- fuel pressure regulator 5- TPS 6- CAS 7- fuel injectors 8- ECU 9- Turbo - maybe blown? I'm new to RBs, skylines in general. Really been enjoying driving this car when I can. I'm pretty good with most things automotive. Any help much appreciated. Keep in mind I don't know a single other R chassis owner or have access to known good parts to test... and I'm broke so there's that but I'm handy with a multimeter and pretty much everything but soldering. Thanks guys