RyoFC3S

iTrader: (1)

Hey,

Before I begin, I just want to make it clear that I have searched A LOT. I have found similar threads with similar problems, and I've tried their solutions with no results. This is probably going to be pretty difficult to diagnose, but I'm hoping some of the more experienced members can offer some advice. I'm kind of shooting at multiple targets, and I'm pretty sure they're not all caused by the same thing.

The car: 1990 (S5) TII. Moderatly/Heavily modified. I have mods listed in the links in my signature. I believe 95% of my emissions are removed (everything that is unnecessary is gone).

Here's the problem(s) in a nutshell:

1. Starting

Cold start is absolutely terrible. I've uploaded a video to YouTube to give you an idea. The colder it is, the worse the start. It's been like this for a long time, I want to say probably at least a year, and probably less than 10,000 miles.

When its REALLY cold (like in the video) when it first starts it makes this weird whining sound. You should hear it in the first 20 seconds or so, but it goes away after the first few start attempts. It was below freezing when this video was taken.

Also, the only way to get it to start ANY time (hot or cold start) I have to go through this process to start it: crank once, stop. crank again, blip the throttle to give it some gas, stop. hold foot to ground for flood clear, crank it, then it starts fine. Its really really annoying, but its the only way to get it to start. You'll see this in the video. It WILL NOT start without flood clear, period.

Once it starts (cold) it will rev up okay, then suddenly die. It will do this over and over again until the engine warms up just the slightest bit. After the video ends, I had to keep doing this process for another 1-2 minutes straight.

The video should give you a good idea of what I'm talking about with all of this. In the video, I'm either giving it NO gas or WOT (100%)

http://www.youtube.com/watch?v=QG1Ko2JoyEc

2. SAFC problems?

Okay, this is really weird and its been happening for a while. I can't say exactly when, but for a long time it WAS NOT like this. It worked perfectly normal.

Just watch the throttle (Thr) signal on the SAFC. I'm either giving it no gas(0%), a constant throttle (like 65% just to keep it at 3000ish rpm) or WOT (100%). I am most definitely not tapping the pedal at all like the video suggests.

http://www.youtube.com/watch?v=LPc1GiwIUwk

3. Fuel Cut?

At roughly 4600-5200 RPMS under WOT, I hit this really weird fuel cut or misfire. It revs fine, but all the sudden it falls on its face, through that range, then picks up fine afterward. The reason its weird is no matter what I do to the SAFC, it doesn't seem to effect this at all.

I had it recently dyno tuned (summer) and it ran pretty well. No significant burps or anything, ran pretty solid. Now that its winter, it runs terrible, worst at that 4600-5200 range. It bucks at what seems like random RPMs across the range. It almost seems like roughly every two seconds it momentarily falls into limp mode, then returns back to normal. The 4600-5200 range is much worse than the other bucking at other RPMs.

I'll add more information soon, I have to go.

Here's information that you should find useful:

1. Items I have recently replaced or changed:
- Oil and Oil Filter (days ago)
- Plugs (days ago)
- Plug Wires (5000 or so miles ago)
2. Items that have been tested/adjusted to specification:
- TPS
- AFM
Note: I got used items for each of these. When adjusted to spec, there is no noticeable difference when the "new" TPS/AFM is installed compared to the old onces I used to run.
3. It was dyno tuned recently (summer) and ran decent. Except, there were these random pitfalls where the power would suddenly disappear, then come back. On the A/F Ratio graph, it showed up as a literal break in the line. The line stopped, jumped forward, then started again. If you want to see this I can upload a scan of the dyno sheet.
4. The car has a pretty aggressive streetport. I understand that with the porting and with the lack of idle control, it should not idle well. Except, it actually used to idle REALLY well at about 800rpms. I have not added any upgrades or taken off any more equipment since it ran really well, the idle just got crappy one day.
5. I doubt this has any affect on the problems, but I have a kind of nasty exhaust leak where the manifold connects to the engine. The stainless steel manifold is warped, I am in the process of buying a new cast iron one. Because of the leak and lack of heat shielding, the wiring harness is pretty beat up.
6. Wiring harness: In kind of bad shape. Its been hacked and slashed, taken out several times, and is the original one from 1990. It suffered through a severely overheated engine, and my mechanic who has done a TON of work on my car wants me to get a new one. I have a megasquirt EMS installed, but turned off. All connections are soldered at LEAST, if not heat shrinked.

I'm sure theres more I'm forgetting, but this will have to do for now. I have to go, I will pick up later. If you have any questions, fire away.

THANK YOU FOR YOUR HELP. Any help with any of the questions is greatly appreciated, you don't have to answer all of them if you can't. I need this car to be running before I leave for college again (end of January), its my only way out there.

RyoFC3S

iTrader: (1)

Short edit:

1. Forgot to mention the compression is fine. I didn't do an actual test with a meter, but based on the sound/feel of the air coming out of the housings, the compression is perfect. The engine also has less than 15,000 miles on it, with all seals, springs, etc replaced brand new.

2. I have NOT done a vacuum leak test yet, I am working on that, will do in the next couple days. My mechanic tested it a few months ago and said there were no major leaks (maybe 1 or 2 extremely minor leaks), but maybe its changed since then (that may explain it getting worse).

3. I also forgot to mention that I JUST replaced my starter a few days ago, and my battery tested out fine too (its pretty new as well).

4. Oh yeah.. I mentioned that I just replaced my plugs. I keep fouling plugs over and over again, they're not seeming to last more than 3000 miles. Every time I pull them they're usually soaked in gas. I've also heard from friends that I leave a lot of black and blue smoke when I floor it and when I let off the throttle. Its obviously running really rich, but changing the AFC settings doesn't seem to have a major effect. The bucking/cutting out problem is so bad that its hard to tell what my AFC is doing, but I can say that without a wideband it seems like the affect my AFC has on the bucking/cutting out is minor if any.

5. My fuel injectors were tested recently. They are not leaking and are well within spec in all electrical readings. They are also very new, all Denso injectors, with less than 20,000 miles on any of the 4.

Thanks again for any help you can provide with any of my questions!

arghx

iTrader: (3)

I think you have a couple bad sensors and some general electrical gremlins.

Some may feel this is not necessary, but you need to replace your water temperature sensor, the one on the back of the water pump housing. It's like 30 bucks if you go OEM, or 10 if you go to autozone. It's difficult to test it precisely even though there is a voltage spec in the FSM so you might as well just replace it.

I only knew mine was bad because it read too cold on my Power FC. Too cold because over time the sensor had developed higher resistance. an inaccurate thermosensor will make your car run poorly. If your sensor is completely bad the ECU will go into failure mode, but if it's just inaccurate like mine was it will run like crap.

Do you have an adjustable FPR? What is your fuel pressure set to?

Zero out your SAFC, but write down all the settings so you can put it back later. And who installed your SAFC? Is it hooked to the narrow range TPS wire or the full range TPS wire? Double check that. But if you ask me, you likely have a bad TPS. What you need to do is go to the ETC --> Sensor Check on the SAFC and read the TPS voltage as you are driving. If it's fluctuating a ton then you probably have bad sensor. It's hard to detect that with a typical multimeter and the car off. In fact, post your SAFC settings. The high and low throttle maps.

You need to get a wideband on that car, but buy a decent one like Innovate, PLX, whatever. Don't get the AEM UEGO if you plan to hook it to a standalone because it has a notoriously unstable signal with any ECU except the AEM EMS. Now why do you have the SAFC leaned out 30% in crusing? You realize the ECU is just going to ignore that under closed loop? Trust me, if you get a wideband and start playing around with the SAFC you'll get an idea of what the SAFC is good for (WOT to an extent) and not good for (leaning out for cruising).

What megasquirt are you using/planning to use? Did you make a harness adapter? What exactly have you done to your engine harness? It sounds like it is competely trashed to me. Hacked up to bits. You need to build your own harness or buy an unmolested stock one and make a plug & play adapter for the Megasquirt. Or at least buy an s5 patch harness from Banzai Racing and do all your SAFC wiring to that.

For a vacuum leak/boost leak tester, buy this http://www.boostpro.net/prodtester.html or fabricate your own. You can use a cheapo air compressor with a tire valve thingie if you have to. It is the best tool for finding vacuum and boost leaks. Pressurize the car and then spray soapy water all over to pinpoint the leaks. remove your stock intercooler and replace it with some plumbing pipe for the test.


EDIT: Until I went back and read through your mod page I thought you had like 550/720 and a BNR stage 1 or something. honestly... you need to give up on getting the car running right on stock ECU. You have too many fuel mods for it. You can't just get all the driveability bugs worked out on the stock ECU and then take it to the tuner so you can pop in the megasquirt. You need to integrate tuning into the process of making the car driveable. So learn how to tune it yourself or get the tuner over there to help you set up your injectors, TPS, cold start settings, etc.

I can tell you right now that all your sensors better be perfect (and configured perfectly in the megadquirt) and you better have zero vacuum leaks or the car will never run right beyond perhaps a WOT pull.

RyoFC3S

iTrader: (1)

You're probably right. Do you think the best idea would be to just spend the money to get a new/lightly used wiring harness?

I can do this, but would it be better to just get a whole new harness? That sensor on the back of the pump has given me problems for years, the clip is broken so I constantly have to push it back on. If the line is disconnected completely (which is very possible), will it ALWAYS run like crap or will it be off and on like I described?

I don't have an after market one, no. As far as I know its totally stock with stock pressure settings.

Just to see if it has any affect? I'll do this, I'm just curious what your line of thinking is.

My mechanic did, he's installed dozens of SAFC's on FC's.

How do I check that? Do you know what color the wires are?

You may be right, but its interesting there is no difference with either TPS's. Maybe they're both bad, since I bought the second one used also.

Do this before or after zeroing out the current settings?

RPM..........Lo Thr........Hi Thr
1000.....-17%.....-5%
1600.....-5%.....-12%
2400.....-5%.....-18%
3200.....-5%.....-33%
4600.....-25%.....-47%
5600.....-25%.....-45%
6400.....-25%.....-38%
6600.....-25%.....-42%
7200.....-25%.....-36%
7400.....-25%.....-40%
7600.....-25%.....-40%
7800.....-25%.....-41%

I also attached a dyno graph. This shows my A/F ratios. This map is 1 pull before I put in the settings you see above. I changed the percentages 1-2% from the dyno chart at the dips/rises in order to smooth the curve out, but you get the idea.

I actually do own an Innovative LC-1 unit. Its really really hard to use to tune though because there is no RPM signal that goes to the laptop, so whoever is tuning has to literally be watching both the tach and the AFR on the laptor at the same time. Is there a way to get throttle signal on the laptop via the LC-1?

Its leaned out like that because thats what it used to be dyno-tuned at (A/F ratio was best at -30%). I also had my stock O2 sensor plugged in, but just sitting in my engine bay reading constantly lean when these settings were made. I had the wideband in the O2 sensor bung. I was told the effect the stock O2 sensor has is negligible in changing A/F ratios. All I would have to do is run the AFC slightly leaner than I would have to if it was installed, because it would be telling the engine its leaner than it really is.

Like I said earlier, its really hard to tune with the wideband and an AFC with no throttle reading or way to data log/graph the RPM & Wideband readings at the same time. Also, the LC-1 seems to read pretty jumpy, like it bounces around and the needle moves really fast-- this may be because the laptop I use to tune it is really old (400mHz processor, 256 RAM) and it simply can't keep up.

To be honest, purchasing the megasquirt was a hasty decision. I'm usually very cautious and do a ton of research on this, but I sort of got talked into buying it and dug myself into something deeper than I could handle, and now I'm in over my head.

I honestly don't know much about it at all, and I'm working on selling it. I believe it is the Megasquirt-I version (older version). I believe it is the V2.2 main board. If pictures would help, I can get some. I bought the unit from a member on this forum, it can pre-assembled--all I had to do was wire the connections to the appropriate ECU wires (thats what he told me to do). I know for sure I connected the right wires coming out of the MS unit into the right wires going into the ECU. Like I said, the unit is turned off and unplugged.

If that is what I think it is, no, I didn't.

At the very least it has these things done to it: MegaSquirt tapped into lines running into ECU (turned off), Apexi SITC tapped into lines running into ECU (turned off), Apexi SAFC-II wired into lines running into ECU, Innovative LC-1 tapped into lines running into ECU (turned off/unplugged), injector harness messed with (installed resistor packs and S4 injector connectors) so I could use low impedance injectors. At one point my harness melted partially to my turbo, but I ripped it open and repaired all the lines and re-wrapped them with heat shrink. Also, my electric OMP is still connected but is just sitting in my engine bay hidden in a corner (so the ECU doesn't go into limp mode)-- there is a blockoff plate over the old spot, I premix now.

I bought the SITC to take care of ignition control since the version of megasquirt I have doesen't do timing. But, since the mega squirt isn't turned on, I don't use it.

Like I said, I'm going to try and sell the megasquirt. Eventually (sooner rather than later) I want to get a Haltech E6X or something similar.

I'm not familiar with this, I'll look into it.

Yeah, I'm familiar with this, I've done it before. I will be sure to let you know how this goes. Also, as you probably read later, I don't have a stock intercooler anymore--is that a problem?


[/quote]Until I went back and read through your mod page I thought you had like 550/720 and a BNR stage 1 or something[/quote]720/1600, Turbonetics TS04, actually.

It is possible though (I think). Like I said, at once point it was running really smoothly with the exact same mods it has right now. But, if you think it would be cheaper to get a full standalone, then I may just do that. This car is probably more than I can handle financially right now.

Is it possible to get it at least running smoothly using an SAFC and LC-1, if I get all the electrical gremlins worked out?

Unfortunately, my good friend and tuner just got offered a dream job out in Texas. He was helping me sort this whole mess out, but now that he's gone I'm pretty stumped. He taught me pretty much everything I know about my car; he's been working on rotaries for over 20 years, and upgrading them for 15. Now that he's gone, I don't think I have any choice but to ditch the megasquirt and go back to basics until I can afford full standalone.

You're right. In conclusion, do you think my best bet is just to toss out the old wiring harness and drop a new one in, then re-wire my SAFC, wideband, and fuel injectors?

Thanks a lot for your help, I really appreciate the investment.

arghx

iTrader: (3)

I'm going to write a lot here, so I'll open by saying that based on my experiences I am going to recommend you make a decision on your engine management system first and foremost. This decision should be based on the amount of local support for that system including both tuning and installation. No matter what system you choose, you need a good condition harness (doesn't have to be brand new IMO) and good condition sensors (preferably brand new but use best judgment) if you can afford them.

First I'll say that I used to run a Zeal Engineering Plug and play megasquirt on my nonturbo (different car than my turbo which I will discuss in a bit) but I had some trouble with it, admittedly due to my lack of experience but also because I feel the amount of support for the Megasquirt is limited. I took it to a shop and they never got it running right as far as driveability is concerned, although it made good power under WOT. I had a bad experience with the megasquirt overall, but there are plenty of people who swear by it so don't think I'm knocking it. My biggest problem was that I had no support for it locally, which now seems to be your situation because your friend can't help you out anymore. Also I seemed to get a lot of electrical noise which threw off my sensor readings. Yet my harness was in decent shape. I suspect the Megasquirt was overly susceptible to electrical noise.

Alright so that was my nonturbo and my experience with Megasquirt, for what it's worth. Now let me tell you what I did with my current Turbo II ('88) and you make your own decision about what to do next. I was in a somewhat similar situation as you. I had an s4 TII with an SAFC and a stock turbo, and I wanted to go to a full T04S upgrade. My stock harness was hacked up from previous owners and my own ghetto wiring jobs when I didn't know what I was doing. I had multiple bad sensors. I had multiple vacuum leaks (which I'm actually fixing right now).

I ended up going with a used, relatively unmodified factory engine harness. In hindsight if I had waited I could have found another one in even better condition, but I do not regret ditching my original one. I actually bought an 87 harness which has a resistor pack, so I didn't even have to wire in resistors or injector clips for my 720/1680 setup. I think you need another harness. If you decide to go for a plug and play system like the Power FC then get an UNMODIFIED s5 TII harness. DO NOT trust somebody else's installation of any resistors, injector clips, ground wires, anything. I'm not perfect at soldering connections but I've seen some ghetto **** in my day. Don't trust others' wiring (unless it is a reputable shop, not someone off the forums), trust yourself. Remember again that the Haltech has it's own harness (Microtech I think is similar but not as sure) so you can ditch the OEM stuff.

If you can't find TRUSTWORTHY (not the type of douchebags who screwed me on my nonturbo) local support for the Megasquirt, ditch it. You need someone to go to if you can't figure stuff out. There is not enough support IMO for Megasquirt online that you can easily figure it out (although many will disagree with me and I understand that and respect that opinion). I found the help files and tuning guides not thorough enough for our cars. The greatest support for our specific cars is I believe the Haltech. If you go Haltech, you can replace your harness and sensor (I believe) so if everything is installed correctly you know that will be bulletproof. But LOTS of people screw up Haltech installs. I don't know much about Microtech, but I know that people screw up Microtech installs too. So if you don't have local support for them either (is your car in LA or Denver?), you may find yourself in my position.

There is nobody near my home town of Raleigh NC that I trust could to mess with both a rotary and Haltech or Microtech (and definately no Megasquirt shops besides that sketchy one). So I ended up going with the Banzai Racing Power FC setup because of the relatively Plug and Play installation. I also have experience tuning it on my friend's FD, so I was up for the challenge. I ultimately replaced all my engine sensors (you have the replace the MAP and IAT anyway, and then my thermosensor and TPS were bad) with brand new ones and my harness with a better condition used one. Once again though use your best judgment on these purchasing decisions but remember that if you half *** engine management you will never fully enjoy your car.

If we had local Haltech support I would have probably gone with it, but without that suport who would I go to if I screwed up the installation? Haltechs are good units from what I have heard but lots of people mess up the install. Right now I am in the process of tuning the Power FC myself with the help of Power FC forums (although they mostly focus on FD's). I would think in a place like LA (is that where you live?) you could find somebody (Racing Beat? Mazdatrix? etc) who could tune something on your car (any of those major systems although I'm not sure about Megasquirt. Steve Kan specifically told me he would not tune it) and you won't be stuck in my position.

So to summarize my thoughts on engine management, figure out what has the best support in your area like I said. If you have no local support I would recommend the Power FC because I have had good experience with Banzai Racing so far in terms of their service (and you could also look for the similar AP Engineering unit) . But no matter what you do, budget at least $1000 for engine management and tuning. The cost of a harness and sensors (whichever ones you replace) are just going to depend on what kind of deals you can find and how patient you are.

As far as the fuel pressure regulator goes, well I'm not sure if the stock one will do the job. It probably will. By using the stock ECU though you have no way to lean out your maps for driveability, given that you will be running higher pressure with that pump. Also you will never get your injector transition as smooth as it should be on the stock ECU. It just won't happen, not with those injectors. That's why I say it will never be "driveable", and by this I mean close to optimum driveability beyond just WOT situations (idle, cruise, cold start, etc). For instance, all that plug fouling will probably continue until you have a properly set up standalone.


Finally, all that stuff about the SAFC I was telling you is just because if you do too much correction the computer will either ignore it or in some cases get confused and drive funny. I personally think a car on stock ECU with upgraded primaries will never run right, but you (and some others) may disagree. So I'd hate to see you waste a lot of time on this. Get another ECU and make sure you understand how it works, whether you personally tune it or not. Even if you lean the crap out of the SAFC map you will still have problems at the injector transition point, which good standalones can easily handle.

Hope that helps... sorry for writing so much.

jreynish

iTrader: (2)

I have the same problem going on exact same as your video but runs 100% when warm, starts fine and everything. Have you had any luck with this?

RyoFC3S

iTrader: (1)

No, not yet. Tomorrow I'm going to write a decent sized response to arghx's last post, he's been really helpful.

Toxindude

My car does the same exact thing yours does in the first vid you posted above . Starts and sounds the same and if you give it gas it falls on its face as well . I am now thinking the FPR is bad its only a little over a year old . What happened in my case was I was going along just fine then got of on an exit ramp and bam car just went to total crap . Does it sound like I am having the same problem here ?

7fanatic

i am having that wxact issue as well and it has caused my car to only fire on one rotor...i think i have the trifecta of fc issues...bad grounding, leaky injectors, and cold starting...

Andrizzanizz

iTrader: (1)

my car is having the same ******* problem too.

Andrizzanizz

iTrader: (1)

any answer for this problem?

Toxindude

Lol I posted to this along time ago anyway my problem turned out to be a blown motor. I lost compression on my rear rotor 2 of the 3 corner seals went bad I bought a atkinsrotory rebuild kit and rebuilt it car has been running strong for 6500 miles now man did I miss driving it.

steve13b

iTrader: (1)

Dont know if this helps but my car was doing the thing my fuel pump had battery voltage on cranking but when it was running for about 2 seconds it lost all power to the fuel pump try a direct 12v to the fuel pump

BAMFRx-7

iTrader: (1)

i had the same problem. after much agravation with diagnosing i finaly pulled the engine and it was cracked apex seal and bad corner seals on rear rotor along with some vacuum leaks.