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Hey Guys, I need some help troubleshooting my 92 FD RHD. I've spent a lot of time trying to resolve the boost issue with this car and have found nothing but frustration. For some reason, the car won't make more than 5-6 psi in any gear after it's warmed up. I downloaded my tune/datalog and sent it to LMS EFI, which they took the time to verify the map and boost settings, but nothing out of the ordinary was discovered. The car was running spot on 10-8-10 for the last six months. I decided to add a wideband display and launch control on the Haltech; after enabling those features via software, I went for a test drive, and that's when the boost issues began. I then attempted to raise the (boost control duty cycle) through the Haltech, and the car was not responding to any changes.
I attempted to roll back to a base map to see if that was the problem and nothing. Finally, I took everything apart about three times. I verified all the actuators, all the solenoids, vacuum leaks, vacuum chamber, boost leaks, pressure chamber, Viton check valves, turbos, and everything still looks to be okay.
The only thing that seems weird and maybe an issue is the Turbo control actuator (TCA); the TCA rod doesn't move while turning the ignition to Key on / key off. It will have movement if I try to rev the car to 3k and above, which I recorded and confirmed with my phone. But no response to the KOKO troubleshooting step.
Looking at some data log runs, the Haltech has captured the turbos actuating from primary to secondary, which is also confusing. I thought the primary turbo needed at least seven psi to activate the secondary turbo. But based on my datalog, that doesn't seem to be the case.
The car has undergone a complete overhaul with newer 99 turbos, simplified sequential setup, silicone vacuum hoses, new sequential turbo control solenoids (Charge control, Charge relief, and Both turbo control solenoids), Viton check valves, and some basic reliability mods. Nothing's been spared in this build, which makes it even tougher to pinpoint.
Anyways any help would be appreciated.
Thanks,
-Sammy
Last edited by Samito Built; 04-25-20 at 02:20 PM.
With the Haltech you're getting into some grey area, not a lot of people have done sequential control with the Haltech that I know of. I know it can do it but I don't know the ins and outs of how it works.
That said, are you getting a steady 5-6 psi of boost to redline? If it's going to redline the turbo control system is doing something at least. If the turbo control door stays closed the boost will drop to nothing after transition (around 4500 rpm).
Also the KOKO test won't do anything with the Haltech - that's a stock ECU thing. I don't even think the PFC does the KOKO test.
The question comes down to what are you using for boost control? The factory actuators with no control solenoid will do about 7 psi or so. It almost sounds like you just don't have boost control, just running off the spring pressure. If you have new 99 twins the restrictor pills are built into the factory compressor outlet nipples so you don't have to sweat those, but that only works with the factory boost control and I don't know how well the Haltech controls that or if it even does.
[QUOTE=DaleClark;12407612]With the Haltech you're getting into some grey area, not a lot of people have done sequential control with the Haltech that I know of. I know it can do it but I don't know the ins and outs of how it works.
-Interesting didn't give that much thought.
That said, are you getting a steady 5-6 psi of boost to redline? If it's going to redline the turbo control system is doing something at least. If the turbo control door stays closed the boost will drop to nothing after transition (around 4500 rpm).
-Yes, 4-5 psi before the transition, after 4500, the boost stays consistent 5-6 psi until redline. I've captured a datalog with all this information, and when I play it back, it shows all of the sequential turbo control systems functioning. That leads me to believe a boost leak, which has been ruled out early in troubleshooting.
Also the KOKO test won't do anything with the Haltech - that's a stock ECU thing. I don't even think the PFC does the KOKO test.
-Ok, then I can rule that out.
The question comes down to what are you using for boost control? The factory actuators with no control solenoid will do about 7 psi or so. It almost sounds like you just don't have boost control, just running off the spring pressure. If you have new 99 twins the restrictor pills are built into the factory compressor outlet nipples so you don't have to sweat those, but that only works with the factory boost control and I don't know how well the Haltech controls that or if it even does.
-So my Haltech is an Elite 2000 with a factory plug and play harness. It utilizes the factory Mazda loom without any splicing or modification required. Everything works like the stock setup except for the map sensor, which is plugged directly to the internal map sensor inside the ECU.
Now with boost control, My Haltech does use the factory solenoids. Turbo wastegate control and the turbo pre-control solenoid. I can see the signal to those solenoid connectors with a power probe circuit tester and all 4 (Charge control, Charge relief, and Both turbo control solenoids). So continuity is coming from the ECU to the solenoids. I tested those solenoids yesterday, and they seem to hold vacuum, pressure, and pass the resistance test. The only thing I found weird was the pre-control solenoid; when I put 10-12 psi of pressure on port A wit
h a mitty vac, it wouldn't release that pressure through port B when the connector was hot in current. If I grabbed the wastegate solenoid connector and did the same test, then Port B would open as it should. Not sure entirely how those work and activate on the whole sequential process.
I also cant make 7 psi even If I try to disconnect the connector off of "I" which is the Wastegate control solenoid. In the past experiences, I've had overboost issues, and when I disconnect the connector off wastegate solenoid, the car will limit to 7 PSI spring pressure, which doesn't seem to work on my car. If I cant make 7 psi, then something mechanical must be holding the car back. That's just a guess, not sure though.
If you're having low boost issues that are consistently low and the transition is still working fine, I would smoke test and boost leak your system. I had a boost leak on my twins for year and it wouldn't go above 7 psi and I was too lazy to diagnose it even though everything was functioning as it is.
If you're having low boost issues that are consistently low and the transition is still working fine, I would smoke test and boost leak your system. I had a boost leak on my twins for year and it wouldn't go above 7 psi and I was too lazy to diagnose it even though everything was functioning as it is.
I agree that it sounds like a boost leak. IIRC, the rubber connector tube coming off the turbos has a tendency to crack where you can't see it or even feel it very well.
I would do a pressure test. My turbos were were getting about 5psi no matter how much I turned up the boost controller. I decided to do a test and had leaks everywhere. Everything good. Now.
You still have the stock coupler going to the intercooler hot side. Those crack.
Also check the two 1" diameter hoses coming off the y-pipe for charge relief and air bypass.
Do you hear any new noises?
-Thanks, I noticed the 1" hose for BOV turns by hand so I need to buy a new clamp to address the issue. As far as noises are concern I don't hear anything different.
Originally Posted by zweetz32
I would do a pressure test. My turbos were were getting about 5psi no matter how much I turned up the boost controller. I decided to do a test and had leaks everywhere. Everything good. Now.
-Awesome pressure tester kit. I plan to try out the same test kit this weekend and report back with my findings.
The hoses to the BOV and CRV many times are loose because the hose is rock hard and can't seal any more. You can try the clamp but you may need to replace them.
I found silicone replacements that work wonderfully for a great price. My thread on it -
The boost leak tester you can make many times with stuff from the hardware store. You will need an air compressor to pressurize the system, I would crank it down to 15-20 psi or so.
I've replaced both 1" hoses and the 2.75'" coupler that fits between the 99 y pipe/ IC and came back with the same problem. I performed a boost leak test and found a small leak on the o-ring between the TB and Elbow. I also found some bubbling with soap and water at the lower IC pipe.
*The latest update ordered a new elbow o-ring, and a CXRacing Intercooler Piping Kit to replace all the remaining factory couplers.
Day 1
After a few weeks, I was able to buy the TB oring, HKS hard pipes, new silicone couplers, and T-bolt clamps. Took the car for another test drive and boost is still in the 5-6 psi to redline, it just gets there a little faster now. I performed another boost leak test and couldn't find any leaks.
Day 2
Reinstalled the stock map sensor and replaced the Haltech Elite 2000 with a factory ECU. Unforntualy the car only made 3-4 psi to redline with the same problem persisting.
I know something big must be wrong with the sequential system. What could cause me not to make wastegate pressure at 7 psi if there are no leaks in the charge pipe system any ideas?
Last edited by Samito Built; 05-29-20 at 01:47 PM.
Also, I just zoomed in on one of your pictures, I'm not 100% sure those are the '99 280hp twins. They could be the N3C1 twins. Where did they come from?
On the secondary turbo compressor housing is a stamp with the model of the turbo. It's right next to where the secondary turbo aluminum inlet bolts on, you can see/get to it fairly easily from under the car. It will either say N3A1, N3C1, or N3G1.
The car generally starts, runs, and idles well? No high idle or anything funky? Good compression?
The car starts,runs, and idles fine. There's no signs of low or bad compression, but that hasn't been verified since FEB. I'll be checking this next week when my new digital compression tester arrives from the states.
You said you have 99 twins, are they new or used? Did you install them or did they come with the car?
They have 20k miles and were installed during the overhaul I did last year. I did double-check the turbos to see if they had any shaft play or endplay and were still in great shape.
How are you reading the boost for the engine? Is it possible the boost gauge is lying to you?
I have two ways to read boost, through my Haltech and AEM X series boost gauge. They are both reading the same and are connected to two different vacuums ports on the uim.
Current mods:
13B-REW with street port Rebuild was done by HME Rotary in 2016 Good compression near 100 psi on all faces.
Simplified Sequential Setup Engine harness rewrapped
Vibrant silicone hose kit
99 Spec twin turbos – low mileage
99 Spec steel motor mounts
99 Spec aluminum Y pipe
Ported wastegate
Banzai oil pan brace
Banzai block off kit
New oil pan
New battery cover
New oil pressure sending unit
New gaskets and seals
20-50w VR1 mineral oil
OEM oil filter
ACT clutch
ACT pressure plate
New remanufactured starter
New throwout bearing
Royal purple fluid
Suspension: Öhlins DFV coilovers Brakes: Stoptech slotted brake rotors (F+R) Hawk HPS pads Russell braided lines Motul dot 4 brake fluid
Haltech Elite 2000 with Series 6 PNP harness
AEM X Series analog wideband gauge
AEM X Series analog fuel pressure gauge
AEM X Series analog boost gauge
Fast Air Reacting temp sensor
New turbo selenoids replaced - All four that control sequential boosting Fuel Aeromotive FPR Walbro 485 in tank fuel pump Painless fuel pump rewire kit ATL Electrical bulkhead
HKS fuel rail adaptor
New fuel filter
Induction Blitz induction system
NGR 38mm Type S blow off valve
Cooling Banzai Racing AST billet filler neck
Fenix Aluminum 3 row radiator Prestone coolant 50/50 Silicone hoses HKS rad cap
Intercooler ARC SMIC
Exhaust HKS downpipe heat wrapped
BONEZ Racing hi-flow cat
Custom SS 76mm exhaust dual tip
Also, I just zoomed in on one of your pictures, I'm not 100% sure those are the '99 280hp twins. They could be the N3C1 twins. Where did they come from?
On the secondary turbo compressor housing is a stamp with the model of the turbo. It's right next to where the secondary turbo aluminum inlet bolts on, you can see/get to it fairly easily from under the car. It will either say N3A1, N3C1, or N3G1.
Dale
They did come off a 99 spec car but they are the N3C1 version.
You bench test the BOV and CRV yet? Pull off the cat to see if it's broken up or clogged?
Yes, they both have been tested on and off the car and are working fine. I haven't pulled my Bonez Hi-Flow Cat off yet. Been thinking about removing that tomorrow to check it off the bucket list.
Last edited by Samito Built; 05-29-20 at 04:38 PM.
the 99+ cars had two options, 265ps or 280ps, the 280ps has the special turbo, the 265ps has the N3C1 turbo the same as the US cars
needless to say either turbo should still boost more than 7psi....
dumb question, but how are we reading boost?
I have two ways to read boost, through my Haltech and AEM X series boost gauge. They are both reading the same and are connected to two different vacuums ports on the uim.
Can the car even make over 7 psi of boost without the actuators hooked up to anything? I.E. plug the boost sources on the primary compressor housing and have no boost going tot he actuator nipples.This obviously takes all boost control out of the equation so be careful, but it will tell you if there's an issue with the major components.
After two long months of troubleshooting, the low boost issue Is finally resolved. I removed the BONEZ Hi-Flow Cat and found broken elements inside, which probably came apart from enabling the launch control. Without a doubt, my fault and should have known better. I stripped the cat, reinstalled the mid-pipe, and verified the target boost. Thanks again for all the help, guys!
Yeah cats can't handle 2-step and crazy stuff like that, now you know .
Good thing is you have the system nice and tight now, you know you'll be good for a long time to come.
BTW, the N3C1 turbos are just the slightly updated version of the original turbos. They are much less prone to cracking but performance-wise are identical. They actually started appearing around '95. If you say "99 spec turbos" most people will think of the 280hp turbos with the different wheels and abradable seal on the compressor wheel.
04-25-20, 02:16 PM
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