Hello to all of the kind and knowledgeable folks on the forum (and smart a**es too!).. I've been enjoying the great threads and comments here for years... I haven't posted much recently but I thought I'd share with you my new post-divorce economy car that I picked up that needs some fixing up....they said it needed a head gasket... but it ran good enough...so I gave them a grand and babied it home...I used to have a new ML500 and a 540i in the garage...but now I drive cheap 25 year old civics and park on the street....I need to live within my means!

I've owned 3 stock VX hatchbacks and a stock high mileage EX coupe over the last few years. But this most recent one is my favorite.... it also needs the most work! Its a 95 EX that has been heavily customized. I'll need to replace the head gasket and get it running smoothly soon...I want it to be reliable and affordable...this is my daily driver. I would like to see if I can get this factory D16Z6 up near 180whp with the stock internals... something a little more peppy!

The car has 120,000 miles on it with an old skool Greddy turbo kit with a front mount intercooler. The entire exhaust looks modified too. It currently smokes under boost and only pushes about 4-5psi with no overheating issues. Sounds like it has an aftermarket fuel pump when I turn the key on and possibly bigger injectors but I can't tell for sure.. The automatic transmission seems to hesitate when upshifting too...probably on it's last legs...Would appreciate your suggestions and tips to see if I can get it nursed back to good health...maybe even better than it was before!

 

You won't have much tunability unless you upgrade to a chipped ECU or some kind of RTP like Hondata, Neptune, etc. Your car is currently using an FMU, which is ancient technology in today's world of tunable ECUs. I would recommend upgrading to a real tunable ECU and getting it dyno tuned. Honestly, if it's your daily I would recommend pulling the turbo kit off.

Can you tell what is burning to create the smoke under boost? It could be over-fueling, or the turbo seals could be bad, or it could be head gasket related.

 

Thanks how would I know if the ECM has been chipped or modded? I pulled took off the kick panel to inspect and it looks stock with no extra ports or pins or anything...is it possible it could have been modded for a richer mix under boost without being chipped for tuneability?

I can see it when I put my foot into it, under 3-4 psi boost the smoke comes out pretty bad out the exhaust... previous owner said they took it to a shop and it was determined the head gasket was bad....I will get a compression test done this weekend and see how it looks..

The previous owner was said it was originally set up with a California legal CARB Greddy civic boost kit, but someone has since removed the original BOV and replaced it with a non-compliant SARD external BOV...there's probably no way to find the original one at this point...further mods to the ECM may make it more difficult to get it to pass legally...but I don't plan to stay in CA forever!

 

Pull off the cover of the ECU and post a picture of what the board looks like. I'm pretty sure these older Greddy kits just used the FMU (large black aluminum disc-like thing on the firewall) to increase fuel pressure (12:1 ratio I think?) during boost to control the fuel. I'm not familiar with CARB compliance, but I don't think any tunable ECU will get past a ref.

Get the compression test done, and a leak-down test if you can. Try to determine if the smoke is oil, fuel, or coolant.

 

That aluminum thing on the firewall, do you mean this??

 

This thing on the firewall

 

Took out the ECM carefully...it's a P28-A52...

 

Yes. It's an FMU or rising rate fuel pressure regulator. OEM regulators are 1:1 for each lb of boost. The FMU raises fuel pressure at a rate greater than 1:1...I think the typical ones are 12:1, so a 12 psi increase in fuel pressure for each 1 psi of boost. So your injectors don't run more duty cycle in boost with these things...they just see more rail pressure.

 

ECU is not chipped - nothing in the 28-pin slot in the upper left corner of the picture.

 

Ok so an increase in fuel pressure but no increased duty cycle for the injectors is not the ideal way to go...so I've read enough other threads about the Walbro 255 is an upgrade over the stock fuel pump...but would that necessary for only 180whp?

What if this car already has larger injectors, would the FMU then be sufficient for 180+ whp? Or should I scrap it and upgrade to a Walbro fuel pump and some 340-450cc injectors...

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unless you go to an upgraded ecu, you won't be able to run larger injectors without over fueling out of boost. You also wont be able to go over about 11 psi (stock MAP sensor) but thar should be ok for your goals. I would do a 255 lph pump just for safety. I'm not sure what power levels the FMU good for. It works, but there are probably spots on your map which are not at the ideal AFR, and you can't do any adjustment to your timing maps.

 

this is a stock ECU. Not chipped or anything. Probably why you're having difficulty with the turbo system now; in need of a REAL tune.

 

You'll want to remove that FMU out of the system completely. It is more than likely paired to a set of stock injectors. I'd also suggest pulling and inspecting the pump (just pope out the lower back seat cushion and the sending unit is right there)/replace the sock. I would also suggest pulling that hose that is connected to the VC vent and make sure the opposite end isn't capped off (that hose would have originally been routed back to the turbo compressor inlet pipe)

I would lean more towards it being fuel smoke and not a hurt head gasket.

Upgrade to a tunable ECU, set of injectors if you intend on keeping it turboed.

Making 180whp out of the 15G on a D series with a stock auto trans is going to be quite a stretch due to the load, shift point, and turbo size. Gate pressure is only 5-7 psi out the box, so if its making 3-5 before shifting then it's where it should be.

Best of luck on the build, I've owned 3 of those 15G kits (looong time ago); the first of which was on an auto trans D16 as well. ('ve also got that same ol' Momo steering wheel in my "I'll use it again one day" pile here )

 

My EX-gf had the same setup in her Civic coupe. For those Greddy kits, the ECU was left untouched.

OP, if you want to keep that turbo kit, I would upgrade the fuel system, check to see if the turbo seals are messed up, perhaps rebuild the internals and...LOSE that body kit. That look screams 1999 !!! lol

 

1) Thanks for the tips! So these were probably a common turbo kit back in the day...glad to find someone who is familiar with them! So I'm leaning towards the injectors being stock size like you said. Not sure how to confirm this, but they don't look like he other stock injectors on my last EX coupe that was bone stock... however based on your description of the kit I'd assume they are a stock size..

2) I'm definitely going to put the fuel pump inspection and sock change on my list of 'things to do'! This is a good tip thanks.

3) What does VC stand for? Vapor Canister? So it has a vent hose that was originally intended to vent somewhere other than the atmosphere correct? Should it have vacuum? Probably not?

4) Head gasket issue was confirmed by the previous owner's mechanic. That's why they sold it so cheap. I'll be pulling the head soon after compression testing...just for curiosity's sake.

5) I'm definitely going to put the chipped/tuneable ECM on my 'to buy' list, along with larger injectors...so I can control the boost more accurately... this list 'to buy/upgrade' is becoming large already! The greedy, insatiable boost monster has been haunting and tempting me...been staying awake too late at night!...so I'm aiming to keep it modest and affordable, and reliable too. Will consider room to grow with any new parts that are purchased! Probably have to address the auto tranny eventually too....but for now, just a little extra for getting up to freeway speeds. I can't even keep up with a new stock Hyundai or most any other new economy car these days under heavy acceleration! That is just not acceptable Lol

 

1. Extremely popular (over priced and under performed, but carb legal and one of the very few out the box bolt in options at the time. They were fun. Mine actually came with the blue box piggy back, not the Vortech FMU. I still have the blue box wiring diagram saved somewhere)
2.
3.Valve cover
4. Does it over heat? White smoke? Coolant/oil mixed? Temps go up when boost is reached and don't come back down?... or does it just smoke some when in boost? It could have a HG issue...but it could very well not. It definitely wouldn't hurt to put a gasket and stud set in; but I'd test first and move that down to "after fuel/tuning pieces" on the priority list.

 

Ahhh yes! That breather hose is just hanging down to the back uncapped.

 

I'm probably in the position where I'll repair the head gasket if needed, then upgrade the ECU and fuel system, then drive that way, until either the engine or the automatic transmission gives out...then possibly do a manual conversion since I already have a EX 5 speed and some other necessary parts in my storage unit. Any parts purchased will have room for future HP increases....I should get some miles out of it first tho!

Seems like you have lots of old school parts around! My Momo wheel is coming apart at the seams...but it's not on top of the list...I'll need to check around for some better injectors and a tuneable ECU. I'll also have to educate myself about the differences between Hondata, Crome, eCtune, Neptune, etc...and figure out where to find a good local tuner near Torrance/Lawndale in L.A.

 

Any idea what turbo is in this kit? Was it a Greddy T2 or??? Would like to know more about it, to see if it's capable of getting to the hp goals of 180+... Seems to spool up really quickly whatever it is...

And yeah...that BODY KIT lol...it even has Lexus GS taillights converted to LED red brake lights too...somebody put a lot of Bondo on that trunk 😁

 

Was an MHI TD04H if I remember right.

 

No it doesn't overheat, even under boost. It doesn't have the typical head gasket fail indicators... No milk chocolate colored motor oil on the dipstick,no oil in the coolant, no white steam train exhaust, etc. It smokes a lot under boost. And the mechanic said it was bad. The coolant does have a faint smell of exhaust however. I don't have a block tester so I'm going to borrow one from Autozone and get some test fluid.

But I'm getting really uneven compression readings on cylinders 2&3. They are about 20 psi less than cylinders 1&4.

 

Compression readings were not good for cylinders 2&3 and the block test kit indicated exhaust gases in the coolant so I pulled the cylinder head and sure enough it was leaking. Probably from the FMU and lean air fuel ratios under boost conditions. Time to order some new parts!!!

 

Making progress...new ARP head studs and a Comatec head gasket...

 

And a fresh rebuilt stock cylinder head just so I could use the old one as a spare...

 

Also a new water pump, crank seal, cam seal, and


timing belt!