georgefury1

I have installed my Greddy kit, 12/1 fmu, MSD Sebring but I seem to be detonating at tip in and the lower psi. My A/F gauge is reading a little rich from 1-6PSI so I don't think it's a fueling problem. At full boost everything is fine and the car pulls great. Sometimes it sounds like there is a little detonating before boost too. I have tried pulling more timing out but it does not seem to be helping. The plugs look fine but I'm scared I'm going to hurt my engine if this keeps up. I know this is very vague post but any help brainstorming would be helpful.

DammitBeavis

How are you controlling your timing, with the MSD box? If you're running good and rich it would be quite difficult to be getting knock at 6psi unless you were running way too much ignition advance.

Fireindc

iTrader: (13)

My vote is dying fuel pump, or incorrectly hooked up FMU.

turbobluemiata

iTrader: (8)

do you have a real air/fuel gauge (wideband)?whats the name of the cartoon for your avatar I loved that show but forgot the name

georgefury1

I am controlling my timing with the MSD and 2 degrees pulled from stock. The fuel pump is new so Im pretty sure its AOK. Do you guys think it could be spark knock?? Its not very loud and with it happening before boost it really has me confused.

georgefury1

Its a Autometer gauge, non wideband. The avatar is from the TV funhouse. Its the car from the Ambiguously Gay Duo.

turbobluemiata

iTrader: (8)

get a wideband

Savington

iTrader: (31)

Hook your AFR gauge up to your alternator and read the output. At least it's reading something accurately, then.

Get a wideband.

Toddcod

iTrader: (8)

First check and make sure you didn't get the fuel lines backwards.

Second you are pulling WAY TO MUCH TIMING! You don't even need the msd if you are running 8 degrees of timming at 6psi.

So after checking fuel lines. Turn you base timing to 13 or 14 degrees.

(When you set you timing to 8 degrees and then the msd pull 6 degrees, your car is trying to run on 2 degrees. That won't work)

{Don't try this at home, But my brother has his SC m45, 5psi miata set at 16 degrees, for the msd to pull the timing back to base 10 degrees on 5psi...... But we are adding a pulley tommorow and setting it back to 13degrees for 7 psi.}

Good luck.

georgefury1

Dont be a dick. I know Im new at this but its a lagit question.

I will take pic of how I have my fuel lines hooked up tommorow but I think they are correct. I will put the timing back at stock and see what happends.

Toddcod

iTrader: (8)

If you are only running 6psi, atleast set the timming at 13.
You will lose so much power if you don't. Timing in everything on power.

I'm not being arrogant, I bet your car is slower than it was before boost.
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Believe it or not, I just ran into lean tip in problems on my brothers S/C yesterday. And that is what I did.

It sounds like you may need a O2 clamp. Heres what I would do.....( you should do)

Make sure you have PREMIUM GAS ALWAYS!

Find the line commig from the factory fuel pressure riser, trace that to the fmu. Call and make sure that is on the correct spot.

Then make sure the vacuum hose is conected to the intake port. And no vacuume leaks.

Then change base timming to a minimal 13 degrees. ( I don't know your knowlege level, so I'm writing simple for everyone reading in future) Make sure you jump the ground and ten pins, That way there is no timming advance while you are setting it.

Then drive it. If it happens again.

Start driving slow and easy out of boost, get into second gear, creep up to 4000 or 4500rpms and floor it.

If it works great, THEN YOU NEED A O2 CLAMP too.

Running the rpms up to 4250+ rpms before boost, allows you to get past the tip in point. So the ecu isn't trying to pull fuel back at this point. And if it works great, Buy a O2 clamp.

If it still does it. Post it up. There is another route to look at too.



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If you wanna be conservative run the stock timing at 13.

If you are nervous about setting timing to 14 degrees. Set the timming at 12, Make a run, and turn it to 13. Then 14. If any knock occured, turn it back a degree.

But at a small 6psi, you should have no problems at 14 degrees.

(10 degrees is really too conservative on a stock miata. 14 degrees out of boost will never hurt the stock motor.
At 6psi you want your timming to be 7 or 8 in boost.
So you have to set your base higher, and let the msd pull the timing back. Basically 13*-6*pull = 7* timming in boost.

And the base timing higher out of boost gives you more pep than stock anyway!)

avante43

I think what he means is that you shouldnt do ANYTHING until you actually get a wideband. The autometer gauge can only tell you if you are leaner than stoic or richer than stoic. So if the gauge is telling you that you are a tad bit rich, that means that your AFR is probably richer than 14.7. That's not very helpful since your AFR could still be anything from 14.6 to 10.0

Savington

iTrader: (31)

And my reply was a legit reply. Your current A/F gauge is doing NOTHING. It is just a blinking light show reading out totally arbitrary values from an O2 sensor designed to maintain an AFR value you don't want to run. You would be better off guessing your AFRs. Before you do *anything*, get a wideband so you know your air/fuel ratios. The *first* thing real tuners on dynos do is hook their wideband up, because without it you are flying 100% blind.

barryb

Bullshit. Your reply was a punk-*** adolescent response and georgefury1 was correct to call you on it. You're gonna fail big-time in business if you use that condescending attitude with your customers (or boss or coworkers). Budget authority and/or supervisory rating authority will crush smart-*** snark and wit every time.

Bullshit again. "Arbitrary"? How about you pull the data for narrow band O2 sensor voltage vs air/fuel ratio? You're way too loose with your words. A narrow-band O2 sensor, in conjunction with pulling spark plugs and reading them to determine mixture, provides the evaluator enough information to determine quite accurate readings. If you wish to say, "A wide-band sensor gives a greater granularity of voltages vs air/fuel mixture than a narrow-band sensor and thus makes it easier to determine the actual mixture at various manifold pressures and rpms without the interpolation of the observer's judgement", say so. Don't make sweeping unsupported statements. You just confuse the newbs.

"Guessing?" Bullshit again. Reading plugs; works great but is a pain in the ***. Narrow-band sensors; limited utility but easier to provide gross feedback that, when used with reading plugs and using the oil pressure gauge in the 1.6 liter NAs, provides amazingly accurate results. Wide-band; more costly for initial investment but makes up for it in saved labor and more accurate/comprehensive data-logging if your aftermarket ECU supports the wideband datalogging.

"Real tuners"? "100% blind"? Save me from those who think they know everything...sometimes a little humility goes a long ways. Shops use a wideband because it reduces labor costs and reduces risk due to dyno operator inexperience. Hell, Shiv Pathak never used a wideband nor a knock sensor on "Frankenstein" (may it rest in peace) and still pulled 297 rwhp on a *stock* 1994 1.8 liter engine with only a Warner-Ishi RH5B with the T-bird compressor mod! When you match Shiv Pathak's numbers with the same constraints, I'll grant you the mantle of "Real Tuner". Until then, you get the title of "poseur" ( [poh-zur; Fr. paw-zœr] noun. a person who habitually pretends to be something he is not.)

Georgefury1,

Up front, I would never have purchased a Greddy. I won't bullshit you on this. I can understand why but, having attempted to save money by buying cheap in the past (only to have it cost me more in the long run), I can understand where you're coming from. Now, we need to do what we can do to make your system work in a satisfactory manner for you. My first advice, FWIW, is to sell the Greddy and use the money as a down payment on the BEGI-S. Seriously.

Okay, if you don't want to go this route, here's my recommendation...

If you can afford it, get a standalone ECU. Up front, it's expensive, but it's the way to go to make it easier in the long run. Save $20 to $30 a week until you can afford an aftermarket computer with data-logging capabilities and ignition retard vs detonation capabilities. Second, purchase a wide-band sensor. NOTE: A wide-band helps but is not a necessity! Have a muffler shop install a second O2 bung on your downpipe and plug it until you can install the wide-band. If nothing else, everytime you look at the second bung you'll be reminded of that for which you're saving money (and you can install your new toy as soon as UPS delivers it!). If you decide the sell the car, pull the ECU and Greddy off the car and sell them separately. Obviously, you should store the stock ECU and exhaust in the attic or under your bed just in case.

Use your oil pressure gauge as a detonation sensor. The 1.6 liter engines use a carbon granule sensor that is sensitive to the shock waves from detonation. When in doubt, watch your oil pressure gauge; if the needle is wiggling (or slamming!) to the left, you have detonation! Back off the throttle! This doesn't work on the 1.8 models that use the 5 psi on/off pressure switch, only on the 1.6 liter and the 1994 1.8 liter engines.

Also, if you are running the stock exhaust, the backpressure will increase the risk of detonation. If nothing else, change the muffler until you can afford an entire exhaust system. A $40 muffler swap is not as sexy as a $900 titanium exhaust but it works and that is the bottom line. If someone attempts to crawl under your car to see if you have one of those pretty FM or Goodwin Racing chrome exhausts, kick that person in the nuts and tell them mind their own business.

Toddcods' advice was pretty damn good. Listen to him. Be advised I non-concur with him in one area and that is base timing. He recommends a minimum 13 BTDC at idle, I recommend 10 BTDC. I went through the advanced timing technique with both the MSD and the J&S way back in the dark ages and, based upon my experiences (yours and Toddcods' may vary) 10 degrees BTDC reduced the risk of detonation ('course it hits triple digit air temps in Texas). I also have a slight disagreement with how he phrased his explanation of the MSD pulling timing but only because it can confuse a newb (and newb is not meant in a derogatory way). The MSD only pulls under boost so even if it pulls 6 degrees, this is at an RPM/MAP point where the timing is already at somewhere in the area of 30 degrees BTDC. 24 degrees BTDC at several pounds of boost and 5500 rpm can be fine. You'll never see boost at idle with the turbo (generalization here) so you will never have 2 degrees of timing because of the MSD.

For whatever the **** it's worth since I have virtually zero posts on this site...I've had a Miata since 1991 when I returned from the Saudi Arabian/Iraqi desert with a pocket full of combat pay. I've had forced induction since May of 1995 with one supercharger (Camden. Aarrgghh!) and four BEGI units (Warner-Ishi RH5B System 3 and System 3+ , T28 based FM2 equivalent, and the current custom T3/T04E system). I've used rising-rate fuel pressure regulators with MSD and J&S Safeguard (I dyno'd 189 rwhp on that one), standalone computers on the 1.6 liter with the T28 (219 rwhp dyno'd), and the current system (which I've never dyno'd 'cause I just don't feel like it; I've got more important things to do in my free time). Let's see...13 1/2 years of boost on both 1.6 and 1.8 liter engines, stock ECU and aftermarket ECU, approximately 260,000 miles of boost with ZERO engine failures! That's over 4300 HOURS(!) of run time from sea level to 14,000 feet. I repeat, ZERO engine failures and I've never owned a wide-band (I keep saying I'm gonna buy one). I'm not a newb; I'm just tired of posting and reposting the same info over and over. Search is your friend.

And the only reason this post is so long is this is the most free time I've had off since July of 2007. Hustler understands and knows the score since he gets hammered with equivalent (and sometimes worse!) responsibilities.

I'm gonna go fix a drink.

Peace.

georgefury1

So my interwebz has been down for a week so Here is an update. I installed my FMIC and the problem is still happening. I will try what todd says and get back. Does Olderguy still sell 02 clamps?

patsmx5

iTrader: (16)

A narrow band will tell you if you are rich or lean of stoichiometric. That's it. It's worthless for tuning a boosted engine. Relying on a narrowband to dial in a boosted engine is a dumbass idea. If you think you're gonna tell anyone else on this forum otherwise, you're wrong.

Anyways, you seam knowledgeable, but drop the O2 ****. Several people had chimed in and informed the newb he needed one already. This site has a few ******** that jump on newbs. It's not let-me-hold-your-hand-miataturbo.net. Had the OP searched for narrow band O2 sensor and read a while he would have figured out his narrowband was useless for tunning a boosted motor.

albumleaf

iTrader: (7)

Your definition of accurate is what a spark plug looks like? Really? Thanks for your worthless anecdotes but you're still wrong.

Braineack

iTrader: (62)

Hey can you post the spark plug color chart? I can't determine if I'm 13:1 or 14:1...I'm just GUESSING over here.

240_to_miata

iTrader: (2)

i dont have a boost gauge. i just run a vaccuum line into the car and let it blow on me... i can tell what the reading is just from that.

Oh, and who needs a BOV. i have a lever to pull when i let off the gas to release pressure. who needs to spend the money on a blow off valve?

[/ stupidity]

patsmx5

iTrader: (16)

Me too, but I put a piece of tape for the hose to blow on so I can judge boost by the angle of the tape how many boost I'm running.