Those were for testing only right Ken?

 

All wideband controllers have one or two (programmable) analog outputs for the LH and/or a NB gauge.


Serving suggestion. Stock photo. Atypical results. May gain or lose value. YMMV.

 

So (noob questions) would sensor that comes with the wideband kit replace my factory O2 sensor and splice in? Or would I have to weld a bung into my exhaust somewhere.

 

Yes. No.

You can use the connectors from an old stock O2 sensor to both power the wideband controller, and connect one of the analog outputs to the stock O2 connector on the harness. No splicing!

 

You will need to weld a new bung into the pipe and run both NB and WB. The data logger will allow for a NB signal taken off of the WB but I would not trust it.
Do you have a FMU on your kit?

 

Ok thanks I wasn't aware you could use the stock O2 to signal the wideband gauge, good to know! Makes the install a lot easier. Most of the gauges come with a Bosch O2 sensor; could that be used to replace the stock one if it goes bad? I don't think they are heated

OK so the O2 in the kit would give a more accurate signal. Where is a good place to put it on the stock H pipe?

I do have an FMU, currently set up at 8-1 ratio and verified that it is holding boost and increasing the fuel pressure by jumping the fuel pump relay and adding pressure with a bicycle pump. One thing I just found out by doing some digging is I put in the plugs recommended by FAST BPR6EK but they are the same heat range as the stockers and have dual ground electrodes. Would a cooler plug help, maybe a plain jane Bosch WR5DC?

 

You have to fit the wideband sensor (remove the existing NB one). Then power it with the supply box of tricks. You will have two analog outputs, the WB one you can use for tuining (preferably with a SahrkTuner) and a simulated NB signal that you can feed back into your LH ECU via the exisitng connector. Make sure the WB electronics box/sensor is always powered when the igntion is on. Don't power it from the cigarette lighter socket.

 

In some aspects, it will reduce the tendency to detonate, and in some it will increase it. It's all about the temperature in the combustion chamber, and when that temperature occurs. Flame speed is a big part of what the temperature in there is and when. Some things increase flame speed and temperature, other things decrease them. Overall, I'd say that you'd be more likely to experience detonation if you take off the cats and put on an "X" pipe. I sure wouldn't be doing that if it were my car until I had it tuned and set up to make sure that there's as little chance of detonation as possible initially, and then tune further from there.

Keep in mind that just because you can't hear detonation occurring, it very well could be. If you're hearing it, it's occurring earlier and to a greater extent than you think if you're just going by what you can hear. Just because there's no immediately apparent damage, like a blown head gasket, doesn't mean that damage to the engine doesn't occur. A lot of people seem to think that the first thing to go is the head gasket, and that it's kind of like a fuse, in that it will blow before anything else is damaged. That's definitely NOT the case with these engines. There has been more than one of these engines that had damage in cylinders where the head gasket was completely fine. In some of those cases the damage wasn't apparent either until the engine was disassembled and things were discovered then.

Having a good air/fuel ratio is only part of what affects whether detonation occurs. Some people are simply going to tell you that "richer is safer", or that you just need to make sure that you're rich enough and you'll be safe. That's not really true. Once you start getting beyond a certain point, the tendency to detonate will go up with increasingly richer air/fuel ratios. You can't cover up poor tuning or poor system design by just dumping in more fuel. On cars with knock sensors, when the ECU determines that knock is occurring, it responds to try and stop it. It doesn't do that by just dumping in a bunch of fuel. It does it by retarding the ignition timing. The ignition timing is the most important thing when it comes to preventing detonation, unless some other aspect of the system is really bad, to the point that it's going to detonate no matter what you do as far as tuning goes.

All of the Murf kits come with different ignition chips. The stage-3 kits come with both ignition and fuel chips.

Getting a wide band air/fuel meter in the car is definitely a good idea in my opinion. Just remember that all it's really telling you is what the air/fuel ratio is though. It's not fixing anything, and it's not telling you whether everything's safe or not. There's more to it than just what the air/fuel gauge can tell you.

 

Here is a pic of 2 plugs from the driver side bank. they look pretty normal maybe a touch lean. I found out that they are the same heat range as stock, so I am sure that isn't helping me at 8 psi. Of course, these were the ones instructed to put in as per the FAST instructions. I am glad I tossed the instructions halfway through the build!

 

That's not surprising. What is the part number on those plugs?

 

Here is some good information:

http://www.volvoclub.org.uk/air-fuel-ratios.shtml

I also would not consider head gaskets a fuse. Rod bearings or ring lands are just as likely to go. I've actually seen broken pistons the most. I agree mostly with what Z is saying. A/F ratio and spark advance both need to be tuned. You can't just throw more fuel at something and fix timing issues. You need to be pulling ignition timing and have solid A/F ratios. That said, I've never heard that adding fuel past a certain point increases knock. Around 14:1 A/F will give the maximum amount of combustion advance relative to the TDC. Leaner and richer than that A/F effectively retards ignition timing. This has a maximum of about 5 degrees of timing change I believe. New OEM engine controllers include this affect when calculating total timing. Our vintage do not.

 

Ted said. " I put a check valve on the EZF as per my instructions to keep boost out of the vacuum sensor."

Say what?

Vacuum advance units do just that - they advance the ignition timing when they see high vacuum. This normally happens under light-load, partial-throttle conditions, and improves fuel economy.

When you open the throttle, the atmosphere falls in and the intake vacuum goes away, so the ignition advance from the vacuum advance unit also goes away.

If you put a check valve in the vacuum advance line, you will pull max intake vacuum thru the valve into the advance unit the first time that you lift off the throttle and let the engine coast with a closed throttle. That vacuum will be held in the advance unit by the check valve, and you will always have max advance!

Not a good thing...

 

You can tell a lot just from spark plugs, the pic you posted are fuzzy and unfortunately don't show much with the exception of them having the dual ground straps. (edit: to my untrained eye, thanks Z !)

I would recommend /suggest (as others have) you install a wide-band in place of the stock Narrow-Band Ox sensor (the Innovate LC-1 is what I am installing) and start graphing.

Along with the LC-1 I am adding their SSI-4 which will enable you to graph; RPM, AFR, WOT and Fuel Press (need to add a Fuel pressure sender).
This will leave the 4th input open (may be a good place to add a knock sensor input)

http://www.innovatemotorsports.com/x...cat=262&page=1

I would replace plugs with fresh plugs, make a run, and pull them out and take a look, if you use a Macro setting on a digital camera you get some great close up’s.
A non-projected plug, could also help if after pulling timing and keeping your AFR good and your still getting signs of Knock.
The compressed air charge is hot and hot air will increase pre-detonation as you know.

Here is a link for spark Plug reading:

http://www.superstreetonline.com/tec.../photo_03.html

Like others have said; you must know what is going on in there, don’t guess.

Keep us posted, and thanks for sharing.

DaveK9

 

So you're saying it's half FAST? Sorry, couldn't resist.

A lot of the time it can be hard to really tell from pictures, but that plug on the right in particular looks like it indicates that things aren't as they should be.

You're right that going either richer or leaner from the peak air/fuel ratio will have the effect of effectively retarding timing. That's because going either richer or leaner from that point will reduce the flame speed, meaning that it takes longer after ignition occurs for peak cylinder pressure to occur. Fire the spark at the same time relative to TDC, but with a slower flame speed, and peak cylinder pressure occurs later in relation to TDC.

There's some debate as to exactly why adding fuel beyond a certain point can again increase the tendancy for detonation. It will vary from the specifics of one engine to another as far as if it occurs to any significant amount, and how easily, but it does occur. In my opinion, the most likely explanation that I've seen is that it's at least in part due to incomplete combustion that occurs from the excess fuel. Since there's no more oxygen available for it to completely burn, the excess fuel only partially burns. The yellow flame and soot from something like a burning candle or excessively rich welding torch is due to incomplete combustion from there not being enough oxygen for complete combustion. The soot is carbon, and the yellow flame is the hot carbon glowing from the heat, but without oxygen it can't burn, the same as the filament in a light bulb. Some of that hot, unburned carbon from excess richness of the air/fuel mixture remains in the combustion chamber when there's fresh air/fuel mixture coming in for the next cycle, and can then ignite due the sudden presence of oxygen again. It's like when you see the flames at the exhaust pipe on some cars as the hot, incompletely burned fuel in the exhaust suddenly hits the air at the end of the exhaust pipe. Even if it doesn't occur instantly when the fresh air/fuel mixture enters the combustion chamber, things are more likely to ignite as pressure increases during the compression stroke. Technically, ignition before the plug fires is preignition, not detonation, but one can cause the other. With excessive richness slowing the flame speed, the line between them gets even closer.

Again, pictures can be deceiving, but that plug on the right has indications that things are getting pretty hot in there, and the ring on the end of the threaded portion looks like it's got plenty of carbon on it. That carbon is there because the fuel didn't burn completely. There's too much timing indicated. The carbon can be a result of incomplete combustion caused by detonation/preignition from that excessive spark advance, even if the mixture isn't way too rich, or detonation/preignition might be being caused from the carbon if it is too rich. Either way, it looks like too much timing, whether there were carbon there or not.

 

I checked the valve on the ezf and it will let air bleed back through. I took it off and went for another short run to see and it was the same. I get preignition at the last 1/5 of the pedal when it hits the kickdown switch up to there it doesn't do it and pulls like an animal (but boost guage only shows 6 psi). The narrow band gauge shows 2/3 of the way to full rich once the wot switch is activated and in open loop (at about 2/3 throttle). When it cycles it goes from full lean to the rich side of stoich so I am thinking it is working properly. If my AFR was lean enough to have pre ignition when it is 30 deg F outside it should not be showing rich.

I agree with the condition of the plugs carbon on the outside and grayish tan with a white insulator shows ignition issues and unburnt fuel.

I think once the boost is hitting a certain point without retarding the timing it is causing pre ignition. 8 psi no intercooler and no special ignition chips is probably the culprit. Hopefully Tim Murphy has something that can help me out. Another option is getting the boost limiter valve that Carl sells to keep it from going too high. I like that I start getting boost at 2000 rpm especially with the auto but the max boost of 8 psi is freaking me out a bit. Using his valve I could retain my S/C pulley and have the boost come in at the lower RPM and it will just bleed off the excess.

http://www.928m.com/parts/boostlimitervalve.php

It is funny the FAST instructions say that it is only supposed to be 5 - 6 psi and I found an old post on here from Mark R saying he designed it around the PS pulley purposely so the belt would slip and keep boost at a safe level. I can't see that being too good for belt life!

I will keep you up to date with my diagnosis thanks for all the help so far!