Help me tune my ZE.

[greenstorm]

My ZE feels slow and gets bad gas mileage.

I have a 92 GS with a KLZE in it. Included in this mess is......

K8 Intake Manifold on it. I'm sure this doesn't help. How bad is this for my engine?

K8 ECU +JE50. I'm looking at picking up a kl36. If any of you have a good ECU, I would like to purchase it.

Headers, 2.25" custom exhaust, cold air intake.


Also, my knock sensor is throwing codes. Does the ECU dummy down the engine when this happens? Any way to work around it?



What should I do first to help my engine run better? Any suggestions welcome.

[PATDIESEL]

Sounds like you need to run through a few things.
1. yes the knock sensor mode will make hte car run in limp mode = bad gas mileage and slow so fix this first.
2. get a DE or curved neck ZE manifold. What injectors are you running? If they are from the K8 mani then you need to at least get some ZE injectors.
3. When was the last time you put in new O2s, or did a good tune-up? Who set your timing last and hopw long has it been since you did a timing belt and tensioner?

[greenstorm]

I got fresh o2's with the swap. I set my timing when I did the swap and also installed a timing belt. This was 5 years ago and it's just been sitting, I don't even know if I remember how to do it anymore, lol. I have some homework to do.

I'm pretty sure I swapped the injectors from the ZE manifold, so i'm using the ZE injectors.

knock sensor makes me pretty much take the whole car apart, then I won't know if it works until I put it all back together... ugh... is there any way to trick the ECU to think that it's working?

I also am throwing EGR codes because I removed them. Will that make the engine go into dummy mode too?

Thanks for helpin me out

[wytbishop]

EGR codes won't affect the tune of the engine.

Replacing the knock sensor is not all that bad. Well actually it sucks but can be done. And you should be removing the intake manifold anyway to get the proper one on there. With the IM off it's just a matter of removing the coolant pipes in the valley and then pulling the sensor.

http://www.mx-3.com/manuals/showimg.php ... F2-156.gif

[greenstorm]

Yeah, It looks really bad. Have to drain coolant, take off fuel lines, get a new IM gasket... ugh. Puke.

How bad is the k8 manifold? is it a really big bottleneck? How much is a ZE mani? I feel like this is expensive.

I have a knock sensor off my old k8. What would happen if I just plugged that in and let it sit there on the side? lol

[Nd4SpdSe]

knock sensor makes me pretty much take the whole car apart, then I won't know if it works until I put it all back together... ugh... is there any way to trick the ECU to think that it's working?

A resistor of it's ideal value would do that. I did it on my truck, but that's because even with the new KS it was throwing false knocks and I got pissed off with the poor milleage and it retarding my timing and limiting my boost.

K8 Intake Manifold on it. I'm sure this doesn't help. How bad is this for my engine?

It's not bad for the motor, people uesd to do it all the time, but it restricts airflow and in that sence limits power. It won't affect milleage since your not limiting enough air with that IM in regular driving, only when pushing it hard

K8 ECU +JE50. I'm looking at picking up a kl36. If any of you have a good ECU, I would like to purchase it.

Next to the bad knock sensor, this is going to affect your milleage in a big way. You have nothing that controls the motor for a 2.5L V6. With the K8 ECU and the "dumb" OBDI system, it just thinks it had a K8 in there, with 180cc injectors, but while you have a KLZE in there with 220cc injectors, so all it's math, programed maps and the like will be thrown off. If it's trying to dump in X amount of fuel, but it doesn't know you're injectors are now 22% bigger, so you'll roughly be dumping in 22% more fuel than needed.

Fix your knock sensor and get a proper ECU/VAF combo, those are your 2 major obstacles.

[Daninski]

I got fresh o2's with the swap.

The new O2 sensors will help but really, without the proper intake and ECU your not taking advantage of the full potential of the ZE.

Get a curved neck or mod for a straight neck, chip or KL31-36 ECU and enjoy your ride.

[greenstorm]

Thanks for all the help everyone. I looked at the old K8 knock sensor, and I have no idea how to get it out. I was going to try and just plug that into the ecu somewhere and not in the engine if it still works to trick it (probably won't work but worth a try)

Does anyone know the correct resistance of the knock sensor? I'm looking in the manual but i have no clue where to find what I need to know. I'd rather trick it then try and fix that (insert expletive here for knock sensor). Soooo much work

my number 1 priority right now is that sensor, so any tips would be great.

[greenstorm]

if it just needs continuity could I just put a wire between the terminals in the plug? I don't know if this is what it needs, more research incoming!

[greenstorm]

found it. F2 - 148 in the '92 online manual.

0V @ ignition switch "on"
0.7V @ idle

Incorrect voltage = Always 0V or VB (does that mean battery voltage?)

I wonder if I had 0.7V, it would throw a code before ignition..... IDK. This suuuuuucks.

The correct thing to do would be to replace it. I don't know where to get that socket and I really don't feel like tearing down my engine that far. So mad, bro's.

How hard is a megasquirt?

[Ryan]

Just something to think about:

People who build higher power KL's (300+ hp) find that the intake manifold is THE weak link. The K8 is ridiculously smaller. I'd say swapping the correct manifold would free up a good 10% of the power from where you are now.

do you own an angle grinder? just MAKE the socket for the knock sensor, took me 5 mins, the hardest part was trying to clamp it down properly while I went at it.

MS is very hard, or very expensive, those are the options. From build your own (literally solder all the stuff onto the PCB) or buy a P&P unit for $500-$1000. Either way, MS is way harder than changing the knock sensor. You probably need new coolant anyway.

[Nd4SpdSe]

I'm surprised it doesn't say, but I know in my Xterra factory manual, it lists the testing range values of a good knock sensor in resistance. I split the difference and put in a resistor in there. Not idea and I wouldn't recommend it. Mine went and i put in a new one in a relocated spot because it's even more of a pain on the Xterra on how deep it's burried, especially if you have the S/C.

The connector is easy to get to on the Mx-3, could get someone to measure the resistance of their working one.

[greenstorm]

looks like it takes an 02 socket.

where would you relocate it to?

[davmac]

The knock sensor is like a microphone tuned to a set of frequencies associated with engine knock. I suspect you could connect a good knock sensor to the connector and locate it anywhere near the engine. In other cars it is mounted to the block near the freeze plugs (also a PITA to get to), on the head or even between engine and transmission housing. I believe it is threaded so you could get creative with a homemade bracket attached elsewhere to the engine. You could even tie it off somewhere in the engine bay - as long as you don't mind that it will probalby never see engine knock and not do its job of protecting the engine.

If you do replace your IM it is a perfect excuse to put it in its place. Note: IM gaskets are steel and can be reused many times.

[Ryan]

Just so you know, the knock sensor is screwed into a heavy piece of steel, and I betcha that works as a microphone for it. I would not suggest relocating it, as its in a prime position to hear every cylinder equally well.