Misfiring?

solo_ryder · Post by **solo_ryder** » May 9th, 2006, 11:00 pm

hey, got my ze in with a k8 mani and the k8 ecu and je50 VAF (hope that is the right combo since I havent yet installed the Im from the ZE) and it seems to be misfiring at lower rpms, the timing is dead on and the disty is from my k8 so I know it works. I also changed the spark plug wires and that did not make a difference, the sound seems to go away at higher rpms and it is smooth, could it be a vaccum leek or a TPS issue? May it is the ecu that I am running or the VAF combo... Its just really rough, any ideas guys?

johnnyb · Post by **johnnyb** » May 9th, 2006, 11:21 pm

could be the ECU. IIRC the ecu is set to pump in a smaller amount of fuel into the engine than the KL is supposed to have.

2.5mazda · Post by **2.5mazda** » May 9th, 2006, 11:33 pm

yes, that IS it, wrong computer. I had the K8 computer on my KLDE for awhile, man was it bad. It was dog slow and sounded like it had a cam in it and the car wasnt tuned right!! At high RPM's it ran way to lean and cut out at 5000 RPM's like a turbo car with too much boost. Stick in a probe computer and mass air and you should be good to go.

solo_ryder · Post by **solo_ryder** » May 9th, 2006, 11:39 pm

I have a kl36 ecu, but I thought you were to run the k8 ecu with the k8 mani and the je50...

2.5mazda · Post by **2.5mazda** » May 9th, 2006, 11:43 pm

no way, not good, not enough fuel delivery. Think of it this way, your 2.5 is getting the same amount of fuel as your 1.8 was. It cant work that way, at least not well. Just trust me, you arent getting enough air or fuel. I would say you are probably losing 15-20 or so potential horsepower between all of that that you have going on.

When I got mine running right, it was night and day difference, almost like a small nitrous shot.

solo_ryder · Post by **solo_ryder** » May 10th, 2006, 12:34 am

I dont think that a DE would react the same way as a ze for the ECU?

XxantwawnxX · Post by **XxantwawnxX** » May 10th, 2006, 12:36 am

I had the k8 ecu on the ze for years np at all..cept for being rich.

solo_ryder · Post by **solo_ryder** » May 10th, 2006, 1:19 am

Thats what I thought, the damn this is not ideling worth shat. Gotta figure it out tommorow...

solo_ryder · Post by **solo_ryder** » May 10th, 2006, 2:26 am

Any other ideas?

2.5mazda · Post by **2.5mazda** » May 10th, 2006, 8:23 am

stick that computer in, I am sitting here telling you I had the EXACT same problem. Make sure the mass air matches the computer and you are using the correct injectors.

kanipimp · Post by **kanipimp** » May 10th, 2006, 8:30 am

I'd say it's because you're still running stock injectors. I ran the K8 ecu, Je-50, K8 IM for a year with no problems exept it ran rich. It was slow and torqueless till I swapped out the fuel rail and injectors from the ZE IM. Mind you having the ZE IM and proper ecu will make you think your engine used to be crippled

Your ecu will still think your running the smaller 170cc injectors, so you'll be pumping more fuel. Try swithching the whole rail unit with injectors still in and see if that helps.

RacerX · Post by **RacerX** » May 10th, 2006, 9:48 am

Isn't the ideal ZE set up a ZE block, kl-31 cams, MS8 intake manifold and a kl31 ECU ?

solo_ryder · Post by **solo_ryder** » May 10th, 2006, 1:30 pm

RacerX wrote:Isn't the ideal ZE set up a ZE block, kl-31 cams, MS8 intake manifold and a kl31 ECU ?

Yea, well, I am looking into getting a MS8 IM from another member on this board but they dont pm me back, then I can run my kl36 ecu,

2.5mazda wrote:stick that computer in, I am sitting here telling you I had the EXACT same problem. Make sure the mass air matches the computer and you are using the correct injectors.

Yea well u were running a DE, and I am running the k8ecu/im and je50 vaf so those are all the right combos, it sounds like it is running on 5 cyclinders that is all, will check the plugs today.

Post by **Custommx3** » May 10th, 2006, 3:43 pm

The K8 ECU has a closer fuel map to the KLZE than the KLDE ECU does.

solo_ryder · Post by **solo_ryder** » May 10th, 2006, 4:45 pm

Custommx3 wrote:The K8 ECU has a closer fuel map to the KLZE than the KLDE ECU does.

Yes that is what i had figured, I may have some sort of vacuum leak somewhere, I am going to leave it alone until I get a good IM for the car, but drving in town is fine, anything above 1.5K rpms is good.