Error 21 Ignition Signal Problem

[GiJOr33]

The diagnostic computer is giving the above error on my R33 GTSt. Anyone have any idea what i should check to see if it's the problem?

Basically the symptoms are very rich, very rough running. It missfires heaps and struggles to idle. The plugs foul to the point where they are black and wet.

It happened after i took it in for a check up on the dyno so i'm not sure if it's something that just happened to fail or if it's something they have done. I took it back to them and they changed back what they did to the way it was (not much changed).

My car has a HKS FCON V, HKS VPC, and a HKS PFC-FCON.

It's got me buggered. I've tried another Crank Angle Sensor, i've put new spark plugs in. Could it be coil packs, or possible the PTU (the little thing that sits up the back of the engine that plugs into the coil pack loom).

Any tips would be good.

[browny]

AFAIK the computer diagnostics only pick up short/open circuits or out of range signals. When the ECU detects an error in any of the systems it checks it enters a "safe" mode where the engine is only allowed to run with very conservative settings (ie rich, retarded timing, rev limited). The actual settings vary depending on the failure detected.

So the most obvious thing to look for is something that has been accidentaly left unplugged, which you have probably already done.

Next you need to start investigating individual components and their wiring. It could be something as simple as an earth that has been left off or a wire in the loom that has been broken somehow. It also could be something that has failed. Try playing swapsies with known good parts.

A multimeter and an engine manual are your friend.

[GiJOr33]

yeah... i don't have an engine manual or a manual for the HKS computers. Oh well... i'm tipping that something has come loose under the foot well where the FCON V is sitting. The car ran perfectly fine before i dropped it off for a tune up. I've looked at all the things in the engine bay to make sure they are all plugged in correctly, such as the igniter, the coils, the CAS. We changed over the CAS to see if that was the problem, it wasn't. I've got a spare set of coil packs and an igniter here that i can check. All the injector plugs are on etc so the only logical thing to check is the dogs breakfast of wiring looms under the passenger dash/footwell

[AutoTrust]

Have you tried resetting the ECU? If it is running in safe mode due to an intermittent problem this may clear it up...... Worth a try

[GiJOr33]

yeah i've pulled the battery out (flat from trying to start it on fouled plugs), so it will have the night to reset, tomorrow i'll try and start it again with clean plugs and a different Ignition Amplifier as well. Hopefully all will be ok.

[rb25]

Take it to somebody that has a nissan consult and card for your car. Makes life very easy.

-rb25

[GiJOr33]

well i started it an still no good. The guy who buggered it up had a Snap-On box that plugged into the port under the steering wheel. That's where i got the Error 21 from. I have a funny feeling that he's wiped the HKS computer of the tune that was in it so it's back to factory defaults.

[GiJOr33]

Well i have changed everything except for the HKS computer. I've changed crank angle sensor, coil pack igniter module, i've tested all the coil packs (all 0.8 ohms), i've swapped over the factory computer with another one. So all that is left in the ignition circuit is the HKS FCON V, HKS VPC, and PFC-FCON and also the wiring loom. So either the HKS computer has crapped itself (or he fried it), or the wiring loom is damaged.

Starting to piss me off. I wish i knew what this other tuning place had done to it...

Andrew

[blind_elk]

Have you checked the power supply to the ignitor / coils? Or the relay for the coils?

Error 21 is raised when the ignition signal isn't generated. If it was a problem with CAS, it would be error 11.

[GiJOr33]

No i haven't checked those as yet. How would i go about checking those to items you mentioned?

[blind_elk]

Power is supplied to the coilpak, and the ECU earths the coil thru the ignotor to generate spark. Work out which wire is the power at the coilpak - if you pull the plug off and look into the plug, I think it will be the left-hand of the three pins in the plug.

Switch ignition to IGN / ON (not START), then measure voltage to earth (chassis / engine). It should be basically 12V.

If it's not 12V, I really have no idea WHERE the relay is located - it will be up to you to go exploring.

[GiJOr33]

ok cool... thanks for the tip. It's at the mechanics at the moment so i'll word him up on that area to check.

[GiJOr33]

well after spending the whole day on it the mechanic found a few problems and in the end got it running. I'll post up what the problems were when i pick up the car and have a chat to him about it. I think it's going to cost me a hell of a lot though, so i'm not looking forward to the bill!!! And there is a bit more to do tomorrow, chuck it on the dyno and check the fuel ratios etc and just give it an all over check up to make sure everything is in check. At least my HKS computer isn't fried and the motor isn't blown!

so thanks to everyone that gave suggestions on what to check. I tell ya, this whole engine transplant saga has meant i know the RB25 almost backwards now and would be confident to do it again. Just a shame the couple of places i took it to to do the things i couldn't (check A/F ratios and pull out the old motor and drop in the new) did a pretty half assed job job. Oh well... disappointing but i spose once you find a good mechanic you need to stick with them!

Andrew

[GiJOr33]

Yes... the car is all working!!! cost me $670 though... had some cracked wires to the computer. The igniter wasn't grounding properly, the vacuum hose to a map sensor was stuffed... so a few hours spent sorting it out but it's all fixed. Chucked it on the dyno and set the max boost, gave it a quick tune to make sure everything is in check and pulled a nice 222kw at the wheels at 0.68bar (9.8psi)... so i'm pretty happy. All i need to do now is bigger pump and i should be able to get it up to 1.1-1.2bar and have some good power!

Andy

[Sumo]

GiJor: thanks for the heads up man, its always good to read about problems and their solutions.....

Sumo