Car only goes up to 3k rpm??

[James_S15]

Hiya,

Got a weird problem after just getting a H-Dev 1a ECU installed (brand new chip/board)...

The car now only boosts to 3k rpm. Doesn't matter what gear I'm in when I hit 3k revs it just stops revving and is like hitting a brick wall?!

Anyone experienced this problem at all?

Cheers - J

[James_S15]

Sorry meant to say car only drives up to 3k revs. Boost only goes up to about 0.2 bar WTF??

And yes I've check my boost controller settings. They're the same as before I got the ECU upgraded and she was driving 1 bar all day!!

[rb30s14a]

You running AFM ?

[sideways14a]

Sure the chips installed properly?
Any of the boost pipes been disturbed?

[mpig]

Sounds afm/boost related mate, unplug the afm and see if its the same?

[James_S15]

Just stock AFM dude. Everything plugged in ok.

Yeah checked all boost pipes they're fine as I can tell.

I'm gonna get ECU checked over again and maybe try another unit because my mapped told me when he took it apart, the previous owner had obviously installed similar thing before as there was crap and left over solder inside?!

The more I work on the car the more I'm getting fed up of the pikey shite the previous owner has done to this car grrr!!!!!

[James_S15]

*mapper*

[James_S15]

Sounds afm/boost related mate, unplug the afm and see if its the same?

I'll deffo unplug the AFM and see if anything's different. Ta

[HermaN]

Is the engine management light on and can your mapper connect to the ECU with their laptop? If the CEL is on and they can not connect then the ECU is in limp home mode. Clearing up any solder splatter and re-fitting properly might help unless it has been perminantly damaged.

However limp home mode usually limits you to 2000 RPM.

[Chriscooke]

Who fitted the chip? This is why I sent mine to hdev tbh as I knew it would be right.

Just encase its unrelated to the chip does it rev normally when in neutral (off load)?

[James_S15]

Thanks for the replies fellas...


Ok I've spoken to my mapper this morning and there's definitely no issue with how he's fitted the H-Dev chip as I know for sure he's done about 40 - 50 of Jez's chips now. Incidentally, he deals directly with Jez and also contacted Jez to find out what could be the problem. I'm also unconvinced there's a problem with the chip/board itself as they have an excellent history and my mapper has never had one which has failed!

It's definitely in limp mode as the ECU check light is on (although it did do this before I got the H-Dev chip fitted). I don't even remember whether it goes past 3k revs when in neutral lol Definitely did it in all gears I tested.


I'm going to give the AFM a clean tonight with contact cleaner and see if this helps. Will also try letting the ECU 'learn' by turning the key to on position for 30 secs then turn off. Then start the car and let it idle for a few mins. Believe the main issue now is that I've had a dodge AFM which the previous stock ECU learned to get around (although as some people know it was smoking heavily at Japfest so it was never quite right!). If the contact cleaner doesn't work I'll try a replacement AFM. If this still doesn't work then I know the ECU must be goosed and will try a replacement ECU (and if this ECU works I'll then get the chip moved over to this unit).


BTW - if I have to replace my ECU and try another unit can I ask whether:

1. There will be an issue with NATS as I believe the chip in the key matches a code on the ECU?

2. Does it have to be an ECU very specific to the S14a? Also are there different versions to the 14a ECU?


Cheers all

[Mattie]

If it comes to it mate, I've got my old AFM i've taken off to replace with the Z32 & I've got a spare 1a chip too...

[HermaN]

First thing is process of elimination. Remove the chip from the ECU, swap the jumper back and revert the ECU to stock. Test it again, if it still does it, I would suggest trying a different ECU. If the car runs fine with the ECU reverted back to stock then get it fitted again and test, it could be a tiny spec of solder causing a short and removing, then re-fitting will result in connections being cleaned and possibly fixing the issue.

If it works fine with the ECU reverted to stock, but does not work after re-fitting the daughterboard, then there is a fault with the board itself, possibly a damaged EPROM, corrupt data (has it been sitting in the sun?) or even a faulty/damaged board. If the ECU can not run the code from the daughterboard it will revert to the internal limp processor.

Actually, an easier/quicker way to test would be to simply get the mapper to swap the jumper on the ECU over so it is reading off the internal processor and running a stock map. If it still does it, then try to remove/refit, if moving the jumper position gets it out of limp mode then the daughterboard/EPROMs are the culprit as when the jumper is put back into the stock position the daughterboard is not being used.

NATS on a new ECU can be sorted with NATSynch and most 8xFxx ECU's will work fine on an S14a, but be careful, some of the very early 14a's have the same connector as the 14's, but most S14a's have the later connector.

However a faulty MAF or other sensor can also put it into limp mode, but if it only happened after the board was fitted I doubt it would be a sensor issue.

[clive12155]

Ecu knackered mate

[James_S15]

If it comes to it mate, I've got my old AFM i've taken off to replace with the Z32 & I've got a spare 1a chip too...

Thanks dude Might take it off you so will be in touch (obviously let me know what you want for it).


Cheers HermaN - I'm gonna get the car up to the mapper on Friday so we can go through the process of elimination as he can help me set the ECU back to stock and we'll see if this gets rid of the issue!!


I'm still not convinced my AFM is working correctly. And when I looked to use some electrical contact cleaner on the unit, I couldn't see the wire which I always thought is 'down the opening' as per pic below:




Should there be a wire you can see through the hole? Sorry if this is a dumbass question but I don't know much about AFM's Well there certainly isn't a wire and I took the screws out thinking you have to remove the plastic part at the top where the harness connects but this doesn't seem to pull apart??

More pics:








Can someone also just confirm the wiring to the AFM is ok? Yes it's dodgy and I'm gonna re-wire and insulate soon... previous owner had fecked around and done something pikey with it!!!


Cheers

[James_S15]

^^ Ignore me on my questions about the AFM above, I've found all the answers here:

http://www.sxoc.com/vbb/showthread.p...lean-your-AFMs


Gonna give this a go now!!

[James_S15]

*AFM VOLTAGE*

Does anyone know what voltages the AFM wires should be (on stock S14a AFM)??

I measured them today and:

BLACK & WHITE = 14.4V
WHITE = 1.4V


Incidentally I've swapped the AFM now for another stock one (thanks Mattie!) but it's not got it out of limp mode However, the WHITE wire for the AFM has suddently completely broken itself off at the harness plug end so more soldering to do and try again grrr!!!!!!

[JC SX]

Did you modify the timing for the chip? Jez when he fits it retards the timing to suit it
I'd call him, he's very friendly and will talk you through your issue

[James_S15]

Did you modify the timing for the chip? Jez when he fits it retards the timing to suit it
I'd call him, he's very friendly and will talk you through your issue

I haven't modified the timing dude but it's not something I believe you need to do AFAIK?? I've never heard of anyone having their timing retarded after getting a 1a chip installed


My mapper has been in discussions with Jez so I'm getting good advice... in my mind this is definitely a problem relating to either:

1. AFM dodgy wiring (because the white wire has just broken off today - believe this is the signal wire for the AFM)
2. ECU faulty (because my mapper told me it was in a shocking state when he went to fit the H-Dev board)
3. Daughter board faulty
4. Stage 1a chip faulty


If fixing AFM wiring does not change things then it's time to put the ECU back to stock (moving the jumper) and start from there At least my mate Mattie has kindly offered me his spare 1a chip to test with and eliminate the fact that it could be a faulty chip I've got installed *very unlikely because all H-Dev parts are brand new*

[JayS15]

h-dev chips are basicly the same as NIStune right? when i had mine fitted, the chip was corrupted with bad data. apparently there was a batch that was bad. got sent a replacement by h-dev and problem solved...