95 Spyder VR4 Jester Chrome ECU Tuning (weird idle/part throttle behaviour)

[D.I.P.]

Ok today i installed a "Jester Chrome ECU" i bought from 3SX, an AEM TRU Boost and an AEM WideBand. I then flashed the chrome V2 stock rom with the disabled peripheries recommended in the tuning thread here in the forum. The car starts fine and idles fine initially but after a bit it starts to idle a bit funky. Idle drops and vibration goes way up. Then when i try to drive the car under low to medium load let's say anything from 10-70% throttle the car runs like crap the Wideband is pegged lean if i hold the throttle there for a bit and let the rpm come up as i gain speed suddenly the car "jumps" into power/boost (almost like flipping a switch) and runs fine until i let off the gas and do it all over again. Additionally it seems that if i go WOT the condition clears up and the car runs ok, but ONLY while i am at WOT or close to it say anywhere above 80-85% throttle.

The car is basically just a BPU car. It has: No cats, 3" DP, K&N Intake CX Racing Dual Core FMIC, HKS SSQV 4 BOV (Open to atmosphere). Full Vac Reduction, Stock Fuel stock Turbos. The car runs PERFECTLY with this same exact setup on the Stock ECU. The only things that changed were the Chromed ECu and the Boost controller. ( i was running a Blackstealth LCDBC and switched to the AEM TRU BOOST)

Any ideas?

[Chris@Rvengeperformance]

Check the fuel trims

[D.I.P.]

i did a lot of searching last night, both here and on the other forum. I found a couple of threads that seem to describe cars exhibiting very similar symptoms to mine. Where the car seems to run on 3 or 4 cylinders after just a few hundred feet under load. Most of those threads mention that it is possible the Jumpers inside the Jester Chrome ECU could be set incorrectly. Now as far as i know all Spyders are "Cali spec" so i ordered a cali spec ECU from 3SX and the ECU is also clearly marked as a 94-95 VR$ "Cali Spec". The ECU case has warranty seals so i'm not sure i should just tear this thing open without further verification that this is in deed a likely culprit. In most of those threads i saw people suggesting that the front 02 sensor be disabled and to report back on how the car ran after. I tried it this morning and while it did seem to initially idle much better (WB showing almost perfect AFR jumping between 14.5-14.9) The same exact problem persisted once i drove the car around the block. After a couple of hundred ft it felt like i was down cylinders again and it would not run right unless i went WOT.

[D.I.P.]

Check the fuel trims

I logged the car yesterday and unfortunately i don't have the logs with me now (work computer) but i do recall the trims being pegged at -12.5 & +12.5 i just cant remember which was front and which was rear off the top of my head.

[Chris@Rvengeperformance]

yeah your o2's are backwards then.

[D.I.P.]

yeah your o2's are backwards then.

How do i fix that is that a jumper setting in the ECU?

[Jimvr4]

Yes, it is a jumper setting. Seems like almost everyone with Chrome has this issue in the beginning. Can barely runs when in closed loop.

[futurevr4man]

Contact Adam on here (JerstersDeadd) and he will walk you through it. I had to break the seal on mine (with him on the phone) and I ended up swapping it out because I have a 1G wiring harness in my new car now, and there were zero issues. He's a super nice dude.

[striker2]

I thought I remembered reading somewhere that even though the spyders are cali-spec the O2s are wired backwards? can anyone confirm that, and if so that should probably be added all the places that these can be bought.

[D.I.P.]

I thought I remembered reading somewhere that even though the spyders are cali-spec the O2s are wired backwards? can anyone confirm that, and if so that should probably be added all the places that these can be bought.

Which would then mean that specifically for Spyders even though they are Cali-spec cars the Jester ECU Jumpers should be setup for Fed-spec in order to correct for that issue?