JonM Posted June 17, 2021 Report Share Posted June 17, 2021 Hi guys. I recently put a G4X into a Mazda GTR. The engine is based on the MX5 1.8 so the MX5 map has been loaded Map is MX5 7 bar map using a 7 bar map sensor I've connected MAP and link IAT Changed fuel pump to injector three and have at least 3 second prime as set under fuel pump settings Attempting to assign aux 5 to fuel pres. Reg. Sol. But I can't find it listed although testing aux 5 does activate the selonoid for the fuel rail pressure valve. Changed ignition mode to distributor and only using ignition 1 output (ignition 2 is set to boost selonoid) Engine is generally a complete none starter. On turnover and fuel pump prime it occasionally fires on 1/2 cylinders then nothing. Oddly sometimes on ignition it ignites unburnt fuel in a cylinder also Quote Link to comment Share on other sites More sharing options...
Vaughan Posted June 17, 2021 Report Share Posted June 17, 2021 If you want to use the fuel pressure regulator solenoid you can setup Aux 5 as a GP Output with the conditions you want to activate that solenoid. Have you checked your timing with a timing light? Quote Link to comment Share on other sites More sharing options...
Adamw Posted June 17, 2021 Report Share Posted June 17, 2021 I would suggest doing a triggerscope while cranking too, there was another user on here a little while ago that I helped with a GTX or GTR with similar symptoms and it had a different trigger pattern than the MX5, from memory only a single slot on trig 2 so needed to use multitooth mode. Quote Link to comment Share on other sites More sharing options...
JonM Posted June 18, 2021 Author Report Share Posted June 18, 2021 I can assign GP output to AUX 5 but have no idea on settings to use. I'm stuck in the situation of can't track my timing light down but don't really want to pay for another but regardless if it fires on only 2 cylinders then does nothing afterwards it's not a timing issue right now I already did a triggerscope Quote Link to comment Share on other sites More sharing options...
Adamw Posted June 18, 2021 Report Share Posted June 18, 2021 I wouldn't bother with the fuel press solenoid, the factory ecu just increased fuel press for hot restarts, not 100% sure what for -maybe to eliminate vapour lock or something but I have never had a car that needed it. 6 hours ago, JonM said: I already did a triggerscope Please attach it then. Quote Link to comment Share on other sites More sharing options...
JonM Posted March 18 Author Report Share Posted March 18 OK, It's 3 years later and i've got time to do this again and i still haven't worked out what is wrong Quote Link to comment Share on other sites More sharing options...
JonM Posted March 18 Author Report Share Posted March 18 OK it starts, but stalls after a few seconds and can't be revved, i think it's the fuel pump not pressurising the line? Quote Link to comment Share on other sites More sharing options...
koracing Posted March 18 Report Share Posted March 18 The Fuel pump triggering on the MX5 is done via the air flow meter if memory serves - so usually the relay requires some wiring modification to give ecu control. I would try firing with the air flow meter in place or place a mechanical gauge on your fuel system to check pressure while trying to run to see if it is maintaining pressure or not when trying to run. Also attaching the actual files like a datalog or trigger scope and your current tune (not just screen shot images) would be much more useful, just FYI. Quote Link to comment Share on other sites More sharing options...
JonM Posted March 18 Author Report Share Posted March 18 If I put a live to the fuel pump the car runs, the pump is on DI4which only powers the fuel pump, but DI4 is set to start position and primes it and I can't seem to assign fuel pump to it. I can unassign start position from DI4 but there's no option to assign it to fuel pump. So instead i'd have to wire the fuel pump to an Aux so the ECU can power the pump? Quote Link to comment Share on other sites More sharing options...
koracing Posted March 18 Report Share Posted March 18 DI stands for Digital Input. An input has no way to control an output and is only looking at what comes in. Yes you would have to wire an Aux output to control a relay for the fuel pump. Quote Link to comment Share on other sites More sharing options...
JonM Posted March 18 Author Report Share Posted March 18 Right ok thanks. Hmmm it turns out the fuel pump does activate if i press throttle? I can hear the relay kicking in and out, i don't remember hearing it sound like it sounds though, it's almost flickering on/off, if i hold the throttle in the same place the revs continuously hunt and if i drop to idle it stops kicking in and the car stalls, it also sounds very misfirey too when revving and strongly smells of fuel 323GTR.pclx Quote Link to comment Share on other sites More sharing options...
Adamw Posted March 19 Report Share Posted March 19 You have injection mode set to sequential but the injectors in a GTR/GTX are only wired in two groups. Inj 3 is the fuel pump relay. Aux 3 is the low speed resistor bypass. Correct setup should be something like below for this car with stock wiring. Quote Link to comment Share on other sites More sharing options...
JonM Posted March 19 Author Report Share Posted March 19 Ah Legend. I got the injector grouping figured but I would have never got the high/low fuel pump working The car idles, revs smoothly between 1000-3000RPM, but misfires above that and won't rev any higher, then when I let off throttle revs will drop right down the nearly stalling before recovering after a few seconds? Is this simply because not enough data has been collected for the mixture map and a quick tune will fix it? or is there a bigger issue? PC Datalog - 2024-03-19 3;52;26 pm.llgx Quote Link to comment Share on other sites More sharing options...
koracing Posted March 19 Report Share Posted March 19 Normally increasing base throttle position or adding idle air bypass via a bypass screw if equipped will help prevent stalling. Dashpot settings are also there to help with this. It appears your idle base position is set to zero also which isn't helping. So most likely your at the point that it just needs tuning. You also have no lambda data so that might also help in the effort to tune the car. Quote Link to comment Share on other sites More sharing options...
JonM Posted March 20 Author Report Share Posted March 20 OK thanks for the reply I'm running a standard lambda connected to an volt 2. I'm unsure if I have an issue or whether this is the process, it says Lambda connected but when pressing autotune it flickers between attempting to tune and no WB signal detected, also lambda 1 on the "gauge" flickers between zero and well atm the moment 0.7 underfueling. Pressing throttle seems to make the signal more reliable, to me this suggests my lambda is faulty? or is there something i'm missing?? Also am I required to run a MAF? I wired the IAT and have onboard MAP sensor, am I safe to turn MAF off? 323GTR.pclx Quote Link to comment Share on other sites More sharing options...
koracing Posted March 20 Report Share Posted March 20 What wideband are you using? You aren't going to be able to tune with mixture map and autotune with a 0-1v narrow band o2. Lambda 1 in this most recent tune is set to AN Volt 2, but there is no calibration on it. In the previous log you posted the voltage on AN Volt 2 varies between .235 Volts and .682 Volts so that is not a wideband signal , or at the very least highly unlikely to be a wideband 0-5V signal (possibly a simulated narrow band output signal?). Do you have a gauge on your wideband? What is it displaying? Quote Link to comment Share on other sites More sharing options...
JonM Posted March 20 Author Report Share Posted March 20 Nothing but standard 3 pin OEM Lambda. The gauge I'm talking about is the one displayed in the Link application so I guess I'd need to pick up a wideband, but my main concern is the base map should be good enough to run the engine reliably? But it's pretty horrible, anything over 3000rpm results in misfiring and it won't even rev over 4000rpm. I doubt this would be able to pull it's own weight Quote Link to comment Share on other sites More sharing options...
koracing Posted March 20 Report Share Posted March 20 No, the link base maps are intended to get the car running only which has been accomplished here. Beyond that it will require tuning with a wideband. Some base maps are better than others, but none should be treated as "load it and drive the car" type of maps in my experience. Quote Link to comment Share on other sites More sharing options...
JonM Posted March 20 Author Report Share Posted March 20 Ah OK, I misunderstood, I was under the assumption the maps were designed to run and be safe enough to drive to be mapped properly. So If i pick up an LC-1 sensor it should largely fix the misfiring issues, https://www.ebay.co.uk/itm/166455744865?itmmeta=01HSEEM7AGJJXYTBPE7H79JV2B&hash=item26c1891961:g:ZwMAAOSwRy9lQlA0&itmprp=enc%3AAQAJAAAA8E9fjLkbKjW%2F4vViSZDLPX2kk%2BL6IhiRtaOWHnbSLy%2FH1chJklF6dZ3t4qSBxNVxR3C7t9lZeMESgbnvnP2xMSVFd9Ayi6KcI6UEQXYv7VW66jnuu7aFpalubShjoba1UcSdn2jy%2FHmayBn0taK4sXu7diSagg8nWiffR051x3TF6JJ5x0MOmaTHp04t4uTRir70HcGsVLbbmINZ%2B1tNKyyIkGlIl2Z6Uz0668IIJ7lKCgS6c%2BbakuBnyXDoVcr7RtJowTwS9dNOMOhkyliLmaekfgPHEtBGzlu8bC4etGVFoirL913SPdBGrpNumoQ5qQ%3D%3D|tkp%3ABk9SR6z10M7LYw along with connector https://www.ebay.co.uk/itm/274737911825?itmmeta=01HSEF2J2D0S7F7RPX52M99SK9&hash=item3ff7a7d811:g:b40AAOSw3t9gYbiA&itmprp=enc%3AAQAJAAAAwKxhcWowObXg0wKfHM106e%2FchyCwplhWO0Z%2F396LC%2B%2Bdafp%2FRTrClObmjsEko5hMHqbYP0gv7wAXIyZ%2FWNVfg%2Bu68rXUZRVJYwcu2eI04p3y7Hlw9uQ57f%2BuiSQN33J6hc9WuB5dOSGC4wTuhH5QogRVq23%2BEGiu%2Flwb1hGJXu9ROKfgLfrOgFr3v9TyFgFurggbturLOL2TM13WCrfFr6cdm1LzEAHofLlOGt%2F5pil7lvq9dU%2BiDNQnYv6c76Ym5Q%3D%3D|tkp%3ABk9SR8Chis_LYw Are there any wiring diagrams for 3 to 5 wire sensors? I'm also seeing I might need to buy the wideband CAN controller? Quote Link to comment Share on other sites More sharing options...
Vaughan Posted March 20 Report Share Posted March 20 You'll need a controller for the wideband and most modern controllers use the LSU4.9 sensor. Try and get a wideband controller with a CAN connection if possible as this is much more reliable and has a higher resolution than using a 0-5V analog signal which are often affected by ground offsets and electrical noise. Quote Link to comment Share on other sites More sharing options...
koracing Posted March 20 Report Share Posted March 20 I recommend the AEM X-Series 30-0310 inline wideband controller with CAN connectivity or the Link CAN Lambda wideband systems. Quote Link to comment Share on other sites More sharing options...
JonM Posted March 20 Author Report Share Posted March 20 Awesome thanks for the recommendation and help. This is the unit i'm needing? there's two very similar name and part no's, the 30-0300 unit which comes with a gauge and looks to be the 0-5V analog output I shouldn't bother with, and this one without gauge but the same price that seems to be made exactly for the job? https://www.demon-tweeks.com/uk/aem-x-series-in-line-electronics-wideband-uego-air-fuel-controller-aem30-0310/ EDIT Nevermind I went and bought it anyway, i figured it was right. My old lambda has 2 heater +/- (white) and signal (black) I'm guessing white analog + > (white) brown analog - > (white) Blue serial > (black) AEMnet +/- not used? Quote Link to comment Share on other sites More sharing options...
Laminar Posted March 21 Report Share Posted March 21 Don't use the analog signal, use AEMnet. Higher resolution, not affected by noise, saves your analog input for something else. Quote Link to comment Share on other sites More sharing options...
JonM Posted March 21 Author Report Share Posted March 21 Ah OK I thought the analog would just be switched to digital on the ECU side. So leave the old lambda wiring as it is and use the CAN1 connector (green/black) AEMnet -/ CANL > CAN1 L (white/black) AEMnet +/ CANH > CAN1 H (blue) serial TX > RS232-TX white + brown > analog signal don't bother connecting red + black > ignition live and earth Quote Link to comment Share on other sites More sharing options...
dx4picco Posted March 21 Report Share Posted March 21 Blue serial TX not needed Leave it unconnected Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.