Droops83

First, be 100% sure there are no vacuum leaks (smoke test if possible). Then, get your base fuel/VE map in the idle and low RPM/cruise range sorted before messing too much with the idle settings. A fresh valve job will make the cylinders seal better then they did before the job, which changes the VE. Auto-tune is an easy way to get this dialed in quickly.

Also, make sure that the idle contact switch on the TPS is adjusted properly (this can easily be verified in the VEMS software, it will say IDLE ON at the top of the main screen if the contact is closed). If all of the above are OK, then start playing with the specific idle settings.

Cyberpunky

Hi Chris
Thanks for replying. It's fixed(see above as I edited my post)
My mechanic sprayed WD40 to check for vacuum leaks and all was good.
After fixing idle issue by deleting the ICV, I just need to reload(again) the original config Peep supplied with the unit and do a decent autotune. The car is running great and I can't wait to get the autotune done.
Bruce

shortyboy

Still chasing my start issue where I get a good start and bad start ( lots of stumbling at idle and all rpm ranges.) in Vems which sensor is it getting timing from? The speed or reference sensor? My theory is that I have a bad sensor which is why I would need for it crank over a few times to see TDC and have a "good" or normal start. I've tried numerous settings for cranking, afterstart and warm up. Again issue shows up cold or hot engine. Also DME temp sensor comes to mind also. Car runs great on that good start. But if I get a bad start and try to run it, it feels like I'm running very lean, lots of sputtering and back fire. It almost seems like it's loading a different tuning map, like an A, B setting. Also suspecting fuel system, not enough pressure first few cranks. Or injector settings like latency or dead time. Gonna install an 044 soon. Waiting on the adapter.***did tons of reading and im leaning towards fuel system. Either incorrect injector settings like dwell time/latency, voltage drop to fuel pump, bad check valve or even fuel damper. FPR is good as gauge is steady at idle and reads 3bar/43 psi with vac line off.***

Is anyone running delphi low z 55# injectors? If so, case to share your injector settings?

Droops83

Have you logged good and bad running sessions and compared data? It seems that with a running issue this drastic, something obvious will show up in the datalog (AFR, MAP, CLT, MAT, etc).

shortyboy

Hi Chris,

Ive done some short logs as I dont want to run it that long with a bad tune, which it looks like it. It shows lean afr across the board. Also, whenever Im cranking the starter, if rpms on first crank is below 1k, its a bad start, but if it goes past 1k, around 1300rpm it always starts good. But since adjusting injector dead times or latencys, Ive been having good results, car is starting much better and throttle response too. Probably need to adjust it further for cranking at a specific voltage. Still cant find dead times/latency specs for my delphi 55# injectors. Initially VEMS was set to 550cc, where in fact they are 578cc flow rate.

Droops83

I don't see injector latency settings being slightly off as the cause of an intermittent lean running issue. If that were the case, it'd be lean/bad running all of the time. How lean is the AFR when it acts up? If the sputtering/backfiring happens during low speed/low load conditions, I doubt you'll hurt anything.

Are you saying that you see either 1000 or 1300 RPM while the starter is cranking, before the engine starts? That isn't right, starter speed is ~400 RPM at the best of times. Maybe you are having a version of the trigger errors I keep hearing about? Does the engine RPM reading in VEMS seem to correspond with actual RPM? Hook up a digital timing light to a spark plug wire and compare the readings to what VEMS is showing.

shortyboy

It runs lean or rough across all rpms and even after warm up. I've done the VE analysis when it runs rough and it's about 5 - 10points lean. It's very weird. Cause, when I have that "good start ", then shut it off then immediately start it I would have the issue, rough/lean condition. I can see on my windows tablet and tach that rpm matches. If I see the rpm on startup don't pass 1k,i know I will have the bad condition. If it goes past 1k around 1300 it's good and smooth. The car starts before 1k but I'm talking about the needle moving after the engine starts. Next will check timing. Starting to think maybe it's my speed reference sensors. For example, it doesn't see TDC properly and gives the rough condition, then a restart would correct it. I also have a fuel pump waiting for parts to install, maybe a voltage drop at pump on start not supply enough fuel? Would you mind sharing your config, so that I can compare. Maybe a setting I did messed things up or was incorrectly set when it was sent to me. I appreciate your help on this. 🤙🏽I'll post a vid of both conditions and logs.

NCLA951

NCLA951

shortyboy

Req_fuel is set at 8. And lambda for idle is at 1. Here's a video of the conditions.

Droops83

Check your throttle position sensor and throttle cable adjustment. Even with all of the glare and blurriness during the tablet screen shots, I can see that the VEMS cannot tell the TPS is seeing idle; if the idle switch circuit is good, the "IAC ON" icon at the top would light up green at idle with the throttle closed all the way. Therefore it is likely that the idle control valve is sometimes playing a role in the engine running, sometimes not, and could even be sticking open.

If I am totally off base and/or you have deleted the idle control valve (or even if not), the culprit is likely an intermittent vacuum leak. Smoke test the entirety of the intake and boost circuits. Check your bypass/recirc/"blowoff" valve. It could be that it is hanging open intermittently and causing a lean condition.

shortyboy

Real sunny day today, sorry. The tablet connects via Bluetooth and it takes a while to reconnect. I'll recheck my Tps, it's a Ford Tps on a 65mm throttle body and cable tension. If you read back on my old posts this happened also on the stock TB and TPS, I swapped it out hoping to fix. The issue, but it still persists. I've deleted idle control valve and my bov is an Hks ssq that vents to atmosphere. Will pressure test and smoke test vacuum system. Since it's running lean, could it possible be fuel system related? Like a voltage drop causing fuel pump or injectors to run lean? Battery is 5 years old. You can hear it when I'm gonna get a good start/tune cause the engine revs higher. And I've never had this issue on vitesse maf/piggyback setup with an idle control valve. Thanks for your input.

Cyberpunky

I have had same issue since I got VEMS. Usually by second or 3rd start it runs properly. I am wondering if it's either voltage related or maybe sensor gap on speed and ref sensors. Car runs great when it clicks over and is clean. I have 3 br, FPR, 80lb injectors, reasonably new fuel filter, so doubtful it is fuel delivery. I have also removed ICV now, no change, although car idels properly when I get clean start. Nothing I have done has made any difference so have just got used to having to start it a few timees. Very annoying considering how well it runs when its running cleanly

blade7

I may be mistaken, but I think Peep told me VEMS doesn't rely on the idle circuit in the standard TPS.

shortyboy

Surprised to know that someone else with the same issue. What have you done so far to correct issue?I thought about speed reference sensor gap and quality. Then interference and kickback comes to mind. Did you notch the bell housing by any chance or have the older type speed reference sensor bracket without the updated sleeve?I've notch my bell housing when I rebuild my motor a few years back and believe I have the bracket without sleeve.