ManwithSupra Posted October 5, 2018 Share Posted October 5, 2018 (edited) Seems that I have a little AFR Gremlin. Decided to start the car up today to make sure all is well before I take her out in a few weeks. On idle it was running fine but noticed a high fuel smell, looked at the AFR gauge and its realing 10.2 on idle??? Checked the syvecs software where it also shows the same, then it suddenly it jumps to 13.8/14.2 for a few seconds revs increase very slightly (notice a tone change) and then back to 10.2 where it stays for the most of the time... if you pop the revs quickly and let it return to idle sometimes the AFR goes back to high 13's low 14's for a few seconds but then ends up going back to the 10's again. I have looked at the Map sensor when the car is off and its reading 1025mb which is about correct for Atmospheric pressure and when the car is runnig it goes down to around 530 which is about right IIRC with a slight fluctuation with the rev change. Fuel pressure seems ok at just below 40psi, I am really not sure what could be causing the issue. Given the wideband is providing a reading I am guessing its OK... but then it could be failing as its getting on now. Can anyone else suggest anything to check? Edited October 5, 2018 by ManwithSupra (see edit history) Quote Link to comment Share on other sites More sharing options...
pedrosixfour Posted October 5, 2018 Share Posted October 5, 2018 Injectors? Quote Link to comment Share on other sites More sharing options...
ManwithSupra Posted October 5, 2018 Author Share Posted October 5, 2018 (edited) Injectors? What like if one is stuck open? if it was a stuck injector, would my fuel pressure regulator gauge be all over the place? What happens right now is when I switch the ignition on the fuel pumps operate as per normal and the fuel pressure goes up to just below 40psi right away and stays there until the pump switches off, the fuel pressure then tails off as per normal. When the car is running it just sits there at just below 40psi and does not move. If I had a free flowing/intermittant injector then surely I would see more movement on the FPR gauge as it tries to regulate? I hope its not a stuck injector, that is going to be a right pain to sort with the engine position where it is lol Also I dont want to Hydrolock the engine if I do have a stuck open injector. Edited October 5, 2018 by ManwithSupra (see edit history) Quote Link to comment Share on other sites More sharing options...
pedrosixfour Posted October 6, 2018 Share Posted October 6, 2018 Yeah, I was thinking it might, perhaps, be a sticking injector. Not quite stuck open, but not working right either. A delay in closing maybe. Can't you just tell I'm way out of my depth here! I forget, what sort of cold start fuel/ignition management is on these engines? Could it be something like a dodgy sensor keeping the fuelling from successfully switching to the (a) warm engine setting? Quote Link to comment Share on other sites More sharing options...
Mike2JZ Posted October 6, 2018 Share Posted October 6, 2018 Temperature is a bit colder now, maybe your cold start settings need work. See how much fuel is being added when engine is cold, and see as ECT increases if this added fuel tapers off. Normally when an oxygen sensor is on the way out I've seen them either go really erratic on AFR, or they tend to stick really rich or lean and can throw you off. If you have a closed loop AFR system enabled, check to see if its fighting to either add or remove fuel as it's constantly out of range With engine off and ignition on, use Syvecs to test output to each injector. Can you hear each solenoid click? Do a quick test whilst car is idling, choose the cells that are being used and take -15% fuel out. If your AFR dosen't change then you know you probably have a sensor issue. Quote Link to comment Share on other sites More sharing options...
ManwithSupra Posted October 6, 2018 Author Share Posted October 6, 2018 Cheers guys, some things to test there. along with some great info. I will check to see if at least all the injectors are making noise when actuated as suggested as then I will know if there is one which is not responding at all. If there is one that is not responding i'll test the Injector harness plug to see if there is any voltage going to it in case there is an issue with the loom. I will also do the rag test with the AFR sensor. I will update this thread as we go. I will have a good look on Monday. If anyone else has any suggestions please feel free to mention them. Quote Link to comment Share on other sites More sharing options...
ManwithSupra Posted October 8, 2018 Author Share Posted October 8, 2018 So did a quick visual look between calls and noticed that one of the injector plugs is cracked. Not sure if that would cause the issue I am having as if it was an electrical connection issue I thought I would see the opposite (lean) as the injector would not fire... In any case it needs replacing... Anyone have the part number for this plug? And maybe thoughts if this could be the cause of the issue? Planning to do some more tests today on it. The Wideband I have got is proper old now so I am going to replace it anyway as its seen better days. As I do not want to damage the piston rings/cylinders due to borewash I am not going to start the car again until I have sorted that connector and replaced the wideband. Then at least if that has not sorted the issue then I will rip apart the intake remove the injectors and get them cleaned and flow tested as it could only be an injector issue. Quote Link to comment Share on other sites More sharing options...
Mike2JZ Posted October 8, 2018 Share Posted October 8, 2018 I've got loads of spare injector connectors, can send you one if it helps. I can't imagine the outside of the plug connector causing issues, unless it's causing the pins inside to be dislodged, not making contact or both pins contacting each other. Quote Link to comment Share on other sites More sharing options...
ManwithSupra Posted October 8, 2018 Author Share Posted October 8, 2018 I've got loads of spare injector connectors, can send you one if it helps. I can't imagine the outside of the plug connector causing issues, unless it's causing the pins inside to be dislodged, not making contact or both pins contacting each other. Mate, if you have some going spare then that would be awesome. How much would you want for a couple? But yeah thats what I think too, still my with my OCD I wouldnt be able to let that go i'll always be wondering lol Quote Link to comment Share on other sites More sharing options...
Mike2JZ Posted October 8, 2018 Share Posted October 8, 2018 Mate, if you have some going spare then that would be awesome. How much would you want for a couple? Nothing, just cover postage and I can get a few in a small envelope to you. Quote Link to comment Share on other sites More sharing options...
ManwithSupra Posted October 8, 2018 Author Share Posted October 8, 2018 (edited) Nothing, just cover postage and I can get a few in a small envelope to you. Really, you sure mate? thank you what a legend !! PM me your PayPal address and the amount that will cover it and i'll send some money your way. If you cant do paypal send me your bank details instead. Edited October 8, 2018 by ManwithSupra (see edit history) Quote Link to comment Share on other sites More sharing options...
ManwithSupra Posted October 8, 2018 Author Share Posted October 8, 2018 So whipped out the AFR sensor expecting to see a Bosch LSU 4.9 but it turns out to be a LSU 4.2 Done a bit of research on the 4.2 and they are well known for only lasting a couple of years where the LSU 4.9 is supposed to have a service life of +10 years. This 4.2 has been in the car for ast least 7 years, OK not used everyday but this may be the issue we are looking at... it also looks like it has a dent in the top which would indicate its been dropped before...which is never good for a O2 sensor... Quote Link to comment Share on other sites More sharing options...
ManwithSupra Posted October 18, 2018 Author Share Posted October 18, 2018 So Verdict when it comes to the AFR sensor, it was not that. Looked hopeful to start with but then as the engine warmed up it went back to 10's again :-/ The thing is when its trying to correct the afr's and they are around 12-13 its running lumpy as soon as it goes full rich it smooths out. Quote Link to comment Share on other sites More sharing options...
ManwithSupra Posted October 18, 2018 Author Share Posted October 18, 2018 So the strip down starts... going to get the injectors out, tested and then cleaned. Replace all the spark plugs, check the coil packs, get the fuel pressure regulator checked, check the MAP sensor and then replace what needs to be replaced and hopefully we will be back to where we need to be. If its still got high AFR's after all that then I suppose a full remap is on the list of things to do. Quote Link to comment Share on other sites More sharing options...
Swampy442 Posted October 18, 2018 Share Posted October 18, 2018 What AFR gauge are you using? Quote Link to comment Share on other sites More sharing options...
pedrosixfour Posted October 18, 2018 Share Posted October 18, 2018 How old is the fuel Rich? Quote Link to comment Share on other sites More sharing options...
ManwithSupra Posted October 18, 2018 Author Share Posted October 18, 2018 What AFR gauge are you using? AEM gauge, but also the same reading on the syvecs. Quote Link to comment Share on other sites More sharing options...
ManwithSupra Posted October 18, 2018 Author Share Posted October 18, 2018 How old is the fuel Rich? Its pretty fresh Quote Link to comment Share on other sites More sharing options...
pedrosixfour Posted October 18, 2018 Share Posted October 18, 2018 Its pretty fresh Carry on! Quote Link to comment Share on other sites More sharing options...
Swampy442 Posted October 18, 2018 Share Posted October 18, 2018 And are you using the AEM as a simulated narrowband? Quote Link to comment Share on other sites More sharing options...
bignum Posted October 18, 2018 Share Posted October 18, 2018 Have you checked the engine temp sensor? Quote Link to comment Share on other sites More sharing options...
ManwithSupra Posted October 18, 2018 Author Share Posted October 18, 2018 (edited) And are you using the AEM as a simulated narrowband? I am not sure, how would I check that? Is there something to look at in SCAL to determine this? - - - Updated - - - Have you checked the engine temp sensor? Yeah engine temp sensor is working fine. I assume you mean coolant temp sensor. Edited October 18, 2018 by ManwithSupra (see edit history) Quote Link to comment Share on other sites More sharing options...
ManwithSupra Posted October 18, 2018 Author Share Posted October 18, 2018 How old is the fuel Rich? This has actually got me thinking, if I have a bad batch of fuel would it cause this issue? I wonder if I should drain and replace with some fresh v-power just to make sure. Quote Link to comment Share on other sites More sharing options...
Mike2JZ Posted October 18, 2018 Share Posted October 18, 2018 Can you post a log from your Syvecs showing the warm up before going rich? Quote Link to comment Share on other sites More sharing options...
ManwithSupra Posted October 18, 2018 Author Share Posted October 18, 2018 Can you post a log from your Syvecs showing the warm up before going rich? Can do, I will upload it when I am at the workshop tomorrow. Quote Link to comment Share on other sites More sharing options...
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