carl0s Posted October 11, 2009 Author Share Posted October 11, 2009 Compression test shows (front to rear): 170,170,170,170,175,170 I'm thinking they're pretty reasonable numbers. Only thing is, I forgot to warm the engine up to operating temp first, so those numbers are with a relatively cold engine Quote Link to comment Share on other sites More sharing options...
pistonbroke Posted October 11, 2009 Share Posted October 11, 2009 They look fine to me. Quote Link to comment Share on other sites More sharing options...
TLicense Posted October 11, 2009 Share Posted October 11, 2009 Agreed. Hot or cold as long as the pressure is within 5-10 psi you're all good. Quote Link to comment Share on other sites More sharing options...
carl0s Posted October 11, 2009 Author Share Posted October 11, 2009 OK thanks. Could low coolant kill the coolant temp sensor? Coolant was a little low. I was clinging onto the hope that low coolant might cause erroneous readings on the coolant temp sensor, so I topped up, drove fine until almost home after the 15 minute drive and then it's doing the same again. Quote Link to comment Share on other sites More sharing options...
Steve Posted October 11, 2009 Share Posted October 11, 2009 Have you considered doing a refurb of all the electrical connectors? Quote Link to comment Share on other sites More sharing options...
carl0s Posted October 11, 2009 Author Share Posted October 11, 2009 Have you considered doing a refurb of all the electrical connectors? No. Don't fancy that to be honest. There is one that looks a little fubar'd though, and it's the one that Luigi stuck a photo up of (not sure why he photo'd it yet or if that's the one that fixed his problem). This one on top with the rubber boot here: http://mkivsupra.net/vbb/attachment.php?attachmentid=99727&d=1255174686 Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted October 11, 2009 Share Posted October 11, 2009 If you have a Calor or Propane gas bottle and regulator make up a long hose with a bit of bent metal brake pipe shoved in the end and spray the gas around the injectors and intake manifold et cetera, the engine RPM and note will change markedly if there's a leak and the gas is sucked into it. Don't set yourself alight! Quote Link to comment Share on other sites More sharing options...
carl0s Posted October 11, 2009 Author Share Posted October 11, 2009 If you have a Calor or Propane gas bottle and regulator make up a long hose with a bit of bent metal brake pipe shoved in the end and spray the gas around the injectors and intake manifold et cetera, the engine RPM and note will change markedly if there's a leak and the gas is sucked into it. Don't set yourself alight! That's a clever idea. What about if I get a can of EZ-Start and spray that around the areas in case I can't find any propane? Quote Link to comment Share on other sites More sharing options...
Guest Luigi Posted October 12, 2009 Share Posted October 12, 2009 There is one that looks a little fubar'd though, and it's the one that Luigi stuck a photo up of Erm, yup my bad. /vbb/images/smilies/bbcode_oops.gif I called it the ICV. Thats the IACV VSV (Intake air control) and that is the one I cleaned up. Been idling fine since though, but now I cant see why it should. Also that connector had a broken bit with some or the wire terminal exposed. Quote Link to comment Share on other sites More sharing options...
carl0s Posted October 12, 2009 Author Share Posted October 12, 2009 Erm, yup my bad. /vbb/images/smilies/bbcode_oops.gif I called it the ICV. Thats the IACV VSV (Intake air control) and that is the one I cleaned up. Been idling fine since though, but now I cant see why it should. Also that connector had a broken bit with some or the wire terminal exposed. My connector is broken too. What did you clean up? You're gonna run out of posting ability soon so tell me how to fix it Quote Link to comment Share on other sites More sharing options...
Steve Posted October 12, 2009 Share Posted October 12, 2009 Carl, posted the water temp sensor Quote Link to comment Share on other sites More sharing options...
carl0s Posted October 12, 2009 Author Share Posted October 12, 2009 Carl, posted the water temp sensor Thanks very much Steve! Between the coolant temp sensor, throttle body, plenum & most sensors, ECU to try out, I reckon I'm gonna get this nailed soon Quote Link to comment Share on other sites More sharing options...
Ian C Posted October 13, 2009 Share Posted October 13, 2009 Here's a thought. Take the big black pipe off the idle control valve's air intake. Start the engine. Block the intake off. If it doesn't stall, you've got an air leak somewhere. I sometimes forget to reattach the PAs bypass hose, resulting in a high idle but no stalling issues. You've got some contradictory symptoms there, usually a high idle means it's harder to stall... -Ian Quote Link to comment Share on other sites More sharing options...
carl0s Posted October 13, 2009 Author Share Posted October 13, 2009 Here's a thought. Take the big black pipe off the idle control valve's air intake. Start the engine. Block the intake off. If it doesn't stall, you've got an air leak somewhere. I sometimes forget to reattach the PAs bypass hose, resulting in a high idle but no stalling issues. You've got some contradictory symptoms there, usually a high idle means it's harder to stall... -Ian That's the thing. It's fine one minute, then it's hesitating when leaving idle (nearly stalls when hitting throttle, and when lifting off the rev counter drops too far then bounces back up, so you have this springy bouncy idle when cruising), then other times it idles at ~2k. More often than not the problem is the hesitating off idle when hitting throttle. The high idle is a less common symptom. If it stalls from the hesitating, it's often difficult to re-start and can take a while. having to be left for 5 minutes. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted October 13, 2009 Share Posted October 13, 2009 Has it got a new O2 sensor fitted, or 2 of them if it's a UK car? Quote Link to comment Share on other sites More sharing options...
Ian C Posted October 13, 2009 Share Posted October 13, 2009 My money is on overfuelling - have you checked the voltage at the diag port when warm idling? Quote Link to comment Share on other sites More sharing options...
carl0s Posted October 13, 2009 Author Share Posted October 13, 2009 Has it got a new O2 sensor fitted, or 2 of them if it's a UK car? No. If the stuff I'm about to swap doesn't do it, I'll try an o2 sensor next. I cleaned the existing sensor, although it didn't look too bad anyway. My money is on overfuelling - have you checked the voltage at the diag port when warm idling? No I haven't. I'll have to look up how to do that and what voltages I should be expecting. I do have CJs service manuals somewhere, but I'm just not sure where they are since I moved to my gran's house Quote Link to comment Share on other sites More sharing options...
Terminator Posted October 13, 2009 Share Posted October 13, 2009 I think I have my old O2 somewhere. Using AEM sensor now. Quote Link to comment Share on other sites More sharing options...
carl0s Posted October 13, 2009 Author Share Posted October 13, 2009 I think I have my old O2 somewhere. Using AEM sensor now. Oooh I'll have almost a whole car off you soon Phil Quote Link to comment Share on other sites More sharing options...
Terminator Posted October 13, 2009 Share Posted October 13, 2009 I would go with Ian's suggestion, over fuelling fits with the poor restart, waiting for the soaked plugs to work properly again. You really want a known good O2 sensor not a second hand one, if that may be the problem. Quote Link to comment Share on other sites More sharing options...
carl0s Posted October 13, 2009 Author Share Posted October 13, 2009 (edited) I would go with Ian's suggestion, over fuelling fits with the poor restart, waiting for the soaked plugs to work properly again. You really want a known good O2 sensor not a second hand one, if that may be the problem. I'd kind of still been thinking that the poor start is due to the ICV being all the way in, when it should be out a bit, but I guess it might not be.. I'll have to search for the diag stuff then. Is it on here somewhere? Edited October 13, 2009 by carl0s (see edit history) Quote Link to comment Share on other sites More sharing options...
carl0s Posted October 13, 2009 Author Share Posted October 13, 2009 My money is on overfuelling - have you checked the voltage at the diag port when warm idling? What'm I checking the voltage of Ian - o2 or something? Quote Link to comment Share on other sites More sharing options...
Ian C Posted October 14, 2009 Share Posted October 14, 2009 What'm I checking the voltage of Ian - o2 or something? The Ox1 pin. It should bounce around 0.5v. http://www.mkivsupra.net/vbb/showthread.php?t=35940 "Diagnostic port reading procedure: Your diagnostic port is a small black box on the side of the intake, with "diag" written on the flippy top lid. Put the negative probe on the battery ground and the positive probe on the pin OX1 (the pins are labelled on the underside of the flippy lid). You should see, at warm idle, a hunt between 0.5v and 0.7v. Any solid figure between 0.8 and 1.0v is running too rich and the ECU can't compensate. Any solid figure under 0.4v means it's running too lean and the ECU can't compensate. " Quote Link to comment Share on other sites More sharing options...
carl0s Posted October 19, 2009 Author Share Posted October 19, 2009 (edited) The Ox1 pin. It should bounce around 0.5v. http://www.mkivsupra.net/vbb/showthread.php?t=35940 "Diagnostic port reading procedure: Your diagnostic port is a small black box on the side of the intake, with "diag" written on the flippy top lid. Put the negative probe on the battery ground and the positive probe on the pin OX1 (the pins are labelled on the underside of the flippy lid). You should see, at warm idle, a hunt between 0.5v and 0.7v. Any solid figure between 0.8 and 1.0v is running too rich and the ECU can't compensate. Any solid figure under 0.4v means it's running too lean and the ECU can't compensate. " Sorry Ian, thanks for taking the time to reply. I didn't catch your reply for some reason. I don't want to tempt fate by saying that the problem is fixed, but I do actually think it's fixed now, and after swapping/buying/fixing: New Throttle Pos. Sens (£90) ICV (£65) Intake plenum, throttle body etc, with throttle control motors and throttle pos sens etc. (£70) Noticing and fixing a slight leak in a hose Cleaning O2 sensor overnight in carb cleaner Doing compression test Resetting ECU Removing Thor FCD Borrowing another ECU (didn't actually try that in the end) Well, it turns out to be the coolant temp sensor. I can only imagine that the ECU thought the engine was cold when it was hot, or vice versa ? I hope I haven't cursed it now by saying this, but I drove to Morcambe (60 miles) on Saturday, and drove around locally on Saturday too, and Sunday, and I drove to work today as well, and it hasn't played up once, not even slightly. Usually I would have encountered the problem in about the second warm startup of the car, e.g. after arriving somewhere, staying for a bit and then starting the car again to leave. It's been great, fabulous even. I'm wondering if I really have to get rid .. especially as this chick that I picked up said it's a shame I'm selling it 'cause she really likes it Edited October 19, 2009 by carl0s (see edit history) Quote Link to comment Share on other sites More sharing options...
Steve Posted October 19, 2009 Share Posted October 19, 2009 Quote Link to comment Share on other sites More sharing options...
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