P38 on Zavoli, cold changeover problems.

Message

nick_haynes · #21 Post by **nick_haynes** » Tue Dec 19, 2006 6:44 pm

Good evening, it is indeed fixed. (well for today at least). It would appear that it was the gas temp sensor giving a false reading to the gas ecu. It was situated in the injector block which is why it would work after a little stand as the engine would warm it up, so we have disconnected the old one and fitted a new inline gas temp sensor, which so far has changed every time we have tried it when cold but, the acid test will be tomorrow morning after it has been stood outside overnight. Will let you know what happens. Merry Blinkin Christmas, Nick.

volvo940 · #22 Post by **volvo940** » Tue Dec 19, 2006 8:33 pm

gas temp or do you mean pressure sensor?

nick_haynes · #23 Post by **nick_haynes** » Wed Dec 20, 2006 1:08 pm

Hello Peter. It was the gas temprature sensor, but true to form, having changed over three times yesterday when normally it would'nt have, today on the way to work it would not, even though i left it until it was warmer (on the car temp gauge) than yesterday when it was quite happy to. I tried to do it twice, it tried to cut out twice. "Good lord" i said. When i got to work i left the car for about twenty mins, went back to move it to get the van out and out of curiosity flicked to auto change over, revved it and over it went beautifully, even though the car guage said it was cooler than when i let it try on the way to work. Going back tomorrow to change the ECU. Will let you know what happens. Bah Humbug !! Nick

volvo940 · #24 Post by **volvo940** » Wed Dec 20, 2006 4:28 pm

I'm getting confused here, how is a temperature sensor on the injector block affecting change over? could the wires to the vap and the injector block sensors have been mixed up? PS: if you're going to try swapping them, have someone setup a video camera, preferably with sound!!! Peter

nick_haynes · #25 Post by **nick_haynes** » Wed Dec 20, 2006 7:38 pm

Hello Peter. I don't know, if it has no affect why bother putting it on, i can only assume that it helps the ecu monitor things better. I've checked the wiring diagram for the system against the car and it is wired correctly and, if i had picked up your message earlier about the swap i would tried it out but i only have to wait till tomorrow for it to go back to the installers when i will mention it to him and see what he thinks. This was as far as i had got in this message before i had to go out to deliver some Christmas cards and before i went out i had typed how much perkier the performance was on gas, and how much more torque there seemed to be with the new gas temp sensor. Well you can scrap that because while i was out i had cause to put my foot down and it turned off the gas and went back to petrol. As soon as i turned the ignition off it was fine, until i used the kickdown again and now its all lumpy. Could the sports mode confuse my ecu for the gas and does any one know if like computers these ecu's have a small battery backup, because it seems to me that mine is completely confused. The temp here in Dudley is around 2 degrees if anyone thinks that is relevant, and of course it runs fine on petrol, even when you plant the throttle. Anyway as i say the car is going in to the installers tomorrow who say's he will fit a new ecu and remap it so we will see what happens then. Any comments most welcome. Cheers Nick.

nick_haynes · #26 Post by **nick_haynes** » Thu Dec 21, 2006 1:09 pm

Hello everybody, (anybody?). Could'nt take the car today, installer to busy so i'm going to try swapping over the sensor wires in a while and will let you know what happens. Cheers Nick.

nick_haynes · #27 Post by **nick_haynes** » Thu Dec 21, 2006 1:41 pm

Hello. It just does not change over at all, how ever many you connect or not. Cheers nick

nick_haynes · #28 Post by **nick_haynes** » Thu Dec 21, 2006 6:10 pm

Good evening all. This afternoon i phoned rpi who supplied my engine, told them the issues and the chap i spoke to said that yes it would degrade, he's never got his to change over when cold, and his also did cut out if he used large throttle movements, but only in the winter. His advice was make sure i fit magnecore (right spelling?) leads and open plugs up by an extra 5 thou and this should help improve matters. What does anyone think of this especially the no hope of changeover etc, as i dont know of anyone else with a Zavoli system. Cheers, Nick.

nick_haynes · #29 Post by **nick_haynes** » Fri Dec 29, 2006 11:18 pm

Hello all, hope Santa was kind. Have fitted new vaporisor to car which has turned the performance on gas to that of a missile, or as my friend said, "This goes like a scolded cat!" It has cured the problem of the falling gas pressure which resulted in the change back to petrol when driving so i'm going to strip the old vaporisor to see if it is full of rubbish stopping the diaphragm from moving. I have a plan to see wether or not the injectors are still sticking and will post my results. Have fantastic new year. Cheers Nick.

nick_haynes · #30 Post by **nick_haynes** » Sun Dec 31, 2006 2:55 pm

Hello all. I am happy to inform you all that i have fixed my problem, (small puase while i run round and whoop and stuff). The old vaporisor was indeed full of the 'orrible black goo from the gas and the main diaphragm was pretty limited in it's movement, coupled with the notchy movement on the gas inlet i think that this was my problem as far as the acceleration and reverting back to petrol was concerned. It was confirmed when Tony and i went around the block with his laptop plugged in and it showed the preesure dissapearing every time i stuck my foot down. Stuck the 300 hp vaporisor on, set it to super mode, FANTASTIC!. I went back to talk to Tony about the possability of fitting heaters to the injectors because as we discussed the car changes perfectly when warm, and while we were chatting about haveing changed all the other component's and Tony soaking the injectors in white spirit for a couple of hours, we thought of one plan. It was a long shot as neither of us thought that all eight of the injectors would stick, but it was quicker than stripping the air intake off, and if it showed improvement i could keep doing it. So i went home and got my white spirit out, found an old plastic measuring jug, disconnected the gas supply to the injector rail, (one side only) at the filter and with the engine warm but off, i filled the pipe full of spirit. I then left it for about 5 mins having reconnected it and then started the engine, let it warm up a little and then took the revs up to about 4,500-5,000, switched over to gas and let the engine suck the spirit through as the revs come down and then let it tick over till it was smooth. I repeated this 3 times on each side and then took it for a gentle drive around. I left it till today to try it and it just went straight over as smooth as you like.

nick_haynes · #31 Post by **nick_haynes** » Sun Dec 31, 2006 3:13 pm

Part two. My thoughts are this. 1. I only ever used one supplier, (who shall remain nameless)and even if i was generous and said it took Eight weeks to dergrade to the point where it would not change over, how much rubbish was there in that gas and why don't the filters stop it? (i no longer use that supplier). 2. What made a difference to the injectors while they were out of the car in the boot while i fitted the new engine as when i tried it it changed perfectly? 3. Is there an addative or method that anyone has used to clean their injector rails other than White spirit that was as affective as i am unsure of the effect on the engine long term? I know that its fixed, but i would be interested in anyones thoughts. I will keep an eye on the change over and let you know if it starts to degrade again. Happy New Year, Nick, (thought i'd beat the twelve O'clock rush).

woody · #32 Post by **woody** » Sun Dec 31, 2006 10:57 pm

Hi Nick , happy new year and that,i am glad that you have solved your vaporiser problem, however before the whooping finishes,it is very possible that you may have destroyed your cats by firing all that partially burnt white spirit through them,they will only support approx 4% missfire before damage occurs. Cheers Keith

nick_haynes · #33 Post by **nick_haynes** » Mon Jan 01, 2007 1:15 am

Hi keith, happy new year to you too. What cats? (Allegedly Cheers, Nick.

woody · #34 Post by **woody** » Mon Jan 01, 2007 10:20 pm

Unless your car originated from Australia it should have been fitted with them ]alegedly]. It is not uncommon for them to dissapear for 364 days of the year and then magically re appear!! Cheers Keith

nick_haynes · #35 Post by **nick_haynes** » Tue Jan 02, 2007 6:29 pm

Hi Keith. They would be some o them there lesser spotted Urban Gassus Catus i suspect and your right, i did only have to feed them once a year, although they are being replaced by some permanent Sportus Catus very soon. The changeover this morning was good and on the way home. Do they really not need them in Australia? Cheers Nick.

nick_haynes · #36 Post by **nick_haynes** » Fri Jan 26, 2007 11:18 pm

Hi all. I am just reporting that the gas changeover has degraded again but took till now and it seems that i just need to take of the injectors and mechanically clean them as every time i clean tham out with white spirits they're fine for a time but eventually stop changing over. Any more thoughts would be great. Cheers, Nick.