Fish13 Posted October 27, 2009 Share Posted October 27, 2009 Hi guys, Just finished the head gaskets on my 1988 3.5 EFi. Have had the timing checked and all is well there. Put it all back together, ran it and it was fine, put it in the garage overnight and went to start the next morning and it started (eventually) on about 2-3 cylinders and took a while before it coughed into life on all 8. Once running it's great, but left it for another few hours and went to start it again and same thing? Can someone shed any light on what's happened? It was starting fine etc before - it was only leaking water! Cheers in advance, Fish. Quote Link to comment Share on other sites More sharing options...
steve_d Posted October 27, 2009 Share Posted October 27, 2009 A trip around all the connectors is called for. Cold start injector. Extra air valve...good one that as almost impossible to get at. thermotime sensor...you did fit a brand new one when it was all stripped down didn't you? Water temp sensor alongside thermotime. Have you swapped the connectors on the above? ie plugged them in the wrong way round. Steve Quote Link to comment Share on other sites More sharing options...
paintman Posted October 27, 2009 Share Posted October 27, 2009 Soon as it does it remove & check the plugs. Are they wet or dry? Is the wet fuel or water? Dry & put back in. Start & run vehicle until as you say it goes onto all 8. Let it run for a while - to normal operating temp & thermostat opens. Switch off. CAREFULLY slacken rad/expansion tank cap to avoid getting scalded - use a large cloth over the cap that completely covers it to stop any ejected water flying into the air - & allow cooling system to depressurise. Leave vehicle for several hours then refit cap & see if it starts normally on all cylinders. If it does it may be you have an internal leak & the next thing is to have the cooling system pressure tested. When you did the gaskets did you check all mating surfaces were flat, that there was no warpage in the heads? What make head gaskets did you use & which type - normal tin or composite? Did you replace & tighten all head bolts or leave out the outer rows - the outer rows are the 4 short bolts on each side? (Note that current thinking is to leave them out or just nip up the outer rows as they cause the heads to tip. They were eliminated altogether on later V8 engines which have no holes for them and use the 10 hole head gaskets.) Were the head bolts replaced in their correct holes? Did you put a small amount of sealant round the water passages that the inlet manifold gasket contacts? That the vehicle started & ran as normal straight after the rebuild would suggest that everything else is OK. Unfortunately I have met a similar problem on a 3 litre Ford Essex V6 in a Scimitar when non-genuine head gaskets were used - failed after less than 300 miles with identical symptoms to yours. Quote Link to comment Share on other sites More sharing options...
Fish13 Posted October 30, 2009 Author Share Posted October 30, 2009 Hi gents, Many thanks for the replies - I tested the coolant temp sensor, plugs were ok, went round and double checked injectors and sensors were tight and located correctly. Tried your test Paintman, no difference to start-up. However, this morning, I took out the cold start injector from the plenum (took out assembly with injector still attached to harness) and when engine had been left overnight gave it a crank and no fuel whatsoever came out - could this be the culprit? Seems to fit the problem, but does the cold start injector really influence the start-up so much that engine would barely cough on 2-3 cylinders before evetually cranking up to speed on all 8? Hope this is it - if it is, I'm wondering why it worked fine before I took heads off and now doesn't? Cheers, Fish. Quote Link to comment Share on other sites More sharing options...
Bull Bar Cowboy Posted October 30, 2009 Share Posted October 30, 2009 For the 9th injector to work it has to get really cold ……… zero or below……. This is controlled by the thermotime switch (brown top) which is located beside the coolant sensor (blue top). Generally if the coolant sensor is faulty then the engine runs in a permanently rich state………. You seem to have the opposite in that the start-up and after run enrichment is not working correctly. My immediate thoughts are that you need to set up the throttle linkage and TPS position …….. known as the base idle. Another area to look at is the EAV (Extra Air Valve) ……. are the hoses correct and secure ? ………. Is the valve working correctly ? Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted October 30, 2009 Share Posted October 30, 2009 If it's lean then it could also be an air leak anywhere after the airflow meter. Quote Link to comment Share on other sites More sharing options...
paintman Posted October 31, 2009 Share Posted October 31, 2009 Cold start injector on mine's been disconnected since I got the car (in 1994). Never been any issues starting. Quote Link to comment Share on other sites More sharing options...
SteveRK Posted October 31, 2009 Share Posted October 31, 2009 It doesn't sound ignition related so maybe the plugs are getting condensated due to water ingress as the engine cools down (worst case scenario!) or possibly the fuel pressure is taking a while to get up to pressure? Quote Link to comment Share on other sites More sharing options...
paintman Posted November 1, 2009 Share Posted November 1, 2009 It was the water leak thing I was worried about. I would still be inclined to have the system pressure tested to confirm all is OK. Never did get the answer to 'are the plugs wet or dry'. Quote Link to comment Share on other sites More sharing options...
Fish13 Posted November 6, 2009 Author Share Posted November 6, 2009 Hi guys, sorry have been offshore for a while. I tried Paintman's test. Plugs were dry, BUT the no. 1 cylinder spark plug was still brand new with no soot at all. So, took the plug out and connected it to the lead and cranked to see if it fired and it did, so nothing was wrong with the plug. I also swapped 1 with 7 and no change. I replaced the plug and pulled the lead off while engine was running and it didn't change note at all, whereas other ones did. So, my guess is fuel injector, or wiring to the fuel injector for no.1 cylinder? How can I test this? I can put injector cleaner in the tank and run that through, but because it ran fine before and now doesn't seem to be working, would it point to the wiring instead? What am I looking for there, is there a resistance reading or similar that I should look for? Narrowed it down I hope - still need help though, so please keep suggestions coming! Cheers, Fish. Quote Link to comment Share on other sites More sharing options...
tel Posted November 7, 2009 Share Posted November 7, 2009 my car has just started doing this aswell but mine also runs on lpg and with megajolt and no differance no matter what fuel i use but like yours after a while will run asif nothing was wrong with it very confused! Quote Link to comment Share on other sites More sharing options...
paintman Posted November 8, 2009 Share Posted November 8, 2009 The injectors are not cylinder specific on the 3.5. They open as alternate banks of four & spray fuel into the inlet manifold rather than the cylinder. But would still be worth checking them although as the problem clears after a while I nsuspect the fault is not with the injectors. Could there be a fuel pressure issue? Does the system hold pressure as given in the manual checklist? Could there be a valve opening problem? Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted November 8, 2009 Share Posted November 8, 2009 I can't remember the resistance values for flapper injectors, easiest is to pull the plugs and measure them all. A bit like a compression test, if one or two are a lot different to the rest then you know there's a problem. Another test when it's running is to see if you can feel each injector ticking as it fires, or put a screwdriver/bar to your ear and listen. Not always easy but can work. Quote Link to comment Share on other sites More sharing options...
paintman Posted November 8, 2009 Share Posted November 8, 2009 From manual: 1. Use an ohmmeter to measure the resistance value of each injector winding, which should be 2.4 ohm at 20degC (68degF) 2. Check for short circuit to earth on the winding, by connecting the ohmeter probes between each injector terminal and injector body; meter should read infinity. Renew the injector if the winding is open circuit or short circuit. Quote Link to comment Share on other sites More sharing options...
tel Posted November 9, 2009 Share Posted November 9, 2009 i dont think its an injector problem as mine is doing exactly the same thing and is running on gas Quote Link to comment Share on other sites More sharing options...
paintman Posted November 9, 2009 Share Posted November 9, 2009 Genuine parts dizzy caps fitted? Genuine parts rotor arms fitted? If the answer to either or both of the above is 'No' then don't bother doing anything else until you've replaced them with GP ones. I will only buy them from the dealers as there are some rubbish copies out there. To date, the only issues I've had on LPG have been cured by replacing the spark plugs & a rich on petrol start up issue was solved by replacing the temperature sender (the one that feeds the ECU & is the one behind the easy pone on the top front of the manifold. Part number on mine is ETC8496 & genuine part was about £12) Quote Link to comment Share on other sites More sharing options...
Fish13 Posted November 10, 2009 Author Share Posted November 10, 2009 Thanks Paintman, do you mean the thermotime switch or the coolant temperature sensor? Quote Link to comment Share on other sites More sharing options...
paintman Posted November 10, 2009 Share Posted November 10, 2009 Its the coolant temp sensor. Looks like this http://www.lrseries.com/shop/product/listing/6143/3584/21/ETC8496-TEMPERATURE-SENSOR-COOLANT.html The thermotime switch is the one in front of it that makes it difficult to get at. Thermotime on mine does nothing as the cold start injector is disconnected. Might also have a look here for checklist suggestion http://www.carelect.demon.co.uk/rrind.html Quote Link to comment Share on other sites More sharing options...
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