Car starts fine when cold, but not when warm

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Car starts fine when cold, but not when warm - 11/14/2007 5:11:58 PM    Planefreak Posts: 93 Joined: 7/23/2007 From: Oregon Status: offline Ok so when I start my car in the morning it cranks over a few times and starts right up.  That's fine works normally.  Later, when the engine is still warm usually after the car has been sitting for a while my car won't start right away.  It usually takes about 5 seconds then it kind of sputters to life.  After that the rpm will rise slowly and after about 3-4 seconds the starts running normally.  I am thinking it has something to do with the fuel return system.  What do you guys think? _____________________________ My Car: 1986 Honda Accord LXI 2.0 ltr automatic. Post #: 1

RE: Car starts fine when cold, but not when warm - 11/14/2007 5:26:32 PM    TexasHonda   Posts: 1509 Joined: 2/18/2007 Status: offline Try holding the throttle wide open for your hot start. If that dramatically improves starting, your engine is flooding. Most likely reason is a leaking injector allowing fuel to dribble into the hot manifold while engine is warm. When you try to start your engine is flooded. Overnight the fuel will evaporate and you won't have any problem starting. You can confirm a leaking injector by having fuel pressure measured. You will see a steady leakdown from spec pressure to zero, probably in 1-2 minutes. good luck _____________________________ See you down the ROW 1994 Accord EX (in reply to Planefreak) Post #: 2

RE: Car starts fine when cold, but not when warm - 11/14/2007 6:46:15 PM    2POINTautO   Posts: 194 Joined: 9/29/2007 Status: offline Honda does not use the Engine Coolant Temp sensor once the engine is fully warmed up and the computer is in Closed Loop Operation.  The sensor could completely fail, full hot or full cold, and the computer would not care, UNTIL the next key cycle, then if the ECT sensor tells the computer that it is cold when the engine is actually warm, it will tell the computer to deliver more fuel than needed and slightly flood the engine in a scenario like yours.  I recommend you change the ECT sensor as a matter of preventive maintenance as they are common wear and tear items, inexpensive and good insurance for some years to come. This along with the fuel leak down test as mentioned would be great.  Years ago I used to instruct folks to go to Radio Shack and pick up a 330 ohm resistor (I think that was the size) for a no start after a hot soak, 5 ~ 45 minutes, disconnect the ECT connector, insert resistor into car harness connector and start car, if car started, replace ECT, very common problem.  The resistor simulated a warm ECT resistance. _____________________________ Give all the dirty details Year, Make & Model help too Here to help if I can (in reply to TexasHonda) Post #: 3

RE: Car starts fine when cold, but not when warm - 11/15/2007 8:15:54 PM    Planefreak Posts: 93 Joined: 7/23/2007 From: Oregon Status: offline Well, I think you're right.  Giving it gas while starting helped quite a lot.  How do I determine which injector(s) is leaking? _____________________________ My Car: 1986 Honda Accord LXI 2.0 ltr automatic. (in reply to 2POINTautO) Post #: 4

RE: Car starts fine when cold, but not when warm - 11/16/2007 2:48:22 AM    2POINTautO   Posts: 194 Joined: 9/29/2007 Status: offline Without a 5 gas analyser, I think you may have to pull the fuel rail and injectors, apply power to the fuel pump and see which injector is leaking, new o rings for re-installation.  At this point I would recommend all injectors get sent out for professional cleaning and they will determine if that one is still good after cleaning. _____________________________ Give all the dirty details Year, Make & Model help too Here to help if I can (in reply to Planefreak) Post #: 5

RE: Car starts fine when cold, but not when warm - 11/16/2007 5:44:00 AM    falkore24 Posts: 5932 Joined: 8/16/2007 From: Wayne, NJ Status: offline These guys seem to have a pretty good service for injector cleaning .... I had thought about using them, but haven't yet. http://www.witchhunter.com/injectorvideo1.php4 _____________________________ 2006 Scion TC (ZPI-18G pending) 2000 V6-AT (RIP 3G) Temp Search thanks to Finch13 (in reply to 2POINTautO) Post #: 6

RE: Car starts fine when cold, but not when warm - 11/16/2007 2:33:06 PM    TexasHonda   Posts: 1509 Joined: 2/18/2007 Status: offline I don't know of any way to easily isolate the leaking injector. It may be easier to simply replace or rebuild all of them at same time. good luck _____________________________ See you down the ROW 1994 Accord EX (in reply to falkore24) Post #: 7

RE: Car starts fine when cold, but not when warm - 11/16/2007 5:07:00 PM    Planefreak Posts: 93 Joined: 7/23/2007 From: Oregon Status: offline I think that I'll have to rebuild/replace all of them to be sure.  I would use 2POINTautO advice, but this really isn't possible.  The injectors in my car sit in the intake loosely.  Then you place the fuel rail over them and bolt it down.  I would need something to hold each of the injectors in place otherwise I'd have fuel everywhere. I will look into rebuilding them. _____________________________ My Car: 1986 Honda Accord LXI 2.0 ltr automatic. (in reply to TexasHonda) Post #: 8

RE: Car starts fine when cold, but not when warm - 11/17/2007 6:50:48 AM    TexasHonda   Posts: 1509 Joined: 2/18/2007 Status: offline Agree, if you start the fuel pump w/ injectors attached to the rail, the injectors will be ejected from the rail and fuel will go everywhere. good luck _____________________________ See you down the ROW 1994 Accord EX (in reply to Planefreak) Post #: 9

RE: Car starts fine when cold, but not when warm - 11/18/2007 4:12:48 PM    Planefreak Posts: 93 Joined: 7/23/2007 From: Oregon Status: offline Don't know if this is helpful, but I checked the injectors resistance and they all were about 2.6 ohms +/- .1.  I also did Honda's check where you rev up the engine to 3000 and let off and listen to the injectors.  They all seem to be working properly while the engine is running. _____________________________ My Car: 1986 Honda Accord LXI 2.0 ltr automatic. (in reply to TexasHonda) Post #: 10

RE: Car starts fine when cold, but not when warm - 11/18/2007 6:37:49 PM    deserthonda Posts: 3575 Joined: 12/3/2005 Status: offline unplug the TW sensor and see if that helps,, it will kick a code ( 6 ) but you can clear it afterward .. _____________________________ No Year No Model in Your signature No Help from me Take a look in the DIY section before asking for help Always Diagnose First,,, Before Replacing Parts (in reply to Planefreak) Post #: 11

RE: Car starts fine when cold, but not when warm - 11/19/2007 11:58:12 PM    Planefreak Posts: 93 Joined: 7/23/2007 From: Oregon Status: offline What the heck is the sensor beside the tw sensor?  I tested both of the sensors on the thermostat housing.  The tw sensor showed a little high on ohms, but it wasn't a Honda approved test either.  The sensor next to it on the other hand never showed anything but an open circuit.  I tried it on the lowest setting, highest setting and everything in between with no change.  I even warmed the engine and retested with absolutely no change.  I can't find any mention of it in the shop manual or chilton book. _____________________________ My Car: 1986 Honda Accord LXI 2.0 ltr automatic. (in reply to deserthonda) Post #: 12

RE: Car starts fine when cold, but not when warm - 11/20/2007 12:11:32 AM    PAhonda   Posts: 1348 Joined: 9/22/2006 Status: offline I'm not very familiar with an 86, but that could be the cooling fan sensor.  It remains open and only closes past a certain temperature.  Once closed the fans turn on to help cool the engine.  Check out the cooling fan troubleshooting part of the shop manual.  If that is the cooling fan sensor, you could jump the plug and see if the cooling fans come on.  I would NOT do this if you are not absolutely certain that this is the cooling fan sensor. _____________________________ 1995 Accord EX MT (in reply to Planefreak) Post #: 13

RE: Car starts fine when cold, but not when warm - 11/20/2007 8:19:17 AM    Planefreak Posts: 93 Joined: 7/23/2007 From: Oregon Status: offline Good point.  I know the secondary fan sensor is mounted on the bottom of the radiator but I don't know where the other is. _____________________________ My Car: 1986 Honda Accord LXI 2.0 ltr automatic. (in reply to PAhonda) Post #: 14

RE: Car starts fine when cold, but not when warm - 11/20/2007 9:16:12 AM    2POINTautO   Posts: 194 Joined: 9/29/2007 Status: offline Can you backprobe the sensor connector or is there another connector attached to this wiring (pobably not) further away from the sensor, only one wire should be 12 volts, when the fan kicks on then both should be powered.  IF this is the coolant sensor 'A'.  If the one in the radiator is 'A' then this one may not come on at all if it is 'B', its a higher temp.  Sorry I did not look it up, its way past bed time and I have done a couple hundred forum posts tonight. I feel confident that shorting it will be ok, it should be a thermoswitch.  It does have two wires, correct. Can you post pics? _____________________________ Give all the dirty details Year, Make & Model help too Here to help if I can (in reply to Planefreak) Post #: 15

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