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Hard Warm Start by FieroGT1986
Started on: 12-08-2013 01:16 PM
Replies: 8 (1268 views)
Last post by: FieroGT1986 on 12-13-2013 04:33 PM
FieroGT1986
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Report this Post12-08-2013 01:16 PM Click Here to See the Profile for FieroGT1986Send a Private Message to FieroGT1986Edit/Delete MessageReply w/QuoteDirect Link to This Post
Hello Again...I only drive the car once/twice a week. It starts perfectly when cold or I have not had the chance to drive it for a few days. For some reason when the engine is warm or running around town it takes too long for the engine to fire when warm/hot. It does not do this all the time but I would say a majority of the time. Any thoughts would be appreciated. Thank You
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ltlfrari
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Report this Post12-08-2013 02:14 PM Click Here to See the Profile for ltlfrariClick Here to visit ltlfrari's HomePageSend a Private Message to ltlfrariEdit/Delete MessageReply w/QuoteDirect Link to This Post
Well you only need three things for it to fire, fuel, air and a spark. Getting air is pretty much a given so......
Are you getting a spark when hot. Maybe get an inline spark plug tester and throw it in there when hot to see if you are getting a spark



If no spark then I'd suspect heat soak affecting the coil and/or ignition module.

If you have a spark then it's gotta be fuel. Check you have fuel pressure when hot/not running. turn on ignition (do not start). pump should run for a couple of seconds then turn off,. Take a rag to stop fuel spurting everywhere and depress the schraeder valve in the fuel line, Pass side of engine by intake manifold to see if you get fuel. Be careful it may spurt everywhere and fuel and a hot engine are not a good mix, hence the rag.

No fuel. Check the pump does actually run when you turn on the ignition, you should be able to hear it. If not I'd track that down, maybe bad relay (affected by heat?) or pump itself.

If you have fuel, why is it not getting into the cylinders (injectors?)

Well that's the way I'd go at it.

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phonedawgz
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Report this Post12-08-2013 04:08 PM Click Here to See the Profile for phonedawgzClick Here to visit phonedawgz's HomePageSend a Private Message to phonedawgzEdit/Delete MessageReply w/QuoteDirect Link to This Post
IF

If your fuel pump relay fails - then what happens is the fuel pump only receives power via the oil pressure switch. GM designed the oil pressure switch as a back up to the fuel pump relay. If the relay (or the part of the ECM that sends the signal to the relay) fails then you will have to crank the engine till you build up enough oil pressure before the fuel pump is activated.

How to test to see if this is what is happening - turn the key to on and listen for the fuel pump to run for two seconds. It should. If you can't hear anything then crank the engine till it start and then shut it off right away. Now do you hear the fuel pump? It should run for a few seconds (or more) after you turn the key off. If you do this when the oil is cold it may run on for some time.

So if the fuel pump runs on the oil pressure switch but not the fuel pump relay then try replacing the relay and see if that fixes it.
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fierosound
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Report this Post12-09-2013 12:00 PM Click Here to See the Profile for fierosoundClick Here to visit fierosound's HomePageSend a Private Message to fierosoundEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by FieroGT1986:

It starts perfectly when cold or I have not had the chance to drive it for a few days. For some reason when the engine is warm or running around town it takes too long for the engine to fire when warm/hot.


Check the fuel pump relay first. If that's OK, the problem is elsewhere.

What's the exhaust look like when it starts hot/warm?
You may have leaking injectors flooding the engine.

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2.5
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Report this Post12-09-2013 01:17 PM Click Here to See the Profile for 2.5Send a Private Message to 2.5Edit/Delete MessageReply w/QuoteDirect Link to This Post
Some vehicles exhibit this symptom if they have leaky injector/fuel systems, when you shut it off after driving gas leaks down, creating a flooded condition. It will start like it is flooded.
If you leave it sit til cold the gas will evaporate and it will start like nothing is wrong.

Also for me, if a starter was failing, (needing too much electric currect to function) it was worse when hot.
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FieroGT1986
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Report this Post12-10-2013 05:01 PM Click Here to See the Profile for FieroGT1986Send a Private Message to FieroGT1986Edit/Delete MessageReply w/QuoteDirect Link to This Post
From what I am reading I am leading torwards leaky injectors...When warm it does seem to start like it is flooded. If it sits for a day or two it is fine...Any quick fix?
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Report this Post12-10-2013 05:22 PM Click Here to See the Profile for 2.5Send a Private Message to 2.5Edit/Delete MessageReply w/QuoteDirect Link to This Post
Could see what injector cleaner does.
Beyond that i'm not sure other than replacing them.
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jsmorter
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Report this Post12-10-2013 05:55 PM Click Here to See the Profile for jsmorterSend a Private Message to jsmorterEdit/Delete MessageReply w/QuoteDirect Link to This Post
really dumb question but how is the heat?. If the thermostat is stuck open the computer puts it in open loop and it is harder to start in that mode. I ran into that with a 4 cylinder I bought with no thermostat in it.
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FieroGT1986
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Report this Post12-13-2013 04:33 PM Click Here to See the Profile for FieroGT1986Send a Private Message to FieroGT1986Edit/Delete MessageReply w/QuoteDirect Link to This Post
The heat seemed fine when I had to use torwards the end of the summer season. I do not drive the car in the winter. I will try Injector cleaner this spring. Any recomenadtions? Thank You
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