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Hard start after warmed up


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I have an 87 conquest. I am running a Holly EFI standalone computer ,car fires up fine with cold start and will fire up fine if it’s been sitting for at least an hour or more after reaching full operating temperature. But, if I shut it off after it’s fully warmed up and then try to start at five minutes later or 15 minutes later, it won’t start or as hard to start. I know a lot of the community  runs aftermarket computers and may have some thoughts on this. I will tell you that my fuel pressure seems to be holding fine and the fuel systems in great shape. So I think that can be taken off the table , thanks for the help 

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I don't know anything about a holly standalone but, as tux indicated, you should have the ability to update your startup fuel curves based on temperature.    What are your AFRs when it does finally start?   That will give you an indication on whether you are flooding it or not giving it enough fuel.    Does the computer tell you the air/engine temperature?     I have had similar issues on mine, and still do depending on the specific temperature.   It takes a long time to iron these out because you really only get one shot at that moment and at that temperature.    

 

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Wondering if it possibly could be the starter. I only mentioned that, not disregarding what you guys have mentioned, but once it’s hot, this is the original starter and perhaps is drawing a lot more amperage now, when hot

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Hot start issues are often caused by heat soak on the IAT sensor, the ECU won’t add enough fuel until some air movement brings the sensor down.

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On 6/7/2024 at 1:15 AM, 03CL55AMG said:

Wondering if it possibly could be the starter. I only mentioned that, not disregarding what you guys have mentioned, but once it’s hot, this is the original starter and perhaps is drawing a lot more amperage now, when hot

If it's slow to crank or something, maybe your alternator isn't charging the battery,  but I'm going with startup fuel map

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