non start when hot
08-19-2016, 06:46 PM
#1
Advanced
Thread Starter
non start when hot
hello all..ive just purchased a 86 c4 glasstop....when I picked it up it started fine,engine was cold..drove about 10 minutes and stopped to refuel,after it would crank fine but not start..the guy did tell me this had happened to him once and it started ok with a sniff of easy start spray..i purchased a can and yes it started ok with a small sniff...the car run fine for the drive home about 330 miles..i didn't turn it off until I got home and again when I tried to restart it it just cranked over but didn't fire...im suspecting a fuel metering fault i.e maf sensor or possibly a fuel priming fault..anyone had this fault.will try it again in the morning from cold.i bet it starts ok.any help would be appreciated.
also when I got home the word security flashed on the dash,then the alarm sounded..im guessing you have to exit the vehicle within 20-30 seconds of removing the key?...if someone could confirm if this is normal, would be great
also when I got home the word security flashed on the dash,then the alarm sounded..im guessing you have to exit the vehicle within 20-30 seconds of removing the key?...if someone could confirm if this is normal, would be great
Last edited by Sid.123; 08-19-2016 at 06:47 PM.
08-19-2016, 08:29 PM
#2
I would look at the coil and ignition module. And the fuel pressure.
Last edited by antfarmer2; 08-19-2016 at 08:30 PM.
08-20-2016, 02:28 AM
#3
Race Director
The SECURITY light flashes if the door is open and the security system is NOT armed. It will stay on steady if the security system IS armed with the door open. The light will go out if the door is closed or the ignition is turned on.
The door must be closed within 45 seconds of arming the system (by locking the door) or the alarm will sound.
Does your fuel pump run for 2 seconds when the ignition is first turned on? If not then you might have a fuel pump relay problem.
The door must be closed within 45 seconds of arming the system (by locking the door) or the alarm will sound.
Does your fuel pump run for 2 seconds when the ignition is first turned on? If not then you might have a fuel pump relay problem.
08-20-2016, 09:32 AM
#4
Advanced
Thread Starter
Started it this morning,started fine from cold...ran it for 10 minutes to warm it up.turned it off and again would only crank over. Will check the fuel pump relay tomorrow when I've got more time
08-20-2016, 11:13 AM
#5
08-20-2016, 11:17 AM
#6
08-20-2016, 01:06 PM
#7
08-20-2016, 05:36 PM
#8
Advanced
Thread Starter
I'm just a bit baffled...the relay must work to start it from cold. Will check it out later and post my findings...
Removed the pump relay and checked for operation,working ok. Cleaned contacts and replaced. Fuel pump primes n runs ok..
Removed dizzy cap, rotor and module and cleaned everything up put it all back but still doesn't start when warm.
Haven't got anything to measure fuel pressure but will order dizzy cap,arm, module n leads and see if that improves things
Removed the pump relay and checked for operation,working ok. Cleaned contacts and replaced. Fuel pump primes n runs ok..
Removed dizzy cap, rotor and module and cleaned everything up put it all back but still doesn't start when warm.
Haven't got anything to measure fuel pressure but will order dizzy cap,arm, module n leads and see if that improves things
Last edited by Sid.123; 08-21-2016 at 05:14 PM.
08-21-2016, 06:26 PM
#10
Just get a "loaner" at the auto parts store to do your check and then do a buy later. If you mention wanting to likely buy AZ will sometimes order in a NEW for you to use as a loaner. I'd maybe avoid most eBay buys - way to much counterfeit stuff on the market. I'd pay maybe more locally then if I had issues I could likely be accommodated.
08-21-2016, 06:32 PM
#11
08-21-2016, 06:36 PM
#12
I'm just a bit baffled...the relay must work to start it from cold. Will check it out later and post my findings...
Removed the pump relay and checked for operation,working ok. Cleaned contacts and replaced. Fuel pump primes n runs ok..
Removed dizzy cap, rotor and module and cleaned everything up put it all back but still doesn't start when warm.
Haven't got anything to measure fuel pressure but will order dizzy cap,arm, module n leads and see if that improves things
Removed the pump relay and checked for operation,working ok. Cleaned contacts and replaced. Fuel pump primes n runs ok..
Removed dizzy cap, rotor and module and cleaned everything up put it all back but still doesn't start when warm.
Haven't got anything to measure fuel pressure but will order dizzy cap,arm, module n leads and see if that improves things
08-22-2016, 07:04 PM
#15
08-23-2016, 03:03 PM
#16
Le Mans Master
hello all..ive just purchased a 86 c4 glasstop....when I picked it up it started fine,engine was cold..drove about 10 minutes and stopped to refuel,after it would crank fine but not start..the guy did tell me this had happened to him once and it started ok with a sniff of easy start spray..i purchased a can and yes it started ok with a small sniff...the car run fine for the drive home about 330 miles..i didn't turn it off until I got home and again when I tried to restart it it just cranked over but didn't fire...im suspecting a fuel metering fault i.e maf sensor or possibly a fuel priming fault..anyone had this fault.will try it again in the morning from cold.i bet it starts ok.any help would be appreciated.
also when I got home the word security flashed on the dash,then the alarm sounded..im guessing you have to exit the vehicle within 20-30 seconds of removing the key?...if someone could confirm if this is normal, would be great
also when I got home the word security flashed on the dash,then the alarm sounded..im guessing you have to exit the vehicle within 20-30 seconds of removing the key?...if someone could confirm if this is normal, would be great
08-23-2016, 04:30 PM
#17
Advanced
Thread Starter
Check your fuel pressure both cold and after it's hot. Also check to see if it holds pressure before you crank it, I didn't see it answered anywhere but if you give it partial throttle when it's hot does it start up? Early C4's have a cold start valve and at this point a lot of them have started to leak and that can cause hard starting issues when warm.
I'm sure we're in the right area though. The more I check things I keep come img back to fuel pressure.
08-23-2016, 04:55 PM
#18
Le Mans Master
That is a possibility however at this time I haven't anything to test the pressure. What I can say is when it doesn't start I've tried partial and full throttle thinking the same thing.
I'm sure we're in the right area though. The more I check things I keep come img back to fuel pressure.
I'm sure we're in the right area though. The more I check things I keep come img back to fuel pressure.
Also I saw discussion on the fuel pump relay, if the relay is bad the fuel pump still energizes when the oil pressure hits 3 psi (or somewhere thereabout) so a bad fuel pump relay would be a bit of a red herring in this instance.