Won't start after a good run.

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robbie_742003
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Won't start after a good run.

Post by robbie_742003 »

Hello all,

If I ever take my car on a long ish run (1 hour plus) if I try to restart straight away it won't start. Reeks of fuel and needs 20 mins before I can get on my way.
I know these cars run rich anyway but it feels like it's flooded with fuel.
Where do I start looking?

Rob
markstevieandmads
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Re: Won't start after a good run.

Post by markstevieandmads »

Coil
robbie_742003
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Re: Won't start after a good run.

Post by robbie_742003 »

Nope, coil is good.
markstevieandmads
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Re: Won't start after a good run.

Post by markstevieandmads »

how do you know? Have u checked how its earthed as earths through the bracket and body.
robbie_742003
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Location: Midlands

Re: Won't start after a good run.

Post by robbie_742003 »

I've already had the coil bracket off and ground off any paint for a good earth on a previous.

I'm aware of the need for a good coil earth.
jimGTS
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Location: North Kent

Re: Won't start after a good run.

Post by jimGTS »

pretty sure its only the ignitor thats needs to be grounded, not the coil.
yokomomr4bx
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Re: Won't start after a good run.

Post by yokomomr4bx »

Surely this is more indicative of a crank sensor - quite common symptom is failure to start when warm but will start fine when cool/first thing. Certainly would explain the lack of ignition.
robbie_742003
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Joined: Wed Dec 15, 2004 7:50 pm
Location: Midlands

Re: Won't start after a good run.

Post by robbie_742003 »

jimGTS wrote:pretty sure its only the ignitor thats needs to be grounded, not the coil.


Meant the bracket.
robbie_742003
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Joined: Wed Dec 15, 2004 7:50 pm
Location: Midlands

Re: Won't start after a good run.

Post by robbie_742003 »

yokomomr4bx wrote:Surely this is more indicative of a crank sensor - quite common symptom is failure to start when warm but will start fine when cool/first thing. Certainly would explain the lack of ignition.


Here's the thing, I could run about all day doing short hops and get back in with the engine warm every time with no problems.

But if I do a long run of an hour or more, it reeks of fuel when I try to restart and will only let me get on my way after about 20 mins.

Your suggestion is something I'll look into though, thanks
:thumleft:
Dale_V
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Re: Won't start after a good run.

Post by Dale_V »

-the mr2 doesn't have a crank sensor

-the coil pack IS earthed through the bracket it shares with the ignitor

I know you've had the "coil bracket off and ground off any paint for a good earth"

but have you had the coil pack actually off of the bracket? the coil earths through the bracket and the mating surfaces rust really bad
robbie_742003
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Location: Midlands

Re: Won't start after a good run.

Post by robbie_742003 »

Dale_V wrote:

but have you had the coil pack actually off of the bracket? the coil earths through the bracket and the mating surfaces rust really bad


Hi Dale,

Cheers for the response.

I changed the coil and ignitor a few years ago and the car hasn't seen a lot of rain since its been garaged.
Whats confusing me is that it will start fine if its piddling raining, cold etc etc.

Just when its hot after a long run only.

Could cracks in the case (if there are any) be absorbing engine heat and causing problems?

Rob
Dale_V
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Re: Won't start after a good run.

Post by Dale_V »

Yeah any cracks will play havoc

my cars garaged, doesn't even see the rain, but a few years back I had similar issues, in the end I just bought a new coil pack and upon changing it the old one wasn't cracked but the surface between coil and bracket was rusted bad.

cleaned the bracket and just put the new one on anyway, prob solved.
yokomomr4bx
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Re: Won't start after a good run.

Post by yokomomr4bx »

The mr2 doesn't have a crank sensor...? Interested to know what that sensor in the distributor housing is then! Crank/cam sensor, pick a name, same function in this case.
Dale_V
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Re: Won't start after a good run.

Post by Dale_V »

yokomomr4bx wrote:The mr2 doesn't have a crank sensor...? Interested to know what that sensor in the distributor housing is then! Crank/cam sensor, pick a name, same function in this case.


As in an independent/changeable crank sensor. The mr2 doesn't have a crank sensor. Fact.
yokomomr4bx
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Re: Won't start after a good run.

Post by yokomomr4bx »

My apologies if I have mislead the OP by referring to this sensor as a crank sensor, if you were to do a google search for the crank sensor location on our engine you would be well directed :) I don't think its worth debating what is ultimately inconsequential to the running of his engine though! The wires that feed the crank/cam position sensor are well documented to become fragile over time, would be worth a few minutes to check them over.

I assume you've replaced the rotor and distributer cap in the time since you changed the coil and ignitor? I know you say the coil is good, but out of interest what brand of coil did you put on? I only ask because I've used poor quality coils in the past that have barely lasted over a year and yet when off the car for a resistance check appear completely within normal spec - replaced with a new one just to rule it out completely and any starting/running issues disappear.

Here's a link to a recent thread on here relating to ignition issues in which members gave me some great ideas.

http://www.imoc.co.uk/forums/viewtopic. ... c&start=20
robbie_742003
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Joined: Wed Dec 15, 2004 7:50 pm
Location: Midlands

Re: Won't start after a good run.

Post by robbie_742003 »

yokomomr4bx wrote:

I assume you've replaced the rotor and distributer cap in the time since you changed the coil and ignitor? I know you say the coil is good, but out of interest what brand of coil did you put on? I only ask because I've used poor quality coils in the past that have barely lasted over a year and yet when off the car for a resistance check appear completely within normal spec - replaced with a new one just to rule it out completely and any starting/running issues disappear.


Thanks for the response :thumleft:

It was new but I'm not sure where the coil came from tbh, and cap & rotor was replaced a couple of years ago, it has been limited mileage since though.
I guess my first port of call is to replace all these then.

Rob
yokomomr4bx
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Location: Cardiff

Re: Won't start after a good run.

Post by yokomomr4bx »

I would definitely start with the coil, decent NGK branded one. If the engine has seen limited milages then I would just rub any scale off the contacts of the distributor cap and the rotor and go from there.
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