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Hot start issues

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Hot start issues

Postby maynemike » Fri Dec 08, 2017 5:24 am

Hi All! I have a 91 Bighorn 4jg2, love it but the last few days have been pretty frustrating as it doesn't want to start after warming up. It runs like a top when it's going but it only starts occasionally after a ride and it's getting worse. Cranks well, fuel to filter, but I haven't seen any other posts dealing with this. I would super appreciate some expertise out there, I'm a paramedic and I need my wheels! Cheers
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Re: Hot start issues

Postby stardog » Fri Dec 08, 2017 2:29 pm

I had a similar problem ages ago getting fuel to filter but after a bit the engine wouldn't start turned over ok.
I had to pump the plunger on the filter and it would start then cut out again bad fuel filter plunger getting air in it have you changed the fuel filter lately could have crap in it or you need a new fuel pump filter assembly.
I got a new fuel filter holder no more problems since you could run a clear plastic hose from the fuel filter to the pump and see if there are any air bubbles in it while the engine is running that will tell you if its bad.
Don't leave the clear plastic pipe on it as its only to check if you have air getting in or fuel is draining back to the fuel tank,
Only other thing I could think of is fuel cut off solenoid is playing up.
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Re: Hot start issues

Postby maynemike » Sun Dec 10, 2017 7:11 am

Thanks for the reply Stardog. I will check for air leaks post filter with a clear hose, can air be the culprit for refusing to start warm? I have been dealing with this for a week now and it's pretty predictable, starts cold, refuses when warm, just cranks. I can drive it fine just have to remember not to shut it off! As far as I have read here, the solenoid shuts down the fuel when the key turned off. I checked it warm today and there was no click to be heard or felt with my finger on it. I will try cold to see if I get a different result and that I guess would indicate a faulty solenoid. Then I would have to track one down..not sure what my options are yet for parts here in Canada, (BC).
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Re: Hot start issues

Postby stardog » Sun Dec 10, 2017 12:13 pm

You can get them on freewai.com im pretty sure the fuel solenoid is the same for a 4jb1 and 4jg2 injector pump,
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Re: Hot start issues

Postby maynemike » Wed Dec 13, 2017 7:36 am

No bubbles past the filter with clear tube and I drove it twice for a half hour today and after the second run it won't start again. Solenoid must be working to start it, does anyone know the best way to bleed the air ?
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Re: Hot start issues

Postby stardog » Sun Dec 17, 2017 2:30 pm

I would start following the fuel lines back to the fuel tank maybe have a blockage in the fuel tank or bad fuel if you have a air compressor disconnect the fuel line from the fuel filter and give the fuel hose back to the tank a blow of air make sure you loosen the fuel cap first might help.
When it refuses to start when warmed up how does the starter motor whirl over plenty of power or does it struggle to turn the engine over I had this problem on my truck found the starter motor was stuffed new starter motor fixed this problem.
Just a few things that might help you out if this don't fix the problem I would be taking it to auto sparkie and they might find the problem for you.
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Re: Hot start issues

Postby turnturn » Thu Dec 28, 2017 6:56 am

I dont think that you have eliminated the fuel cut off solenoid side of things.

It could be the solenoid or the power supply to it.

Next time it plays up check the voltage at the solenoid. From memory it has to be above 9 volts.

Consider making up a fused and switched power supply directly from the battery that you can bypass the original system with.

I have previously had a fault in the wiring that supplies the fuel cutoff solenoid and used the above method. Mine was in the fuel cutoff wiring loom attached to the engine. It had been pinched between the engine block and bell housing during a clutch replacement (not by me).
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Re: Hot start issues

Postby maynemike » Wed Jan 10, 2018 1:53 am

Thanks for your replies all! I ended up removing the stop solenoid and it did nothing when I wired it to the battery. Put in a new one and yup, she starts! The intermittent thing was a mystery, I hope this helps someone else, Cheers!
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