SOS TBI injectors not firing

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Grand_Wag_85
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SOS TBI injectors not firing

Post by Grand_Wag_85 »

I've got an '82 J10 with a 258 and homebrew TBI. The Jeep has been parked in storage for the last 2 years and was started and run quite a few times in 2016 and only once in 2017. Went to go pull the truck out of the garage and threw in a new battery. When I turn the key I can hear the fuel pump doing its thing and there is fuel in the lines and fresh fuel in the tank but when I try to start the truck all it does is crank. I manually poured fuel down the throttle body and the Jeep fires right up and runs but does not stay running unless you pour more fuel down the TB.

Not getting any trouble codes and everything I can find online says that this usually only happens if there is no spark, but that's not the case.

I flew cross country thinking I could hop in it and drive off but the Jeep has other ideas...In the past it's always been dead reliable, LOL! It did the same thing last year but after a splash of gas down the TB it fired right up and stayed running.

Anyone have any ideas?

Thanks.
82 J10
77 J10 Golden Eagle 401
88 GW

You know it's bad when your car is on the EPA's 10 most wanted list!
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babywag
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Re: SOS TBI injectors not firing

Post by babywag »

If injectors are not firing & you have spark, the ecm is probably not seeing the tach signal?
Since no idea how it's setup...
check obvious, fuses, wiring especially grounds, and they tach signal to ecm wire.
-Tony
'88 GW (aka Babywag)
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Grand_Wag_85
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Re: SOS TBI injectors not firing

Post by Grand_Wag_85 »

babywag wrote:If injectors are not firing & you have spark, the ecm is probably not seeing the tach signal?
Since no idea how it's setup...
check obvious, fuses, wiring especially grounds, and they tach signal to ecm wire.
I'll take a look
82 J10
77 J10 Golden Eagle 401
88 GW

You know it's bad when your car is on the EPA's 10 most wanted list!
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Grand_Wag_85
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Re: SOS TBI injectors not firing

Post by Grand_Wag_85 »

As a shot in the dark I replaced the ignition module and no luck.

Going to dig into the wiring a bit more
82 J10
77 J10 Golden Eagle 401
88 GW

You know it's bad when your car is on the EPA's 10 most wanted list!

RamJetFSJ
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Re: SOS TBI injectors not firing

Post by RamJetFSJ »

Injectors could possibly be clogged. Gas these days does some nasty stuff when it gets old. I left my TPI motor sit for too long and all but 1 injector was clogged up. Had to send them out to be sonic cleaned.
80 Wag in 73 attire, Ram Jet 350 power
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Grand_Wag_85
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Re: SOS TBI injectors not firing

Post by Grand_Wag_85 »

Got her did! Injectors were not receiving power from the ignition switch.

I completely forgot that I had a battery cook off right before I parked it and some of my homebrew TBI wiring was effected.

One of my first thoughts was that the injectors were clogged. I removed the wires and manually fired them with test wires and it worked.
82 J10
77 J10 Golden Eagle 401
88 GW

You know it's bad when your car is on the EPA's 10 most wanted list!

bigun
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Re: SOS TBI injectors not firing

Post by bigun »

You know if it was a carburetor....
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Grand_Wag_85
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Re: SOS TBI injectors not firing

Post by Grand_Wag_85 »

bigun wrote:You know if it was a carburetor....
I'll finish that sentence.....It still wouldn't start :shock: :-bd

Actually I had REALLY good luck with my Weber but in 2015 the carb was feeling really tired and I thought I'd get all fancy and fuel inject it for Ouray 2016, and I ended up going in the wrangler anyway. Towing the trailer up the passes on I70 the 258 in the J10 dogged pretty good.
82 J10
77 J10 Golden Eagle 401
88 GW

You know it's bad when your car is on the EPA's 10 most wanted list!
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