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350 TBI no start

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Old 06-11-2012, 03:06 PM
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350 TBI no start

I have this 350 TBI that is getting fuel, and spark and code 12 when i jump the OBD1 port but wont start and won't even sputter, someone replaced the distributor recently but even if the timing was wayyyy of shouldn't it atlest spit/sputter? it really just does notthing but turn over..

Also, noticed this.. if you advance or retard the timing back and forth the injectors will fire... what gives??

its a 92 btw.
Old 06-11-2012, 03:18 PM
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Re: 350 TBI no start

If the plugs are fuel fouled and the timing is way off you may not hear any sign of detonation . You should double check the distributor for being installed correctly number one cylinder at tdc and the firing order in a clock wise manner 1,8,4,3,6,5,7,2 .
Old 06-12-2012, 10:43 AM
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Re: 350 TBI no start

Originally Posted by jay7199
I have this 350 TBI that is getting fuel, and spark and code 12 when i jump the OBD1 port but wont start and won't even sputter, someone replaced the distributor recently but even if the timing was wayyyy of shouldn't it atlest spit/sputter? it really just does notthing but turn over..

Also, noticed this.. if you advance or retard the timing back and forth the injectors will fire... what gives??

its a 92 btw.

If the timing 40 to 50 deg off you will not get fuel ignition - fuel mixture needs to be compressed to get any spit or sputter. Fuel injectors fire regardless of the distributor position - this is OBD-I system which does not have cam sensors to determine which cylinder to fire next - it just fires on the next DRP signal transition.

This is what you need to do:
Get # 1 spark plug out (actually removing all 8 plugs makes turning engine easier). Have a helper turn engine with breaker bar (clockwise when facing engine) while you have a finger over #1 cylinder plug hole. Once you feel air trying to escape - you are on compression stroke - observe balancer timing marks while turning engine clockwise until you see timing marks indicate TDC. Remove dizzy cap and observe rotor position. You may want to pull dizzy and reposition distributor shaft so that rotor points toward factory location of the #1 cylinder shown below (makes for cleaner sparkplug wire routing):

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You'll need a long blade screwdriver (I prefer BFS by Craftsman) to rotate oil pump shaft ever so slightly so that dizzy gear engages into it correctly when dropped back in place. It is a bit of PITA, but once done needs no further manhandling. Re-install everything. Install distributor clamp - but tighten enough for dizzy to turn.

Once engine fires allow it to warm up. You'll need timing light to set base timing with EST connector open - LO3 base timing is 0 to 4 deg range (check you emission label). Secure distributor clamp. Shut off engine, disconnect battery to clear code 42 and reconnect EST connector. Re-start engine - ECM is now controlling timing and it should be bouncing between 16 and 20 deg BTDC.

//RF
Old 06-12-2012, 10:51 AM
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Re: 350 TBI no start

If the injectors are not pulsing unless you advance or retard the timing you have a issue with the high or low signal getting to the ecm. This would be more likely a faulty connection at the icm or bad icm.
Old 06-14-2012, 10:10 PM
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Re: 350 TBI no start

I redid the timing and replaced the spark plugs, still no start.. iv set distributors plenty of times before so im stumped on what the deal is.

when its cranking you can see the injectors firing, iv been shocked by a plug wire at lest once when it was cranking...

Maybe it blew a headgasket? no oil/water mixture though.
Old 06-14-2012, 10:11 PM
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Re: 350 TBI no start

VATS? do these cars have VATS? someone ****ed with the ignition on this before.. you can turn it over without a key.
Old 06-15-2012, 05:02 PM
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Re: 350 TBI no start

Originally Posted by jay7199
VATS? do these cars have VATS? someone ****ed with the ignition on this before.. you can turn it over without a key.
If it is getting spark and fuel during cranking it should start unless there is no compression or if timing way off. This is assuming that spark energy is strong enough to jump the gap.

If VATS module detects incorrect key resistance it will not send fuel enable signal to ECM - hence injectors will never pulse. VATS can be bypassed by installing correct resistor for security module to detect.

If spark plug wires are routed incorrectly - you will never get a 'burp'.

As a sanity check I would check engine compression.

//RF
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