73-87chevytrucks.com

73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: Blazin on January 16, 2015, 05:44:32 pm

Title: Starting issue, TBI motor
Post by: Blazin on January 16, 2015, 05:44:32 pm

1987 V20, 350 TBI.
Hard starting, long crank time.
Can get it running, but after a very low idle for a second or three it stalls. Sometimes it won't even do the low idle thing, just stalls.
Once it fires if you catch it with the fuel pedal it will run smooth at 1,200 / 1,500 RPMs, no skips at all. It will run like that for a minute or less, then its like someone shut the key off, just quits. Repeat & thats all it will do.
Has spark when cranking before run. Has 60 / 65 fuel PSI on crank. Going to set it up in line tomorrow, see if pressure drops at stall.
Any ideas?  Ignition module maybe? 
I have had them die before, but always been once they quit, they quit.

Title: Re: Starting issue, TBI motor
Post by: Irish_Alley on January 16, 2015, 07:17:17 pm

blaz im just now getting into these tbi systems. but i want to say icm also but this is a complete guess, vile and bd seam to know a lot about these

Title: Re: Starting issue, TBI motor
Post by: Irish_Alley on January 16, 2015, 07:27:04 pm

i did post this for your cts readings and other tbi sensors


Troubleshooting sensors and how to test (http://forum.73-87chevytrucks.com/smforum/index.php?topic=29996.0)

Title: Re: Starting issue, TBI motor
Post by: Irish_Alley on January 16, 2015, 07:29:48 pm

also about the cel
Obd1 code retrieval and decoding (http://forum.73-87chevytrucks.com/smforum/index.php?topic=29949.0)

Title: Re: Starting issue, TBI motor
Post by: Blazin on January 16, 2015, 07:43:57 pm

My scan tool will do OBD I
I am leaning toward ignition module. Gona pull some codes tomorrow, & do an inline fuel PSI check while it running.

Title: Re: Starting issue, TBI motor
Post by: SLUG on January 17, 2015, 05:10:57 pm

Also, check the spray pattern on the injectors. My 87 has a similar problem. I narrowed it down to bad enjectors flooding the engine.

Title: Re: Starting issue, TBI motor
Post by: Blazin on January 18, 2015, 09:46:39 am

So I put 8 new plugs in yesterday. Started right up, still ran a little rough, with a ow idle, but stayed running, didn't die in less than a minute. Started putting new cap, rotor, & wires on but, had to quit for the night as I had plans. Gona get back at it today.

Title: Re: Starting issue, TBI motor
Post by: Irish_Alley on January 18, 2015, 03:37:46 pm

thought the psi on a tbi was supposed to only be 18 or something low like that?

Title: Re: Starting issue, TBI motor
Post by: pholliday1 on January 18, 2015, 05:50:02 pm

Yeah Irish I caught that too. Your on the right track. 60/65 sounds way high

Title: Re: Starting issue, TBI motor
Post by: Blazin on January 18, 2015, 09:09:04 pm

Did an inline PSI today. its 16.
Popped 8 new plugs in it today. Fired right up, ran perfect.
Did cap, rotor & Wires too while I was in there.