93 K1500 350TBI Wont Start

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93 K1500 350TBI Wont Start

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Chevrolet Forums >> Chevy Trucks, Vans & SUV's >> Suburban >> 93 K1500 350TBI Wont Start

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93 K1500 350TBI Wont Start - 5/7/2008 7:32:09 PM

onsite

Posts: 1
Joined: 5/7/2008
Status: offline

I have a 93 Burb w/5.7 and TBI that is giving me fits. Fuel Squirts out the injectors while you crank it but there is no spark. Recently I put in a whole new distributor which came complete with all new parts (Cap, Rotor, ICM and Pickup) because of this same intermittant start issue. After the new dist. it ran fine for about 40 miles, died and now won't start again - NO SPARK. I pulled the ICM from the new distributor and replaced it with a another new one - but still won't start.

Heres what I've checked and done.

IN TANK PUMP RUNS AND FUEL SQUIRTS FROM INJECTORS DURING START SEQUENCE
HAD A NEW FUEL PUMP RELAY SO THREW IT IN JUST FOR GIGGLES - NO HELP
OIL PRESSURE COMES UP ON GAUGE WHILE CRANKING SO I ASSUME THE O.P. SENDING UNIT IS GOOD.
NEW WIRES AND PLUGS
NEW ICM IN AN OTHERWISE ALREADY NEW DISTRIBUTOR - YES IT GOES ROUND AND ROUND
NEW COIL - THERE IS POWER INTO THE COIL BUT NO SPARK FROM COIL TO CAP - NO SPARK ON ANY PLUG WIRE
CLEANED, CHECKED AND TIGHTENED ALL GROUNDS I COULD FIND
BATTERY GOOD
ECM GETS POWER
ECM KICKS OUT #54 CODE - LOW FUEL PUMP VOLTAGE - BUT ITS NOT GOING TO START ANYWAY WITHOUT SPARK
CLEANED AND CHECKED ALL ENGINE to COMPUTER CONNECTIONS I COULD FIND.
ALL FUSES AND FUSIBLE LINKS GOOD

Any Ideas?

Does anyone have a pinout diagram for the ECM? This ECM has a 1 red and 1 blue connector both same size.

Does the ECM control the spark or just the timing and does the ICM in the distributor tell the ECM that the engine is turning over so go ahead and give spark?

What is the sequence of events?

I first thought that the ECM would not send fuel or spark to the engine if it could not tell it was turning over but obviously it is sending fuel but no spark so the ECM does knows the motor is turning over.

Maybe the pickup in the new distributor is bad?
ECM is bad?

Post #: 1

RE: 93 K1500 350TBI Wont Start - 5/8/2008 9:31:55 AM

ZX1100F1

Posts: 2408
Joined: 8/1/2006
Status: offline

The ignition system is controlled by the PCM.
I would check the Crankshaft Possition Sensor (CKP), if this sensor signal (pulses) is lost the engine will not run.

< Message edited by ZX1100F1 -- 5/8/2008 9:34:15 AM >

_____________________________

Dave

(in reply to onsite)

Post #: 2