i got a 1990 chevrolet k1500 5.7L 350 and it aint starting..
new fuel pump,fuel filter,fuel pressure regulator.
injectors tested(still works)
new ECM
no blown fuses.

dash is taking out to expose all wiring..
no melted wires...all looks good...no start..

solutions???      

the late 80's early 90's 350's would sometimes not start after they had been run a while, but then would start the next morning, they sometimes would seem to miss a little or act like they were going to die and then come back. this was a sign of a ingnition control mod. in the dist. they can be tested.  

the invisable problem maybe deeper...   on the small cap gm hei's the have a problem with the magnet on the dist shaft... they crack and cause multiple waveforms that are out of phase from the pickup coil...    this freeks out the module and the ecm so they don't know what to ***

this is the part that goes bad...

ac delco # 10467353 SHAFT, DIST  is the description...

if you pull the rotor.. take a bright narrow beam flashlight and look carefully at the magnet sandwiched in the reluctor...      if you see cracks... you have more than likely found the problem....

do not use a hammer and punch with the shaft unsupported... the shock waves will damage the magnet almost every time...   it is also a good idea to replace the pick up coil at the same time...   if you decide to do it your self and not just put in a good used unit or reman one... sometimes the shafts are hard to get....

if you have a friend with a handheld digital storage scope ... with this hooked up to the pickup coil and set with watch a/c voltage waveforms on the pickup coil..

for those with digial voltmeters...  that have hertz readouts...   test for resistance..   then for a/c volts with the shaft spinning...   then turn to hertz... and with a power drill driving the shaft at a locked speed... look for variations in frequency..


ih... and back to your problem... you really need a scan tool ... this way you can watch the same data the ecm sees...   gives you the heads up on just throwing parts at it blindly...  

I've got a '92 Silverado, and had this happen to me. The distributor's probably fine, the likely culprit for your problem is the throttle position sensor. If the TPS is bad, the truck won't start.

The other possibility is the fuel pump relay, but I'll bet the TPS is bad and needs to be replaced. Good thing is they're only about $30 at your local parts store.  

i should of been a little more clearer on what i said...i still have spark....but the injectors do not pulse when the key is turned to start...

the fuel down the throttle body trick works...starts and runs until the fuel is gone

fuel gets throught the t-body but doesnt go past the injectors....took the injectors to get tested again...still works...  

did you swap the chips over to the new ecm.....


did you pick up a scan tool......  200 cocos  at c s ***

that way you can see the throttle position voltage change..   the rpm signal through the ecm...  injector pulse width... in milliseconds...


so many things it can be... now...

if you cannot see the same data the ecm sees .. you can change parts all day long...

that is called the shotgun mode of auto repair....

start reading here.... its free...  

http://www.autozone.com/shopping/repairGuide.htm?pageId=0900c1528008f0d1

there is at least 2  more hours of reading there...  again its free...

it does cover several years of your model truck... and the newer ones are slightly different that your 90 model... but not that much different

you cannot get data with a code reader...  only a scan tool....