cruisin'73

iTrader: (8)

Hey guys I need your help! I just finished converting my 5.3l from carb to EFI and it will not fire off!! Details:

-2001 suburban PCM
-Truck intake, DBC
-E85 33blhr injectors
-Custom made harness
-TSP224 cam

Here is what we got:
-55PSI at rail
-Spark at cranking
-Noid light "fires" at cranking
-Will fire off with starter fluid
-Only DTC is for no alt wire to PCM
-Have good signal from cam, crank, map, maf
-Used Tech 2 to test injectors and you could hear them pulsing
-Almost 10V at cranking on pinks, oranges, coils and injectors
-Confirmed VATS is turned off
-Tried both the stock 5.3 tune and one for a TSP224 we found on HPtuners forum

Concerns
-I am not using the Pin #9 on the red connector for fuel pump relay (Already had a fuel pump relay from carb'd days.) Could the PMC need to see load/feedback on this pin?
-Injectors are clogged from sitting for ? years

All thoughts and questions are appreciated! Thanks guys!

ijimmy

If it fires with start fluid , ill bet its VATS ,,, I read your post ,, but my tunner also assured me my vats was off when it was not 3 TIMES ,,, your noid lights will flash 3 times with the VATS ON ,, keep cranking and see if it keeps flashing ,,, if it does check to see if you injectors are clogged , then check grounds [ I suspect its not a gound issue because it fires with fluid , but that is a common issue ]

cruisin'73

iTrader: (8)

Thanks Jimmy. We double checked VATS when we reloaded the TSP224 tune, but we will check again that VATS is off.

Talking with a few guys at work, we are brainstorming that the PCM may need to see feedback or load on the fuel pump relay pin #9. And without seeing that load the PCM may restrict or cut fuel entirely. Maybe it was originally part of the fuel cut in the event of an accident? Tonight I am going to try re-wiring my fuel pump relay signal to pin 9 and see what happens!

lizeec

iTrader: (57)

I vote for clogged, dirty injectors, do you know the history on them?

gofastwclass

iTrader: (2)

1 - Make SURE VATS is actually 100% disabled.
* If you have HP Tuners it needs to be disabled under "system" AND in the DTC's.

2 - Pull the rail and test the injectors.


My money is on one of these two. The PCM doesn't care if it controls the fuel or if something else does.

66Chevellelq4

ive jumped my fuel pump relay many many times with a power probe and the car will still fire every time. I dont think that the relay load would be an issue. X2 on clogged injectors

cruisin'73

iTrader: (8)

Popular vote had it right. Clogged injectors. I popped the fuel rail off, disconnected 7 of the injectors and tried a papertowel test: No fuel.

Pulled injectors, boiled them, put 25PSI and brake clean to one and after a couple hundred 12V pulses was able to get it to cycle. With hope I tried a second one and after a bunch of pulses I got a few brake clean drips before it stuck wide open!

Looks like new injectors are in my future!

Thanks for all the help and recommendations guys!