1987 tbi 350 cranks wont run

[beavo]

 ???i have an 87 tbi that up and quit the other day it backfired once or twice then quit i figured it was the fuel pump as it would not start off the key but prime it and it would run until it burnt the prime i changed the pump the brand new pump wouldnt run put another in it now it  pumps fuel but truck still will not run it has pressure up to the tbi i checked that the injectors have fire i checked that and with it running as long as you keep pouring gas down it i guess that means all the ign is good please help as i am at a loss thanks.?.

[Blazin]

Had a Lumina van once that had similar sounding issue. It turned out to be a bad ignition module??

[beavo]

ok thanks for the help ill try that

[Lt.Del]

wouldn't a bad ignition module cause it to not have spark? Checking for spark should tell ya if that is good, i believe.  But, you have spark because when you pour gas in it starts.

[beavo]

well thats what i thought to that the module was good cause of it running but i just had it tested and of course it was good i also took the ecm out and put it in a van that my father owns and it runs like a top so now im back to square 1

[Grim 82]

What is it reading for fuel pressure? Did you look at the injectors with a timing light to check the pattern?

[beavo]

it doesnt have a place to check the pressure and no i didnt check it with a light because there is no fuel out of the injectors at all and to make sure i placed a paper under the injector and had my wife crank it and there was no fuel on the paper thanks

[Blazin]

My van died, I got it home thinking fuel pump. Sprayed some gas out of a squirt bottle into the throtle body it fired right up. Did that several times. Was dark so next day I decided to investigate a little more. Sprayed gas in, and it wouldn't run. Checked for spark had none.

[VileZambonie]

Check for injector pulse. Use a noid light or 12v test light. Unplug one injector connector, key on engine off, test light to ground probe both terminals one should illuminate the test light. If ok put test light to B+ and touch the other terminal which did not illumiate (the ground side of the injector harness) have an assistant crank the engine - observe your test light. It should blink. -Report

[Irish_Alley]

do you have a vats not sure what years they started in wana say newer than ours but not sure? if not beavo it might be a pain but swap out distributors with thee one in your dads van. pick up coil sends a signal to the icm the engine is turning to fire the injectors icm then sends the signal to the ecm. you tested the icm and ecm but not the first step the pick up coil just something to think about. also the oil sending unit tells the ecm when it senses 4psi to turn on the injectors might be another parts swap while you’re under the hood

[beavo]

ok so i had tried making sure that the injectors were gettin fire by running the test with the light before i made this  but not to make sure it pulsed the b+ your talkin about where is that and for the oil press i have a gauge in the truck and it shows some where around 18lb when cranking but that doesnt mean that the press switch is bad tho does it  is there any other way to check the pickup coil and as for swapping the dist id like to make that a last resort and with many future days of frustration i may go ahead and do it lol but anyways thanks for all the help yall i really appreciate it

[Lt.Del]

check to ensure your spark plugs are getting spark.  Take one plug out.  Put the plug wire on that loose plug. Hold the plug tip up against the metal engine...block, head or some place that will ground out the plug tip (that's what happens when the plug is in it's correct postion--it grounds via the threads in the head).   Have someone crank the engine--but, hold the plug with a rag so as not to shock you through the plug wire.

You should see a spark jump accross the gap of the spark plug if you keep it held against the metal engine.

If not spark, it could be pick up coil or not getting volts out of distributor.

[VileZambonie]

ok so i had tried making sure that the injectors were gettin fire by running the test with the light before i made this  but not to make sure it pulsed the b+ your talkin about

So are you saying you performed the test I described? Yes or No? If you did what are the results? You need to check the injector driver circuit.

[beavo]

i did do the test you are talking about i did it before i started asking for help on here i took my test light turned the key on took off my injector wires and checked the wures with the light one of them was hot with the key on when i had my wife crank it i tried the other wire cause the one that was hot with just the key on didnt pulse the other wire did nothing no pulse no nothing but i was asking about the b+ you mentioned whats that because i am now not sure if i did exactly what you are talking about and also what or where is the driver circut htanks again

[VileZambonie]

B+ means battery positive. B- means battery negative. So if you have your test light connected to B- anything that is B+ will illuminate your test light that you probe. If you have your test light hooked to B+ anything that is grounded will illuminate your test light that you probe.

If you verified B+ at the injector harness but didn't verify the injector driver circuit by checking for the presence of ground with your test light then you need to do that.