This post isn't thirdgen related but this is the BEST place for info
on G.M. vehicles that I know of.
Have a 94 chevy G20 van w/TBI that starts like new, has oil press
and I can hear the pump priming, then it dies. It starts back up at
once after dieing. Friend brought over his ECM reader or diagnostic
hand held piece of SH** and it says fuel pump relay but I'm not sure
about that and I've come to my favorite site for expert advice being
a 350 TBI is a 350 TBI no matter what it is in.
And I went and bought a Haynes repair manual for it and I can only
find the relay in the schematic!!! no where else in the book even
mentioned, like where it is located, firewall, frame rail,please help.
Sure am glad I'm not having these probs w/my T/A!!! But I went carb
on that one......Thanks

 

have you ever cleaned your iac valve? that could cause similar problems to what you're talking about. if you haven't, I can't explain it in detail but your haynes bible should have the instructions, basically all you have to do is remove it, spray it with a bit of brake cleaner, and make sure not to touch the end that has the spring and the point(the valve, if you will). try it, see if it makes a difference.
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also, if it IS the fuel pump relay, I would think the fuse would go first, and if that did, your car shouldn't start at all.

I could be wrong, but checking the fuse and cleaning the iac valve is a hell of a lot easier and cheaper than automatically assuming it's a relay.

i say this from experience btw, I've changed a sensor or two just trying to fix a problem, when it was something far simpler.

 

Thanks Free, I can relate as I went and bought the relay and well
you can guess the rest. Did exactly what you referenced, bought
something I didn't need.
Well I checked out the fuel system and all is well and then I pulled
the coil to distributor wire off to check to see if I had spark and what
I saw really threw me for a loop, spark for a bit and then none!!!
Spark no spark so now I'm thinking coil but also doesn't the ECM
send the command to the coil? How do I check the coil?,I have
pocket pro volt meter/ohm meter the bible didn't say, only for HEI
coil in the distributor, Oh man when it rains.

 

i haven't done a lot of work myself with voltmeters, but it would seem to me that you put the negative(black) to ground(a piece of metal) and connect the red wire to the metal tip of the coil, the voltmeter itself should probably be set to the highest volt setting you have on there, as the stock coils generate something like 30,000 volts if I remember correctly. however, since the truth is I DON'T know for sure of what I'm talking about, DON'T do that until you get varification from someone who actually knows.

what I WOULD suggest doing is checking the connectors to the coil for starters, the clips that hold them down have a tendancy to break(mine are), and they may have come loose, I don't know for sure.

you could also go out and buy a new coil if you like, and return it if that's not the problem, but one thing I can say about coils...from my experience, when they go bad, they flat out stop working.

but who knows, check the connectors, temporarily replace the coil if you like, but if you can, talk to someone who has worked a lot more with voltmeters and get them to check it, because if it's showing no or very low voltage, then the issue may be obvious.

 

Don't try to test secondary voltage with a voltmeter.

Get a calibrated spark tester, they're a few dollars at any parts store.

 

oh, also, I highly doubt it's the ecm that's causing problems, but i don't really know how to explain why...just stick with the easy possibilites first.

if that coil is stock, then there's a fair chance that that is the case.

in which case, run out and buy an msd one, I've had no troubles with mine, and the car simply seemed to run smoother once it was installed.

 

checked pretty most everything, had budy come over with
$9k Snap-on total station modis (which I'm told is the best)
on the market for analyizing car probs and it still couldn't
come up with anything either except ECM maybe but it did
not say why or what so I'm still screwed cause I really am
not sure about that ahs any one ever run into this (spark no spark)
prob before or do I need to post in a diff tech board like engine?

 

go ahead and try a few different boards, there's nothing wrong with asking as many people as possible..

 

try putting the est in bypass, I have seen modules cause this problem before

 

In order to properly find the problem you need to start at a certain point. You have spark at the coil for a couple seconds then what. You need to verify that you have a ignition pulse and 12 volts. With the key on engine off you should be able to take your test light (or voltmeter) and see if both light up. They should have 12 volts on both sides. If not you have a wiring problem that goes back to the battery. Now to test for pulse is pretty easy while the car is cranking you should have 12 volts on one side and the other should be switching on and off 12 volts (blinking light). Once you figure that out you should have a pretty good idea what the problem may be. Remember ignition systems begin at the battery.

 

Thanks all, I got it figured out, control module, and gave it a
complete tune and wow!!

 

@w1964bgta what control module was it? i googled control module and it came up with couple different ones.

 

He posted that 18 years ago and hasn't logged onto this site in the last 16 years. Good chance he isn't going to answer you.