1990 geo tracker fuel pump not working.

[whistle80]

Hello everyone!
I have a 1990 Geo tracker M/T 4X4. I have a new fuel pump, new injector, 2 rebuilt ECM's for 89/90 and get no fuel from pump. I checked the injector with a noid light and it works fine. I know ECM's 91+ and different but I plugged it in anyway. When I plug it in and turn the key, I get a working fuel pump. It actually comes on for about 3 seconds. When I plug the correct ECM back in, turn key on, the fuel pump will bump for a fraction of a second...then nothing. I can crank and crank but...nothing. If I pour fuel in the throttle body, it will run all day long. Any positive feedback would be much appreciated.
Thanks

[fixkick]

im too easily fooled with runs on test fuel. ( I KNOW better but was lulled)
the first test (besides compression and spark good, ill pretend it is and that too is dumb of me as , a 50PSI lawn mower engine runs at 50PSI on test fuel , but not your EFI ECU, not at all)
baring that we must look at your injector cranking first... that was bad not to look.
and fail 2, when was the last time it ran as a daily driver. last month , last year>? (bad fuel happens)

lets use the better page.
my injector page
you gander at this single injector cranking and it squirts or not. or looks weak.
see my fast track page, see TBI.

http://www.fixkick.com/INJECTORS/injectors.html#fast

see my 89 differences here. huge list. and is not complete.!

http://www.fixkick.com/specs/89-diffs.html

see all schematics for 89/90 in this PDF i made
has sticky comments too. full schematics are here. end to end.
http://www.fixkick.com/ECU/89/1990-scan-...lpages.pdf

[whistle80]

Thank you for all of the information thus far! The only reason I have a 91 ECM is because I was planning on changing things over from 90 to 91 because of the aforementioned issues. I have a 91 intake manifold, distributor, coil, partial wiring harness, and ecm. I was just thinking that this could eliminate my problem. But I just don't want to give up on the 90 stuff. I just feel that it is something simple and I must be over looking it.

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I will check out the wiring from the corrected diagram within the next day or so.

[fixkick]

if the injector fails to squirt correctly
and fuel pressure is low 0 to 30 PSI is low.
then see if pump has 12vdc cranking.

the best drawing i have , now updated, for voltages.

[whistle80]

Yes, I have a 2 door.
I would love to know the cranking voltage at each pin of the main relay.
I will test everything this weekend and report back.

[fixkick]

the voltages are all there.
but cranking voltage can be 10 to12v.
what ever the battery is , cranking the pump will be, that or 0.5v less. so say 9.5v, in Alaska.
here in texas its 11vdc min.

just check battery voltage before and during cranking to see what she does.
then go to the rear tail light and check the pink wire.
if fuel pressure is at spec. all this is moot.

[fixkick]

http://www.fixkick.com/ECU/89/1990-scan-...lpages.pdf

the set it here.
see sticky notes for clearer, words.

[whistle80]

Thank you, very helpful!!

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What is the best way to test the TPS?

[fixkick]

if you have 12vdc to the pump , this is next?
http://www.fixkick.com/INJECTORS/TBI-conn-1w.jpg

the $20 harbor Fight tool? at the filter, (a new filter works best)

[whistle80]

Just a heads up:
The voltage to the pump was a little more than 10.xxV. My battery may be a little low due to cranking... The pump IS working by the way. I now have to figure out what is not working. As I crank it, I do smell fuel but it just doesn't want to even attempt to run. I borrowed another ecm and main relay...the same thing happens...NOTHING.