1990 Chevy Lumina Lumina Will not Start, Just cranks

Tiny
PDIGIACINTO
  • MEMBER
  • 1990 CHEVROLET LUMINA
  • 6 CYL
  • FWD
  • AUTOMATIC
  • 109,000 MILES
I have a 1990 Lumina 3.1L V 6 Euro and it is driving me crazy trying to fix this starting problem. I have troubleshooted everything I know of, but really need som help.

The car ran fine after I replaced the Fuel Pressure regulator about two months. The old one was so bad that the gas went all the way up into the vacume lines. I cleaned out all of the lines, replaced the fuel pressure regulator and it ran fine, for about two months. Then, the car starting to buck, stall and the engine light came on. This happend in a bad rain storm (could the rain have caused these issues?). After the car arrived home, it would not start ever since. I let it dry out for about 4 days.

When I try to start the car, it just cranks.

If I spray starting fluid in the TB, it will run and then stop. Does this mean the Coils and iginition module are good? Seems to be getting Spark and fuel at the injectors.

The car did have one code in the memory. DTC 35, which was the Idle Air Control error. What is this error and does this relate to the IAT sensor? I think this happened when the car starting bucking and starving for gas. I disconnected the battery and the code disappeard.

I have verified the following to be good (I hope, please correct me if I'm wrong):

Replaced the MAP sensor with a new one

Fuel Pressure was at 40 to 41 PSI when testing it, so the fuel pump is working (I hear it energize and the fuel pressure come right up when the ignition is on).

Removed a spark plug wire and cranked. I saw spark.

After seeing the spark, I would assume the coil packs are good?

I connected a LED to the fuel injector harness and when I tried to crank the engine, I saw pulses (Looks like the injectors are getting the signal for spray commands).

I replaced the Fuel Pressure regulator about a month or so ago (it had very similar symptoms). I doubt the fuel pressure regulator could have gone bad again.

I tested the relays for the ful pump and IGN (all good).

All fuses are good.

My questions are:

If the ignition module is bad, will I get spark and will the car turn over with starting fluid (as mine does)?

Does the ignition module have anything to do with Fuel delivery?

If the coil packs are bad, then would not get spark, right?

Could the computer be bad?

Why is it that the spark plugs are not wet when I try to crank the engine? It is like the injectors are not spraying gas into the engine. I do not smell any gas either.

Shouldnt the plugs be wet with gas when I keep trying to crank it over? They are bone dry and not fouled out.

Any help will be greatly appreciated.
Monday, August 4th, 2008 AT 12:43 PM

6 Replies

Tiny
MERLIN2021
  • MECHANIC
  • 17,250 POSTS
IAC(idle air control) is bolted to the side of the throttle body and if it's bad, it can make the car hard, or impossible to start, take it off and check for carbon build up, you can try cleaning it out, but most of the time, replacement is the only fix!
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Monday, August 4th, 2008 AT 12:58 PM
Tiny
PDIGIACINTO
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  • 4 POSTS
Thanks for the quick response. I did check to see if the plunger on the IAC motor worked. It did move as it should when I tried to crank the engine. I did clean it. Is this suppose to spin or just move in and out?

Thanks.
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Monday, August 4th, 2008 AT 1:32 PM
Tiny
PDIGIACINTO
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Another question:
If the IAC motor was bad, the injectors should still spray gas into the engine, right?
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Monday, August 4th, 2008 AT 3:25 PM
Tiny
MERLIN2021
  • MECHANIC
  • 17,250 POSTS
Yes the injectors would work but mixture is way off, pintle should move in and out, not spin. Try unplugging that and the TPS see if it starts.
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Monday, August 4th, 2008 AT 3:30 PM
Tiny
PDIGIACINTO
  • MEMBER
  • 4 POSTS
I unplugged the iac and the tps, but it still just cranks. Any other thoughts? This has really stumped me.

What controls fuel delivery besides the map sensor and computer?

Thanks.
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Monday, August 4th, 2008 AT 4:56 PM
Tiny
MERLIN2021
  • MECHANIC
  • 17,250 POSTS
If the PCM doesnt get a signal from the crank sensor, you will have no spark, and no injector pulse.
Go here to TS no starts.
https://www.2carpros.com/first_things/car_cranks_but_wont_start.htm
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Tuesday, August 5th, 2008 AT 4:07 PM

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