Ck z28

My 86 I roc-z tpi 305 won't start I need help the car was fine The last time I drove it then Monday I went to start it it tuner over but no start plz help I'm thinking about doing a swap to carb if I can't get the car running soon

mcgarnicle

iTrader: (14)

Check the basics, fuel pressure (44psi+/-), spark, fuel injectors pulsing.


Quick check I usually tell most people with no start is to watch the tach during crank, it should bounce, if it is completely still than your distributor is not sending a pulse signal to the ECM.

thtanner

iTrader: (1)

How are you going to do a carb swap if you can't even post relevant information on this thread about your car not starting?

Think about that.

I'm going to go out on a limb here and say it's easier to fix your current problem than to introduce new ones by trying to do a carb swap.

You gave no indication of the following. This basic info is required for anyone to help you...

• Fuel Pressure
• no fuel pressure gauge, ok... did you at least hear the fuel pump prime?
• Is the Security light staying illuminated on the dash? You should be Pre-VATS so I have a feeling this won't affect you.
• Spark?

Ck z28

Sorry for not giveing enough information about the car. No pre vat It's
a stock 86 tpi 305. Things I checked yes my fuel pump come on fuel pressure was 45psi. Each fuel injectors ohms was 16 I have pulse. ignition module is gd. Things I changed ecm. Cap and rotor ignition coil

mcgarnicle

iTrader: (14)

Do you have spark?

fervernt

Pull one of your plugs, leave it in the spark plug wire, hold it to a metal piece on body, have someone crank the car while you watch. You should see a visible spark. If you dont, are the plugs fouled? check the wires for obvious damage. The icm failing is common, you said it is good, but how do you know, did you replace it? wires and plugs would usually make the car run rough first and cause driveability issues. not just cause it to not start overnight. Also, I know you tested the fuel system, but you should try spraying some starter fluid in there anyway, it would confirm the injectors aren't clogged or something.

Ck z28

Yes I have spark

Ck z28

I took the icm to aoutzone and had them check it when I spay start fluid still no start

mcgarnicle

iTrader: (14)

If it will not fire with starter fluid then you either don't have spark or your getting really weak spark.

You mentioned changing the ECM what year is it out of? Same PROM from your 86?

Based on your information it should run. You have proper fuel pressure, you have spark, and your injectors are pulsing. So unless your cylinders all lost compression it should run.

Clint Crawford

i bought a 1990 iroc last night it ran "ok" missed i little on the way home thought maybe just old gas. fired it up a couple times last night no problems starting. this morning to try to fire it and it wont start its turning over and will run on starter fluid but wont idle and cuts off. where do i go from here why would it crank last night but not today?

Ck z28

do,you,here your fuel pump come on

Ck z28

Yes same prom I got the ecm from autozone

Clintandthebird

Yes fuel pump comes on. I got it running some how. It still picks and chooses when it wants to crank. It misses a lot thought where should i start. Tune up?? Plugs wires cap and button? Or is it a vacuum nproble. It doesn't really want to idle at all. And the pedal is hesitant.

Ck z28

I think I'm getting weak spark when I pulled the spark plug wire to test for spark the spark was yellowish orange I thing I'm going to bye a new icm