Intermittent no crank no start in cold weather and limp mode in hot weather?

Hi,

Wow, you can't win regardless of the temperature. LOL Have you checked for diagnostic trouble codes that may point us in the right direction? I believe this still has the OBD1 system and doesn't require a scanner to retrieve codes. All that is needed is a short jumper wire or even a paper clip.

Here is a link that explains how to check it:

https://www.2carpros.com/articles/buick-cadillac-chevy-gmc-oldsmobile-pontiac-gm-1983-1995-obd1-code-definitions-and-retrieval-method

Please keep in mind, 1995 was a transitional year, so it may actually have an OBD2 system. Let me know if that is the case. Also, let me know if you have scanned for codes already.

At this point (in theory), I am questioning if there is an issue with the coolant temperature sensor. If it isn't sending correct information, the air/fuel mixture could be off and cause a hard start when cold or an issue above the temperature. It is a theory at this point.

Let me know.

Joe

I've scanned for codes no codes replaced temperature sensors. It's been like this for 2 years all summer long in limp mode now yesterday getting cold no more limp mode unless it's warm out and starts fine warm weather but now cold it no crank no start until later in day when sun out.

The one thing that can cause the no crank condition is the relay. Have you tried replacing it? Also, when you scanned for codes, did you scan the can-bus for codes stored in other modules?

As far as limp mode, do you mean it is staying in one gear (for example 2nd gear) or is the engine restricted to a specific RPM before it won't increase?

Let me know. Also, tomorrow if it is cold and won't crank, place it in neutral and try. Additionally, confirm the gear indicator is showing the correct selected gear.

Let me know.

Joe

No codes, limp mode, no down shift to first gear and no overdrive unless turn off on.

New relays.

Okay. If the starter doesn't work when cold but does when it's warm, at some point, I suspect the expansion and contraction of a connector are causing the different issues. Have you checked to make sure the ground between the battery and engine block is in good condition?

Let me know.

Joe

Yes, grounds good has to be in rear speed sensor or ignition switch.

Hi,

The switch could make sense, but the speed sensor is unlikely. (but anything is possible) I am going to forward this post to the site owner. He is excellent with these vehicles. Maybe he will have a different idea.

Take care of yourself and we'll be in touch.

Joe

When you say "no crank no start " do you mean the engine will not crank over or the engine cranks (starter working) but will not run? If it is not running, I would do a fuel pump pressure test to see if the fuel pump is any good.

Here is a guide to help:

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Ignition ON Engine OFF .................... 62-90 kPa (9-13 psi)

Please go over this guide and get back to us.

As I said before only no crank no start in cold weather below 40 above 40 it starts fine.

And below 40 no limp mode but above 40 limp mode been like this over 2 years just passed smog today.

It sounds like the starter motor is bad. To be sure when it does not crank over, let's use a test light on the trigger wire at the starter solenoid. This guide can help us:

https://www.2carpros.com/articles/starter-not-working-repair

Also, it could be the battery cables so well so inspect them for corrosion and replace them as needed. This guide can help walk you through the steps of changing the starter motor out:

https://www.2carpros.com/articles/how-to-replace-a-starter-motor

Please let us know what happens.

It's not starter or cables my main problem is limp mode in cold weather.