95 S10 TBI (Z motor) intermittent no start

[rknorr]

I have a 95 Chevy S10 pickup with the TBI motor, Z engine code, that has

begun to not start on occasion. The engine cranks but does not fire at all

everything else seems normal. This only seems to happen in the morning so

might be cold related. If the truck starts I can drive it all day without any

starting issues. Any ideas where to begin troubleshooting? Any help will be appreciated.

[MT-2500]

Originally Posted by rknorr

I have a 95 Chevy S10 pickup with the TBI motor, Z engine code, that has

begun to not start on occasion. The engine cranks but does not fire at all

everything else seems normal. This only seems to happen in the morning so

might be cold related. If the truck starts I can drive it all day without any

starting issues. Any ideas where to begin troubleshooting? Any help will be appreciated.

Check for good spark and fuel pressure and injector pulse and squirt when no start.
Do you have any check engine lights or codes?

[rknorr]

Sounds reasonable. Just went outside and the truck started right up even though its 43°F out, pretty chilly for around here!! I noticed the voltmeter on the dash seemed like it was reading kind of high, checked with my DVM and its around 15V. Seems kind of high for a truck that drove over a hundred miles yesterday. I would think the battery would be fully charged already.

[rhandwor]

Originally Posted by rknorr

I have a 95 Chevy S10 pickup with the TBI motor, Z engine code, that has

begun to not start on occasion. The engine cranks but does not fire at all

everything else seems normal. This only seems to happen in the morning so

might be cold related. If the truck starts I can drive it all day without any

starting issues. Any ideas where to begin troubleshooting? Any help will be appreciated.

I would check the grounds alternator bracket,and left cylinder head. If loose will cause all kinds of miscellaneous problems.

[rknorr]

sounds easy enough.

[rknorr]

Originally Posted by MT-2500

Check for good spark and fuel pressure and injector pulse and squirt when no start.
Do you have any check engine lights or codes?

Sorry, I didn't notice you asking about codes. There are no check engine light or codes now or when it won't start.

[rknorr]

Today, no start. Good fuel squirt on start attempts. I'm assuming I have spark since I couldnt get a plug wire off to check. I checked voltages at the two connectors on the coil. With ignition on grey connector had 12 volts on one wire, black connector had nothing on either wire. What next?

[rhandwor]

Originally Posted by rknorr

Today, no start. Good fuel squirt on start attempts. I'm assuming I have spark since I couldnt get a plug wire off to check. I checked voltages at the two connectors on the coil. With ignition on grey connector had 12 volts on one wire, black connector had nothing on either wire. What next?

I looked at a 1995 4.3L wiring diagram but a W couldn't find a Z. It showed a pnk and wht wire to the coil from the pick up coil. I would use a 12 volt test light find the hot.
Put the test light on the other wire have some one crank the engine the light should blink. This should fire the coil.
Call some parts stores and check if they will test the module free.
Haynes should have a procedure to check the coil.

[rknorr]

Originally Posted by rhandwor

I looked at a 1995 4.3L wiring diagram but a W couldn't find a Z. It showed a pnk and wht wire to the coil from the pick up coil. I would use a 12 volt test light find the hot.
Put the test light on the other wire have some one crank the engine the light should blink. This should fire the coil.
Call some parts stores and check if they will test the module free.
Haynes should have a procedure to check the coil.

Truck won't start this morning, tested as above, one wire is hot other does not blink.

[rhandwor]

I think you may have a coil problem but go through the tests for the 4.3L and you will learn a lot and I haven't worked on a lot of this model Chevy. I also have a module testor.


http://easyautodiagnostics.com/gm_ic...n_module_1.php