won't start and keeps backfiring.
Apr 7, 2021 at 7:42 PM
Firing order and timing chain
1990 CHEVROLET CHEYENNE
THAYLIA FOBB
- MEMBER
- 1 POST
- FOLLOW
Repair Safety Notice:
This information is for general instructional purposes only. Vehicle repair can be dangerous.
Verify all information, follow manufacturer service procedures, use proper tools and safety equipment,
and consult a qualified repair shop when needed.
Advertisement
Hi,
If you look at pics 1 and 2, they provide the firing order and cylinder location (cylinder 1).
If the spark plug wires were not removed, the firing order shouldn't have changed. Take a look through this link. It discusses the most common causes of a backfire.
https://www.2carpros.com/articles/engine-backfires-while-running
As far as the timing chain replacement, pics 3 and 4 provide the directions and show where the marks on the sprockets should be.
Let me know exactly what is happening. If possible, record what is happening and upload it for me to hear.
Also, I want you to check for diagnostic trouble codes. This vehicle has an OBD 1 system. You don't need 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 do it:
https://www.2carpros.com/articles/buick-cadillac-chevy-gmc-oldsmobile-pontiac-gm-1983-1995-obd1-code-definitions-and-retrieval-method
Let me know if any of this helps or if you have other questions. Also, let me know the codes you find.
Take care,
Joe
See pics below.
If you look at pics 1 and 2, they provide the firing order and cylinder location (cylinder 1).
If the spark plug wires were not removed, the firing order shouldn't have changed. Take a look through this link. It discusses the most common causes of a backfire.
https://www.2carpros.com/articles/engine-backfires-while-running
As far as the timing chain replacement, pics 3 and 4 provide the directions and show where the marks on the sprockets should be.
Let me know exactly what is happening. If possible, record what is happening and upload it for me to hear.
Also, I want you to check for diagnostic trouble codes. This vehicle has an OBD 1 system. You don't need 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 do it:
https://www.2carpros.com/articles/buick-cadillac-chevy-gmc-oldsmobile-pontiac-gm-1983-1995-obd1-code-definitions-and-retrieval-method
Let me know if any of this helps or if you have other questions. Also, let me know the codes you find.
Take care,
Joe
See pics below.
Images (Click to enlarge)
Apr 7, 2021 at 8:34 PM
Advertisement