stumble cold starting

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

captsb890

Member
Joined
Sep 29, 2020
Messages
93
Reaction score
47
Location
Arizona
What causes a cold start stumble Cold meaning here in AZ this time of year -in the 90's---a first start that it stumbles when it lights off-----with foot off pedal-----then I tap the pedal and it catches just fine-----all other starts, hot are normal used to start right up cold on its own-------changed TPS, Coolant sensor, Map, ICM---( it isn't a motor craft--"O" Riley special ---didn't touch the distributor, itself ---or the cap got new plugs, all new wires fuel pressure was 35--held for 15-30 seconds------the engine does have 204,000 on it-----but always started right up---
maybe a motor craft ICM would help ?? no check engine light on----nothing shows on OBD 1 tester--------------?? any hints or should I wait until the weather starts cooling down at night??
 

Motech

Well-known member
Joined
Jun 21, 2021
Messages
494
Reaction score
576
Location
Santa Cruz, CA:
May be tired old Idle Air Control Valve, which is also succeptible to poor ground issues.

Check and clean up (or replace) body ground pigtail connector off battery negative cable.

Clean up throttle body, then reset long term memory with a 15 minute battery disconnect.

Also could be low coolant level. They can create an air pocket near coolant temp sensor and cause excessively rich conditions.
 
OP
OP
C

captsb890

Member
Joined
Sep 29, 2020
Messages
93
Reaction score
47
Location
Arizona
May be tired old Idle Air Control Valve, which is also succeptible to poor ground issues.

Check and clean up (or replace) body ground pigtail connector off battery negative cable.

Clean up throttle body, then reset long term memory with a 15 minute battery disconnect.

Also could be low coolant level. They can create an air pocket near coolant temp sensor and cause excessively rich conditions.
Thank you--I'll check those issues !
 
OP
OP
C

captsb890

Member
Joined
Sep 29, 2020
Messages
93
Reaction score
47
Location
Arizona
Still have the problem on cold start----someone mentioned that it might be the MAP--??as the computer gets its info from the MAP and coolant sensor ( which is new) Do you think I should try a new ICM ? or maybe it is a ground wire on the idle control valve-?? Don't know where that is ?----but---something is causing it and nothing shows up on the OBD 1
 

Tiha

Well-known member
Staff member
Moderator
Joined
Jul 22, 2020
Messages
986
Reaction score
1,022
Location
Midwest
Was it cool and damp, like rainy morning? Or everyday?

Usually the damp mornings, if you have starting issues it is plug wires.
 
OP
OP
C

captsb890

Member
Joined
Sep 29, 2020
Messages
93
Reaction score
47
Location
Arizona
Was it cool and damp, like rainy morning? Or everyday?

Usually the damp mornings, if you have starting issues it is plug wires.
New wires and plugs-----------------I didn't change the Distibutor cap and rotor Do you think is maybe a weak battery---shows 12 volts-? Didn't check the load as I don't have a meter
 

johnnyreb

Well-known member
Joined
Feb 23, 2021
Messages
2,423
Reaction score
1,069
Location
West Virginia
New wires and plugs-----------------I didn't change the Distibutor cap and rotor Do you think is maybe a weak battery---shows 12 volts-? Didn't check the load as I don't have a meter
Check the NEW plug wire tips. Both ends. I bought a NEW SET OF MOTORCRAFT --and they were pushed back aways. Had to pull them out before I got contact. These NEW PARTS --MOST IS JUNK. Better off going to a junk yard and getting parts.
 

johnnyreb

Well-known member
Joined
Feb 23, 2021
Messages
2,423
Reaction score
1,069
Location
West Virginia
Check the NEW plug wire tips. Both ends. I bought a NEW SET OF MOTORCRAFT --and they were pushed back aways. Had to pull them out before I got contact. These NEW PARTS --MOST IS JUNK. Better off going to a junk yard and getting parts.
Also did you CHECK
 

Members online

No members online now.

Latest posts

Forum statistics

Threads
22,516
Messages
135,945
Members
25,118
Latest member
msgsnprtom
Top