Carburetors Carb discussion and questions. Upgrading your Third Gen's carburetor, swapping TBI to carburetor, or TPI to carburetor? Need LG4 or H.O. info? Post it here.

mixture control solenoid wont cycle

Thread Tools
 
Search this Thread
 
Old Oct 19, 2010 | 08:09 PM
  #1  
imboredx0504's Avatar
Thread Starter
Junior Member
 
Joined: Apr 2010
Posts: 19
Likes: 0
mixture control solenoid wont cycle

im trying to get my cart to pass inspection (NJ) so i decided id have to put the old q-jet back on. the problem is i have cut most the wires to the ecm because i didnt really need the ecm after my rebuild. but now i do. i used schematics and got my 02 sensor and 02 sensor ground wired. along with the tps, mcs, and the two engine ground wires from ecm. the problem is i have voltage present at the mcs, and when i run a jumper wire to ground for it. it will click. but when wired to the ecm it will not. the solenoid has 25 ohms of resistance and specs call for atleast 10 ohms. any ideas? must i wire every part for the ecm? if so im beat because i pulled mostly everything off during the rebuild.
Reply
Old Oct 19, 2010 | 08:58 PM
  #2  
Apeiron's Avatar
Moderator
 
Joined: Jan 2000
Posts: 20,981
Likes: 11
From: Mercedes Norte, Heredia, Costa Rica
Car: 1984 Z28 Hardtop
Engine: 383 Carb
Transmission: 4L60
Axle/Gears: 3.54 Dana 44
Re: mixture control solenoid wont cycle

Computer control is all-or-nothing.
Reply
Old Oct 19, 2010 | 10:09 PM
  #3  
imboredx0504's Avatar
Thread Starter
Junior Member
 
Joined: Apr 2010
Posts: 19
Likes: 0
Re: mixture control solenoid wont cycle

i believe that is true to a point. i just watched a gm training video on the c3 ecm system. it says that the input sensors for the fuel delivery system are the baro sensor, manifold absolute pressure (MAP) sensor, throttle positioning sensor, oxygen sensor, temperature sensor, vehicle speed sensor, and tach signal or engine load. and that is all processed to determines the operation of the mixture control solenoid at 10 times per second. so i figure if i can wire those sensors in, the ecm should be able to process the information and send it to the mcs. hopefully it works. im just hoping the vehicle speed sensor still works. i never messed with it but removed an after-market alarm that was wired like a rat nest under the dash before i bought it.
Reply
Old Oct 20, 2010 | 03:07 AM
  #4  
DoubleV's Avatar
Member
 
Joined: Jun 2009
Posts: 218
Likes: 0
Re: mixture control solenoid wont cycle

Originally Posted by imboredx0504
i just watched a gm training video on the c3 ecm system.
I wouldn't mind seeing that video if it goes into great detail. Where would one get a copy of this?
Reply
Old Oct 20, 2010 | 06:56 AM
  #5  
naf's Avatar
naf
Supreme Member
20 Year Member
iTrader: (7)
 
Joined: May 2004
Posts: 5,338
Likes: 73
From: Lexington, SC
Car: 1987 SC/1985 TA
Engine: 350/vortec/fitech
Transmission: T56
Axle/Gears: 3.27 9-bolt
Re: mixture control solenoid wont cycle

Voltage at the MCS does not mean the ECM has power. The power lead to the ECM is the single wire coming off of the positive battery terminal running near the fuel lines.

The computer switches the ground to the MCS. The MCS is powered off of the engine controls fuse under the dash.

The ECM will work without the EGR or AIR systems hooked up. It will also not know if the bump solenoid or TCC lockup is connected.

There should only be ONE wire to the O2. It grounds through the mechanical connection.
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Fronzizzle
Electronics
13
Feb 9, 2017 09:31 AM
skinny z
Carburetors
11
Sep 29, 2015 11:25 PM
amcnellis
TBI
6
Sep 16, 2015 04:16 PM
Rally Smith
TBI
10
Sep 14, 2015 06:59 PM
dbrochard
Transmissions and Drivetrain
1
Sep 7, 2015 09:41 AM




All times are GMT -5. The time now is 03:56 AM.