Need some EFI help

blue66tang

Founding Member
Jan 20, 2001
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Medford, OR
I am currently swapping a 89 5.0 into an 84 cj7 and would like to know what are all the sensors i need to make this thing run properly. I am getting rid of the smog stuff, as well as teh A/C. So basicaly i need just the essential sensors. Thanks.
 
Off the top of my head...

O2's
ECT
ACT
TPS
MAF
EDIT: VSS

That's all I can think of without emissions.

What computer do you have?

Sounds like a fun project, how far along are you?


jason
 
Thanks, can you also tell me what these are and where they are located. I got this whole engine and wiring as a basket case, so i am triying to peace it back together. I basicaly have the engine completley back together and now am working on the wiring and then dropping it in.
 
LOL
Sorry bout that :D


ECT - Engine Coolant Temperature Sensor; should be mounted in the heater tubes, on the passenger side of the enigne along the lower intake manifold.

ACT - Air Charge Temperature Sensor; should be threaded directly into the lower intake manifold IN one of the intake runners. I don't remember which runner on the stock manifold though.

O2 - Oxygen Sensors; If you just have the engine you may not have the O2's, as they are mounted in the midpipe near the header flange, but before the cats.

TPS - Throttle Position Sensor; Located on top of the Throttle Body

MAF - Mass Air Flow Sensor; Mounted in the intake tubing, just aft of the air filter box. If the enigne is speed density, you won't have a MAF.

VSS - Vehicle Speed Sensor; this will be mounted in the trans I believe. It tells the computer how fast the car is moving, which is used for things like throttle kickdown rates, timing advance, and fuel. This sensor has a minimal affect most of the time, but sometimes it can cause major issues if not installed.

Computer?
If you have one... What is the 3-4 digit catch code?
A9L, A9P, etc.
This will let us know some good details on what you have.



jason
 
I have a A9P computer. Will this one work in a manual transmission. I believe it came out of a automatic. I believe i have all the sensors except the vss and the BAP. Are these sensors necisary. Basicaly i want evertyying to make this thing rung normal, except the smog stuff. Thanks for your help
 
The BAP!!!
I knew I forgot something!


Yes you will need the BAP, and really there is no reason not to run the VSS.

The A9P is an automatic computer, but should work quite well with the manual trans.
(it isn't recommended to run an auto trans with a manual computer though).


Keep us posted on your progress,

Do you have any pics?


jason
 
Vehicle Speed Sensor (VSS) is an electronic sender mounted on the speedo pickup gear on the trans. It works the cruse control for both 5 speed and auto trans cars. The VSS is used to tell the computer to speed up the idle as you slow to a stop. This helps keep the engine from stalling when you slow down for a stop sign or stop light. It serves as the carrier for the speedo pickup gear. A single small metric bolt holds the VSS sensor in place.

The VSS sensor looks like this:
vss311.jpg


Tbe VSS equipted cars have a speedo cable with a different fitting on the transmission end of the cable. It is the fitting on the LH side of the following picture.

s09.jpg


Locate the VSS sensor on the driver’s side of the transmission tailshaft housing. The speedo cable housing will be secured in the VSS sensor with a hairpin clip Do not remove the clip!!!: The hairpin clip stays in place. If you remove it, the odds are that you will not be able to get the cable to stay in place on re-installation. Pull firmly straight back on the cable housing and it will come out. A considerable amount of effort may be required to get the cable out of the VSS sensor, but it will pull out.

Installing the speedo cable into the VSS sensor: push the cable housing assembly into the VSS sensor until it snaps in past the hairpin clip.

In order to run a VSS sensor on a Jeep, you may need to have a custom speedo cable fabricated. Most of the larger speedometer shops can do this. See http://www.gaugeguys.com/ratioadapt.htm for more info.