3.4 swap into 1985 Jeep Cherokee questions?

[cardana24]

VSS wont mater as long as you don't drive. Choppy running could be attributed to many things. First on the list would be incorrect firing order and poor timing. It can also be caused by a rich fuel mixture but with EFI there is no way to screw that up unless you have serious sensor problems. So check or replace the ECT sensor. To test it measure the pins you should have 3400 ohms at 21*C (70*F)

Do you have a diagram of the firing order? The only thing relating to this I have seen is the Haynes manual. I will check this tonight, and I was wondering too, if a faulty map sensor would cause it to run crappy/choppy as well?

[geoffinbc]

The Firing order is 123456. The Number 1 cylinder is the passenger side front. You converted to coil packs right? Then they should be paired. 1-4 2-5 and 3-6

The intake manifold is also marked at the intake runner. A map sensor will cause a shitty idle and very poor overall operation.

[Canyonero]

VSS wont mater as long as you don't drive. Choppy running could be attributed to many things. First on the list would be incorrect firing order and poor timing. It can also be caused by a rich fuel mixture but with EFI there is no way to screw that up unless you have serious sensor problems. So check or replace the ECT sensor. To test it measure the pins you should have 3400 ohms at 21*C (70*F)

I don't have VSS hooked up. Might explain some idle, MPG, and CEL issues (idles high after driving, 13-14MPG, frequent CEL). I've been meaning to figure that out. What color is the VSS tail? Most of my labels came off.

Look at the Sensors 101 video here:

http://www.advanceautoparts.com/english/youcan/mediaplayer/mediaplayer_clinics.asp

[Canyonero]

I believe the VSS is required of you have the EGR wired in, which I don't. I don't seem to have a VSS tail from the ECU. I just dug it out of my old harness as I plan to wire it into my FIS harness. Same with the canister purge.

[Canyonero]

I found this info here, looks like they make swap parts for putting GM V8s into Jaguars: http://www.jagsthatrun.com/Pages/Spe...eedometer.html

Even more here (pdf): http://www.jagsthatrun.com/V8-chapte...ed-Sensors.pdf

Basically, the VSS tells the ECM how fast the vehicle is going. Most people think the VSS is only used for the lock-up torque converter. The VSS is also used to control the EGR valve, the charcoal canister purge valve, the electric cooling fans, idle speed, and air/fuel ratio. This is all explained in the Chevrolet shop manuals.

It must be emphasized that the VSS is used to control the idle speed when the vehicle is moving. Without the VSS, a vehicle may have stalling problems under certain conditions. Needless to say, this is dangerous. Raising the minimum idle speed with the adjusting screw can eliminate stalling, but the engine will still not run optimally without a VSS.

A lot of people think that running "closed loop" is best for fuel mileage. Closed loop simply means that the oxygen sensor is being used to monitor the fuel/air ratio. Some of the Chevrolet fuel-injected engines are programmed to run lean under certain conditions (called "highway mode") to improve fuel mileage during steady cruise conditions. Without a VSS, the engine computer (ECM) will not get the correct signals to run the engine for best fuel mileage. There are a lot of programs in the ECM that depend on the VSS. For best operation, the VSS needs to be connected and functioning.

There are four types of VSS signals required by the engine computer (ECM):

1. The two-pulse (2000 pulses per mile) square wave (D.C. current or direct current) used on all TBI engines through 1992, all computer-controlled-carbureted engines, and on 1985–1989 TPI engines.

2. A four-pulse (4000 pulses per mile) sine-wave (A.C. current or alternating current) signal is required by the 1990–1993 TPI, 1992–1993 LT1 engines, and 1990–1993 Camaro 3.1/3.4 V6 engines.

3. A 40 pulse per driveshaft revolution speed sensor used on 1993 and newer trucks with automatic transmission, 1994 and newer rear drive cars (Camaro, Corvette, and Caprice) with the automatic transmission.

4. A 17 tooth per driveshaft revolution speed sensor used on 1993–1997 LT1 engines with the Borg-Warner 6-speed transmission. An 11 tooth reluctor ring is used on 1993 LT1 engines with the Borg-Warner wide ratio (3.35 First gear) 6-speed transmission.

[cardana24]

can someone varify if my picture in the haynes manual is correct. Right now I have my coils set up this way. Starting at the one closest to the passenger side they are set up 1/4 then 3/6 then 2/5 closest to the driver side. so if you look at the wires in a straight row it is 1,4,6,3,2,5 Is this correct?

[cardana24]

also I checked the secondary resistance on the three coils and they were all in spec.

I did not check the primary resistance since I would need to remove the coils to do that and I did not get around to it tonight. How important is this?

When the engine is running it goes put, put, put out of the exhaust like the exhaust is pulsing.

[bszopi]

[cardana24]

....and as for the cylinder numbers. 1-3-5 are on the right/passenger side correct?

Also with the coils the prongs where the wires connect should be closer to the firewall correct? Rather than closer to the radiator?

[cardana24]

any help guys? This is not make a lot of sence to me.

Also I bought a code reader thing and when I plug it in and switch the ignition on it just makes the CEL light up...it does not flash any codes. So how do you pull codes on a 3.4 if that reader will not work? In the manual that came with the reader it says it works on 3.4 Camaro engines.

[Canyonero]

I don't know, what reader did you get?

Can I borrow it when you're done? I get CELs all the time. Hoping they go away when I get my EGR and stuff hooked up.

[cardana24]

http://www.amazon.com/Equus-3123-GM-Code-Reader/dp/B000EVU8C0/ref=pd_bbs_sr_1?ie=UTF8&s=automotive&qid=1223576517&sr=8-1

I got this one along with a ford scanner on ebay for ~30. In the manual it says that it works on the 3.4, but I don't get any sort of flash code.

[Canyonero]

Hmm, I don't know. I have a nicer Actron scanner, but it's only OBDII. The hybrid OBDI&II ones that work on near everything are more spendy.

I bought one of these but changed my mind and returned it:

http://www.amazon.com/Actron-CP9190-AutoScanner-Diagnostic-Capability/dp/B000KGCUMA/ref=pd_bbs_sr_1?ie=UTF8&s=automotive&qid=1223577308&sr=8-1

I have one of these:

http://www.amazon.com/Actron-CP9175-AutoScanner-Diagnostic-Post-1996/dp/B000FJS8O6/ref=sr_1_1?ie=UTF8&s=automotive&qid=1223577341&sr=1-1

[cardana24]

Hmm, I don't know. I have a nicer Actron scanner, but it's only OBDII. The hybrid OBDI&II ones that work on near everything are more spendy.

I bought one of these but changed my mind and returned it:

http://www.amazon.com/Actron-CP9190-AutoScanner-Diagnostic-Capability/dp/B000KGCUMA/ref=pd_bbs_sr_1?ie=UTF8&s=automotive&qid=1223577308&sr=8-1

I have one of these:
http://www.amazon.com/Actron-CP9175-...3577341&sr=1-1

I have an ODBII scanner, I know that will not work with this. Do you have a scanner or a method that actually works on reading the codes from this ECM?

[Canyonero]

I don't... I went to the local Shucks and tried to get my code read (free), but I didn't have the VIN# to put in the device.