Mil Warnings

[Husafan]

I've got an 87 Comanche with a 4.0L swap from a 99 Cherokee. The check engine light has been on since I got it, and the seller's mechanic told me they'd never really looked into it because emissions standards weren't as strict in Texas or Utah. However, now that I have it in Cali, I need to get the light off before I can get it registered.

 

When I first pulled codes, I was getting two: P0132 and P0135. So I replaced the O2 sensor before the cat and the corresponding fuses. Unfortunately, the check engine light is still coming on. OBDII says 0 codes but is showing multiple MIL warnings and I was hoping some people on here could offer some guidance. The following are from the reader, along with my interpretations given the readers manual:

 

0 Codes

MIL On

Monitrs

2 Inc

Catlyst

O2 Htr

4 Ready

Misfire

Fuel

Comp

O2 Snsr

 

Based on my reading of the manual, this means that 2 monitors were incomplete, the Catalyst Monitor and O2 Heater Monitor and 4 were completed and shown wanting, the Misfire Monitor, Fuel Monitor, Comprehensive Components Monitor and O2 Sensor Monitor. I should also mention that the vacuum canister that's normally in the front left of the engine bay is missing (I can take a picture if needed), and this is what the mechanic whom I picked it up from thought was causing the issues. If this is something that will require too much time or expertise to sort out on my own, I will probably end up taking it by the shop later this week. But if this is something I could use as a learning experience, I would love to take care of it myself. To be honest, I don't even know where to start in diagnosing and fixing these monitor warnings, so any help and guidance would be GREATLY appreciated. Thanks!

[ParadiseMJ]

So, let me get this...

 

You have an 87 MJ with a check engine light? Yes, I did get the part about the 99 engine. Did you swap everything, dash, gauge cluster, computer, sensors, wiring harnessses?? Who did the swap?

 

Where do you plug in the OBD II scanner? Where does the scanner get it's information?? My 88 has no scanner port, no CEL on the gauge cluster, no wiring for same.

 

Since the smog man wouldn't be expecting ANY CEL on a pre OBD vehicle...why don't you just remove the bulb?? Why would a mecahnic even attempt to plug in a pre-OBD vehicle. Something isn't right here.

 

Sounds fishy!!!

[Husafan]

For

So, let me get this...

 

You have an 87 MJ with a check engine light? Yes, I did get the part about the 99 engine. Did you swap everything, dash, gauge cluster, computer, sensors, wiring harnessses?? Who did the swap?

 

Where do you plug in the OBD II scanner? Where does the scanner get it's information?? My 88 has no scanner port, no CEL on the gauge cluster, no wiring for same.

 

Since the smog man wouldn't be expecting ANY CEL on a pre OBD vehicle...why don't you just remove the bulb?? Why would a mecahnic even attempt to plug in a pre-OBD vehicle. Something isn't right here.

 

Sounds fishy!!!

 

For all intents and purposes, it can be considered a 99 cherokee. In fact, I probably should have posted this in the pub, since it isn't, technically, a Comanche. The engine, manifold, wiring - everything's been swapped in. The OBDII plugs in right under the steering column. I took it by the shop today and had a more specific reading. Turns out it's the vapor canister, which was left out of the swap. I think my next step is to try and find a vapor canister and then attempt to install it. :)

 

[xjrev10]

So its a 87 MJ titled as a 99 XJ?

 

I know nothing about emmisions laws or anything of that sort but isnt anything 20 years or older exempt? Do the emmision police HAVE to know its a 99 engine/trans/t-case/sheetmetal?

[Husafan]

So its a 87 MJ titled as a 99 XJ?

 

I know nothing about emmisions laws or anything of that sort but isnt anything 20 years or older exempt? Do the emmision police HAVE to know its a 99 engine/trans/t-case/sheetmetal?

 

Actually, it's still titled as an '87 MJ. But here in Cali, it still has to pass emissions. I think it might be a slacker emissions, but it still has to pass. And for that, I am under the impression the MIL has to be off.

[Husafan]

[EDIT] Looking again, I don't see any evap canister either. I guess I'm missing the entire system here. :P So I guess start from scratch installing these pieces according to the diagram?

 

So I went and picked up part #4669475AB - a Canister Purge Solenoid Control. I found the following diagram for hooking it up:

And the following picture of someone's hookup:

 

So I went and tried to find the corresponding connectors and such under my own hood. Here's what it looked like:

 

So, as you can see, I found the loose electrical hookup that connects to the canister (#1 in the image) and I also see a loose hose (#2 in the image) which looks like it might be the right size if I remove what looks like a valve stem from the end of it. However, I certainly don't see two hoses, which I suppose could be expected if they put off bringing the whole purge solenoid over.

 

Based on the diagram I embedded, the top hose should be connected to the evap canister and the bottom one should be connected to the map sensor. First question: does this sound/look right to you all? Second: is that the engine the map sensor is sitting on in the diagram? Is that where I need to be looking to connect the bottom hose? Third and final question: The Comanche also has had a second tank installed. When I was under there, I saw a couple of loose hoses (image below) that I am not sure should be loose. Might they need to be running into this system in some way in which they are not? I ask because the diagram has a couple of hoses going to the fuel tank. Again, any and all help is greatly appreciated! Thanks!

 

[Husafan]

Ok, so after posting at expeditionportal.com, it appears that I will need the entire emissions system from a '99 cherokee before I can attempt to get it inspected. Has anyone done this kind of swap before?

[ParadiseMJ]

What I was saying is that if it is titled as an 87...the DMV, the smog guy, and / or Santa Claus don't need to know that it's a 99 engine (unless of course you tell them). All it really has to do is pass the sniffer test.

[vaquaro]

Here in B.C. we have "Air-Care" testing annualy / bi-annual for '97 and newer ( B.C. uses California Smog Spec.s) . Ever year I have the same situation during testing , they run it on the dyno , then another guy gets in and runs it again , the finally the Supervisor has a go .I ask him "what's the problem " , he replies the software must be defective because your truck's reading are way lower than factory spec.s for this model .......I patiently tell him the replacement catalytic converters are more efficient than the ones built 20 years ago , thus the lower readings . That should be a good thing , but your dealing with beauracrates ( no common sense allowed ) :fs1:

[Husafan]

Just to keep this current, I have started a DIY thread to document the attempted installation of emissions components: http://comancheclub.com/topic/36660-adding-emissions-components-to-my-comanche/