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Firing order

NCSUcherokee said:
If the distributor was 180 out (my original problem), it wouldnt run at all. the engine just runs indescriminatly bad no matter what i change. i wish i could talk to the original owner and ask her what she did to this thing.
Click to expand...

I dunno bout XJ's but I've put dist's in 180 out and had the vehicle run. Like crap but they ran.

Sarge
 
langer1 said:
I think they fired two cylinders at the same time
Click to expand...
If that's true, that's gotta make some hellish shaking forces.

It would probably be lot the old John Deere Model "A" tractors with the two cylinder engine. When they ran (even at speed) you could COUNT the firing pulses, and when pulling a load, even FEEL the surging when the piston hit the power stroke.

Ton's o' torque, but not real smooth. They also used a MASSIVE flywheel to compensate for the irregular vibration.
 
langer1 said:
This may help some.
firingorder.jpg
Click to expand...
I'd say that won't help at all. It doesn't agree with the real world.

A 1990 is a Renix, the same as an '88. I just went out and checked both my '88 XJ and my '88 MJ. They are almost exactly the same. Here's how they shape up:

Viewed as standing at the right front wheel and looking across the distributor toward the engine, #1 is at lower right, about 5 o'clock. #5 is at lower left, approximately 7 o'clock. (On the MJ a line through #1 and #5 is EXACTLY parallel to the block. On the XJ the distributor body is "clocked" very slightly counter-clockwise compared to the MJ, so #1 might be at like 4:45 rather than 5:00 o'clock).

On both, the wire for the camshaft pickup is located between #1 and #5, and the cap screw is located between #5 and #3.

This is not even remotely close to the illustration. Both of these vehicles run well. The XJ has been this way for 250,000 miles and gets over 20 MPG. The MJ was bought used, the distributor hasn't been touched since I bought it, and it gets 19 to 20 MPG on the highway with the tailgate up.

I think it's safe to use this as a guide to setting yours up.
 
badge714 said:
http://www.angelfire.com/my/fan/dist_index.html Just a thought maybe this is of help. badge714 [email protected]
Click to expand...
This describes indexing for an HO. The reference to the rotor pointing to 5:00 o'clock is correct, but the location of the cam sensor before #1 does not agree with the way my Renix distributors are running. I know the XJ is factory original because I bought it new and I know the distributor has not been out of the engine.
 
Thank you Eagle, The good news is I havn't had it set up wrong the whole time. The bad news is I havn't had it set up wrong the whole time. Back to the drawing board.
 
Here is a new development.

After fiddling witht the distributor for an hour or so, i am completely convinced I have it right. So i let the engine try and run for a few minutes while trying to run some other diagnostics and i notice some smoke comming from the back end.

short version is the exhaust was getting so hot it was causing the shock boot it was running near to start smoldering. It also melted the hurculiner and the seatbelt above the muffler while running no more than 4 minutes.

I also got hit by some rusted metal flakes while standing behind the exhaust, so this leads me to belive that it is clogged I am going to go check it out after it cools down, but if this doesnt pan out, what else can cause extreme exhause temps?
 
Engine is running very rich. Any un-burnt fuel is burnt by the cat.

Sounds like ECU is in open mode timimg is not correct. fuel injector stuck open?
 
NCSUcherokee said:
Unplugging the CPS and TPS do absolutly nothing, which i find odd. I am getting to the point where i will turn my attention to the fuel because that is the last unchecked area. I have been running it jumped off another vehicle so i know it's not the battery
Click to expand...
These is importaint because it means the ECU is in open mode and not reading the sensors.
 
NCSUcherokee said:
any info on a cause or a fix?


I checked the exhaust, it's not causing the problem.
Click to expand...
The last 31 posts were all a possibilities, check the timing.

It sounds like the ECU is not timing on startup. Causes could be no "cam POS" or "no crank POS" input.
 
langer1 said:
The last 31 posts were all a possibilities, check the timing.

It sounds like the ECU is not timing on startup. Causes could be no "cam POS" or "no crank POS" input.
Click to expand...


I have tried setting up the timming with 2 different distributors, so im willing to bet it isnt the camPS. I flipped the distributor 180 today and tryed a few positions, which yielded a no-start on all of them, so i will cross that one out with a pencil. Tryed unhooking the exhaust; didnt do anything except make it louder, so it isn't clogged as i thought. The CPS ohms out at 275, which is whithin tolerance.

i am running out of ideas.

I do have another CPS that i can try, but i'm unsure of its condition
 
If the CPS were bad it probably wouldn't start at all.

Can you get it to a service facility where you can hook it up to some sort of an analyzer? Doesn't have to be one that reads the Renix computer, just find a place that can run a sniffer on the exhaust and try to figure out if it's running super-rich.

How's the oxygen sensor?
 
275 is very close to being out of tolerance, I would feel better if it were 175.Don't forget there is a tolerance in your meter so your reading of 275 could be 300 or more.

Either way, if you put a timing light on it you will be able to tell if it's in time.
The ECU set's the timing on every start up by counting pules from the Cam pos and Crank pos. If it don't get all the pulses it guesses, untill the engine starts.
Also check start relay treminal 30L has a wire that goes back to the ECU that tell's it your cranking and to do it's timing thing.

Anyway it looks to me like the CPS in working but not good enough.
 
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