thank you for bringing me to your thread. I skimed through and found that I have a lot of work ahead of me. mine starts and runs most of the time, but every now and then it will crank and not start. It starts eventually, later that day or sometimes 5 days later. Im going to start with the grounds because of the oil and grime under the hood. Ill get back to ya later

 

Quote from 5-90
"1) Check the actual resistance of your ballast, it should be stamped on one of the terminal tabs. It's not going to be very high - somewhere between 0.5 ohm and 2.0 ohms, IIRC"
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Hey guys, hope you are doing well.

First off, I have a question..or a few.

I tested the ballasts old and new, with my uncle's multimeter and a new one I picked up today for only 3 bucks...if I had known I could get one for so cheap I would have a while ago!

I think his is a bit off b/c when I set it to resistance and put the leads together it didnt display zero like the new one's manual said it should and my new one did.
It wasn't far off around 0.4 or 0.5 but it does vary a bit.

So I tested the old and new resistors with the new multimeter and both read 0.00 which confused me a bit.

With my uncle's meter the old resistor measured around 2.2 and the new 6.2

5-90, You mentioned the stamp on the terminals-the new one has a tiny stamp on the bottom of one terminal that says 5.
The old one is stamped in the middle of the ceramic piece with an ohm sign and 1.1 next to it.

So now I'm a little more confused....I'm guessing both resistors are good but why is my new multimeter testing them both at zero? Is the meter bad?
I can understand because of the price....but I got it at harbor freight and that store seems pretty awesome! They do have some crazy stuff so I'm sure some is not very high quality.

My uncle's meter is at least hitting somewhere in the area of what's stamped on each resistor and it was a little high anyway and likes to jump around alot.



As for the grounds finished both of them tonite after a few trips back and forth from the hardware and the auto parts stores.

Still no start though....cant say I'm suprised and now I know grounds aren't the problem!
I wasnt able to check for spark as I didnt have an assistant but I'm pretty sure that's still the issue.
I will check it tomorrow night to be sure.
If you guys have any advice as to what to do next it's appreciated as always!
Take care and have a good one tomorrow, thanks for listening!

 

Just read your message!
You never know you might get lucky!
These guys have been a great help so I'm very thankful, I try to do everything myself but with this one I'm a little over my head! My goal is to do everything myself in the garage and if I can do that I'll be happy....or buying a new vehicle-hopefully the first one!

I bought her with a whole lot of miles so I figured there would be some work and I did my research before the purchase and found that if you take care of these cherokee's they can run for 300,000 miles or more!
That's definitely my goal-good luck!

I still believe in that inline 6...I hope the rest of the vehicle can keep up!

 

Have you checked the cap/rotor?
Where are you checking for spark, from the coil, or form the distributor? Remember to let it crank for at least 5 seconds when you check for spark, its a renix and has to see 300 RPM before it will spark.

Sounds like its the coil (you said it had voltage) or something timing related (CPS, SYNC Sensor). Are you getting fuel pressure now?

 

I could have been wrong about the range of ballast values - but if you replace a ballast, you should replace it with the same resistance (within, say, 10% or so. It's a wirewound resistor, and wirewounds are generally rather more accurate than carbons...)

A $3 multimeter? I'm not sure I'd want to use it for anything more than checking batteries. One thing I invariably advise is to spend at least a few bucks on a decent multimeter - say, $20-50. A good one will keep you going for years, and is worth the investment (most people don't need a high-end Fluke - but I was an electronics tech for a while. Most people have never even heard of a VTVM, but I have one of those in storage somewhere as well. Built it about thirty years ago, used it when servicing tube amps for bands and jukeboxes 'way back when.) Check around at Sears or your local hardware store - and get yourself something decent (preferably with leads that can be detached. If they can be detached, they can be changed and/or replaced, and that can come in handy. Only my "carry-around" multimeter has fixed leads, everything else has lead kits with croc clips, backprobe pins, piercers, telecom clips, ...)

If it's stamped "5" (and not ".5" - which is usually rendered as "0.5" anyhow,) then it should test out at five ohms on the lowest ohm scale on your meter (which is typically 0-200 ohms.) A sweep needle won't move much, a DMM will be easier to read. However, since you removed a 1.1 ohm piece, you should replace it with a 1.1 ohm piece - you may be losing too much current to the five-ohm part. Pretty much all automotive ballast resistors follow a standard format, either 1/2"x1/2"x3", ceramic, with two terminals; or 1/2"x1"x3", ceramic, with four terminals. The fact of getting two relatively widely-spaced readings also tells me that either the resistor is defective (check with a third DMM - preferably a good one - and discard the out-of-range result) or test both meters with known and verified resistances and discard the one that isn't within spec. For $3, my money's on a faulty meter...

Or, just replace the thing with a bit of 14AWG wire (as I may have mentioned earlier) and forget about it entirely. I find that to be the easier solution.

 

I bought the cap/rotor last summer but the spark isnt even getting there.
I've been disconnecting the wire from the coil and holding it close with the boot pulled back to see if I'm getting any spark and nothing.

I believe we've cranked for 5 seconds or more and I will leave it in the ON position for 5 seconds or more prior to cranking.

And yes! I do have fuel now! It sounds like from one of you guys earlier that the grounds I re-attached along with the negative battery cable were linked to the fuel pump.

Since I just changed out the CPS looks like I'll move on to the SYNC sensor and back to the coil.
Thanks again!

 

the SYNC sensor rarely goes bad. Theres a way to test it though, it should be somewhere in those files I sent you. I would be looking at the coil.

It doesnt matter how long the key is on, it has to crank for at least 5 seconds, or as long as it takes to reach 300 rpm.
In the Renix manual, look up "Crank Mode"

 

Yeah I thought $3 bucks was crazy but worth a shot, it does have detachable leads but I'll probably pick up a better one. My uncle's is pretty nice seems like it just needs to be recalibrated.

If you get a chance would you mind sending me a picture of what you did on your wife's 89' I think it was?
It'd really help to see what you did to replace the ballast with the 14 gauge wire so I can duplicate.

Thanks again!

 

Ok great will do. Have you ever seen this site? It might help some people out if its good info. The only thing I had a problem with was what he calls the resistor. It took a little while to find the part but from 5-90's advice sounds like I'm just gonna replace it with some wire anyway.

http://www.lunghd.com/Tech_Articles/...iagnostics.htm

(it's also great for me because of all the pictures!)

 

Do you know what any of the auto parts stores call the the quick connect fuel line fittings?

I searched and couldnt get any pics or prices or matches that seemed correct

 

yeah, thats a good site, and Im making up the splice right now, Illl post a pic

 

Hers that connector, Camera was screwing up so I had to have my girlfriend hold it. Both sides are supposed to be spade connectors, but I only had 1.

 

I attached a picture of what I'm talking about because the pdf wouldnt let me copy anything or maybe I just don't know how.
I'm referring to the right column.

I was wondering if the MAP sensor doesn't give the proper barometric pressure signal to the ECU would the computer tell the module not to send fire from the coil?

I think my manifold has a leak and never did get it apart last week.

I didnt think that would give me problems starting although I knew it would run poorly.

Could that keep her from starting?

 

Is that heat shrink around the connections?

Thanks for the pics it really helps!

 

yeah, its heat shrink... I dont think the MAP would keep it from starting.
Only things ignition related that would keep it from sparking are CPS, SYNC, COIL, (Bad ECU?)
Edit: Sync sensor wouldnt cause a no spark condition afaik, the ECU would just have to "guess" when to fire off of the CPS input. It would run, but not very good.