i have a 1989 jeep wagoneer limited xj 4.0 auto i can go outside in the morning and it will start up good but after you shut it off once or twice it wont start back up unless you let it set at least a couple hours i put a new cps on it today and the coil and icm arent very old either me and my dad checked the spark and its firing strong but its orange not blue and it seems to have good fuel pressure i really need some help ive been trying to fix this for almost 2 weeks also somebody has removed the ballast resistor and just spliced the wires together

 

Take a look at Cruisers stuff in the link in my signature. Starting with cleaning up the grounds is always smart.

AC voltage CPS test; Small clips on the meter leads really helps.

Unplug the connector at the back of the manifold with wires going down to the bell-housing/cps.
Probe the two wires to the cps with the meter set on AC volts. (a 200 scale on mine).
Crank the engine and note the voltage. (jump it if your battery is low)

Mine somehow works with only .3 my wiring/grounds must be pretty spiffy. .5 seems to be a good mark. One article talked of .5 to .8. **Update, it soon failed. I installed Napa #css980 in my 90.**


The MAP tube is not causing an orange spark, but a common problem that is supper easy to check. :


There is a brittle little tube. It comes out of a rubber plug, low on the engine side of the throttle body. It runs back to the firewall, then up to your MAP sensor sort of high up there near center on the firewall. CRUCIAL!! The MAP will tell the ECU to dump fuel with less/no vacuum. Any crack or blockage and it will be pig-rich. (black smoke, fouled black plugs).

 

Before throwing more parts at it, click on the link in my signature and do posts #1, 3, and 4.

 

i checked the map tube and i didnt see anything wrong with it and it wasnt blocked because i blew through it but where it goes into the throttle body there are 2 holes it it in the bottom hole is that right and i have already cleaned all the grounds and even added an extra one from the firewall to the intake the coil and icu are both brand new but i will pull the coil off tommorow and check the connections

 

when i get it started it will start right back up as long as i dont wait more than 10-15 seconds to start it back up

 

Fuel pressure/delivery

 

is there any way to test it besides a furl pressure guage because i dont have one

 

Not accurately,

 

Once I set a timer, went out my door to my jeep in the driveway, opened the hood, checked the CPS. Plugged it back, closed the hood and came back in, 90 seconds.

Not too tough to rule that trickster out in my opinion.

 

ok ill try to borrow a fuel pressure guage and a multimeter and check the fuel pressure and cps

 

The $5 Cheap-O-Meter from Harbor Freight actually works OK. For a while anyway. Besides the AC test for the CPS, you can check voltage and resistance. I've had, (and have) a number of them. The display goes out, the leads brake. You can't get ANY water on it. Still for 3 to $5, a pretty handy thing.

 

ill probably just pick one up at walmart tommorow they have them for 15 bucks

 

On a Renix a volt,ohm meter is a must have!

 

Make sure it's digital. The analogue, (with a needle), have there place, but not here.


X2, there^. Without the rare DRB II scanner, or an Snap-On 2500 we are "in the dark" without a digital meter.

 

Now that we have an autozone here it's free to borrow a fuel pressure tester. You need to buy it, but get a full refund on return. (ask them)

If it doesn't spurt fuel out of the schrader valve on the fuel rail into the rag you are holding there when you press that dealie, the gauge is not going to read correct pressure.