1989 4.0, auto, 4x4, 215k miles, k&n air filter,

all grounds freshened up last year. i installed extra ground cables from battery to radiator support and from intake to firewall.

issue:

engine turns over strong but won't fire off. as i start to turn the key off, it acts like it wants to start then blows blue smoke out air filter. it did this two weeks ago. i pulled the wires off fuel pump ballast resistor, cleaned them, reinstalled them and she fire right off. no such luck this time.

is this a cps issue? i have not checked it.

 

Check your spark plug wire order, how long has it been acting this way?

 

unless some kids popped my hood last night and crossed my wires, im pretty sure that's not it. :-)

it cranked and ran fine last night and for the last two weeks.

 

Check for correct fuel pressure and GOOD spark.

Could it be timing? If its backfiring....idk...seems odd...

 

Could be low fuel pressure. Try bypassing the resistor and see what happens.

 

I might just look inside the dizy cap. Idk, in Texas this time of year, but condensation in there can cause some grief. Cruisers CPS test is in my signature. If you have a meter I wouldn't hesitate myself. Just takes a minute to rule that one out.

Mine backfired when some of my wires to my lower sensors where grounding, the ones that come off the injector harness and run down to the knock, CTS, and 02 sensors.

Do you hear the pump run for a couple seconds when you turn on the key?

If my car didn't start I'd check for spark, then try starting fluid if it did have spark. Or maybe the other way around.

 

Fuel pump comes on with key. Didn't put gauge on it but fuel squirts out of the Schrader valve on the rail. There is no spark. Fresh tune about 6 months ago, less than 500 miles on the cap, rotor, etc. I did clean all inside cap, still no spark. Tried bypassing the resistor ballast, still no start.

 

Coil could be bad.

 

I'd do the CPS test cruiser explains in the link in my signature. If you don't have one, a $5 Harbor Freight DVM will suffice for the purpose. Really, to do much with a Renix jeep you will need some sort of meter. There is also a coil contact writeup there, but I'd start with the CPS, (and check it's plug).

 

CPS test is in order as is the preventative maintenance step outlined below:

Renix Jeep ICU/Coil contact refreshing
　
　
The contacts between the coil and the ICU on your Renix Jeep can become corroded and loose causing a complete or intermittent no-start condition. I recommend the following procedure as a maintenance precaution to insure this is eliminated as a possible cause now and in the future.
The coil is attached to the ICU by two T20 Torx bolts. Remove these two bolts and lift the coil up off the ICU. You will see 2 pins and 2 sets of contacts. Clean both the pins and springy contact pieces with a good electronics cleaner.
Squeeze the springy contacts closer together with some needlenose pliers. Apply some dielectric grease to the contacts and bolt the coil back on to the ICU.
While you’re right there unplug the connectors from the ICU and inspect the pins in the harness connector. Make sure the pins are not retracted into the connector. Spray out the connector and the receptacle of the ICU with the same good electronics cleaner you used earlier. Apply dielectric grease to the connectors and plug them back in.
I feel this procedure should be performed at least once in the lifetime of a Renix Jeep.
　
Revised 11-29-2011

 

Gonna cHeck coil & cps tonight. Couldn't happen at a better time. We closed on our house Thursday. No I got a dead heep in the wrong driveway!

 

Better get a tow strap. And i bet cps. Good luck

 

I had the same problem on my 89, fuel pressure was low do to the little piece of fuel line that is connected to the fuel pump in the tank had cracked.

 

Hey! Congrads on the house.

Only takes three minutes to check the CPS, and about 20 to change it...the second time!

 

Cps tests out .5vac. Coil seems to be okay. Back to the drawing board. :-(