85 XJ with a 302 won't start...

I have a 1985 XJ that has a FORD EFI 302 in it. I have narrowed (I believe) my problem to be now chassis related and not 302 related.

The vehicle freely cranks over and will continue to crank.

No spark at the FORD coil. Coil also is within spec's. It is not getting voltage. I have checked and had tested the FORD TFI ignition module and it is good according to the test unit.

The Jeep is new to me and the 302 was already transplanted I did not do any of the work...which is a bummer.

My question is this: Can the ignition switch on the lower column allow the starter to turn yet not give the ignition switch to the coil? And what is this about an Ignition Relay by the battery that I have read about while searching?

The rig ran when I parked it a couple of weeks ago. I then cleaned the Idle Air Motor on the intake and coincidently I am now not getting any voltage to the coil...

THoughts?

Anybody...Bueller...

I thank you...

Cranking with no start + no voltage to the coil = bad crank position sensor. Check the resistance from the CPS and see if it's properly plugged into the wiring harness.

There is no cps on the 5.0, I am sure the good doctor was thinking 4.0 When my tfi went I had full crank and gas but no spark and power to the coil. I would go from the coil wire (12volt) back and trace to where you have power most likely its a loose wire. Making sure you have a good engine ground is always good also. Heck I would run a 12 volt wire to the coil just to start it and start eliminating variables.

Thanks guys....

I am going to try the direct hot wire to the coil this afternoon. I am also going to be picking up a TFI anyway...even though mine "tested" good and I was standing there while he was pushing the buttons. I have been told that they are still suspect?

I must admit that for XJ's this site has a looooooooot of information...

I'd be intrested in info on your xj. BTW which 302 is it? THere are 2 differnet maybe 3 FI 302's that I know of.

Ghost said:

I'd be intrested in info on your xj. BTW which 302 is it? THere are 2 differnet maybe 3 FI 302's that I know of.

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I guess that would have helped...

It is an 86' EFI 302 from a Bronco. It has an NP435 connected to the BW1345 or 1356...haven't really worried about which exact T-case...

It basically is a ford with an XJ chassis. Bronco 9" from same donor rig in the rear...carrying 4.56's and a full Detroit.

Front is a 78/79 F150 HP44 with 4.56's and is welded...(will change that someday)

It has the extended length Ford radius arm and lift kit from the Bronco...with a hybrid slide plate/wristed arm on the passenger side to allow excessive articulation.

The rear has drop shackles to match the amount of flex on the front....

Ohhhhhh....and the previous owner did not get around to re-inforcing the Uni...so that is paramount...

HarvesterofSorrow said:

I guess that would have helped...

It is an 86' EFI 302 from a Bronco. It has an NP435 connected to the BW1345 or 1356...haven't really worried about which exact T-case...

It basically is a ford with an XJ chassis. Bronco 9" from same donor rig in the rear...carrying 4.56's and a full Detroit.

Front is a 78/79 F150 HP44 with 4.56's and is welded...(will change that someday)

It has the extended length Ford radius arm and lift kit from the Bronco...with a hybrid slide plate/wristed arm on the passenger side to allow excessive articulation.

The rear has drop shackles to match the amount of flex on the front....

Ohhhhhh....and the previous owner did not get around to re-inforcing the Uni...so that is paramount...

Click to expand...

Ok, that is intresting. I have a 86 Tbird 302 and AOD in my shop awaiting 9", D44 and Tcase to go in a 84 that is also sitting in there. If you can I'd love pictures. [email protected]

There should be two relays, one is a relay for ignition, and the other is a main power relay. It's kind of a wierd set up but if either is not working, it wont start.


Dan

Sweet I will look into the ignition relay...I am going to be having a go at all these suggestions this afternoon...

Well...My head should be bleeding from all the scratching that I am doing to it...

I have checked fused links that are still present. Checked what I believe to be the Ignition Relay...still no coil voltage.

So I am going to be replacing the FORD TFI Module like many have recommended. Even though it "tested" good it is not to be trusted. I do agree that parts store testing is suspect at best. As I have had alternators or starters work at the store...but not for me...

I will buy a new TFI and if it fires up then I owe some muffins to a neighbor...wish I could ship you all some..

Perhaps try posting you query at a Ford site??

Rev

Rev Den said:

Perhaps try posting you query at a Ford site??

Rev

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Thanks...I already have on Pirate. They suggested that I replace the TFI regardless of what it tested.

Seems that it is or can be a very troublesome component.

By the way...I like your chop top. That is the profile that I might cut mine to...when it is time of course.

Gary E said:

There is no cps on the 5.0, I am sure the good doctor was thinking 4.0 When my tfi went I had full crank and gas but no spark and power to the coil. I would go from the coil wire (12volt) back and trace to where you have power most likely its a loose wire. Making sure you have a good engine ground is always good also. Heck I would run a 12 volt wire to the coil just to start it and start eliminating variables.

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I wasn't just thinking 4.0 Gary. If the 302 doesn't have a CPS, how does the PCM synchronize the spark with TDC?
Since the coil isn't getting any power, other possibilities than the CPS could be the PCM itself or the ignition module.

Jeeps don't like ford or chibby engines in their bays. :skull1: If you leave the jeep alone for any length of time it will likely spit that crap out of there. uke: FORD 302

Greddy

Dr. Dyno said:

I wasn't just thinking 4.0 Gary. If the 302 doesn't have a CPS, how does the PCM synchronize the spark with TDC?
Since the coil isn't getting any power, other possibilities than the CPS could be the PCM itself or the ignition module.

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The 302 is a more basic system. The dist is not "fixed" and therefore either is the TDC. You set the dist by finding TDC then stabbing the dist so the rotor is on the #1 contact on the cap. Then adjust from there by twisting the dist one way to retard timing or the other to advance.

Any luck getting it started??

It Is Runnnnnniiingggg

Well yesterday I picked up a new TFI cleaned the surface plates applied lube...and installed the new unit. Did a triple check of all the wires that I had been f*cking with and tried to fire it up...

STILL NO FIRE No spark at the coil...

Soooooo I debated burning the fucking thing and calling my insurance agent...while standing there I recalled how someone mentioned that they had a shorted TACH wire against the ignition wire and their XJ wouldn't run...

Upon further testing I removed all the non essential toys from the wiring and found that the tach power wire was on the same spade connector as the resistor wire for the ignition unit. The TACH in this thing was a piece of sh*t to begin with...

...Since the Tach took a sh*t, it was basically changing the OHM's on the resistor wire...Not allowing enough or whatever to the ignition. I unplugged the Tach power wire and I instantly had 11'ish volts with keyed ignition...

Tach is going to get tossed as far I can huck that f*cker....and then I just need to set the timing...

Thanks for everyones suggestions and thoughts...I have learned a hell of a lot about my XJ just from this thread and SEARCHING.

Re: It Is Runnnnnniiingggg

HarvesterofSorrow said:

I recalled how someone mentioned that they had a shorted TACH wire against the ignition wire and their XJ wouldn't run...

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it was an MJ

blew the damn fuselink EVERY TIME I tried to start it!