2.9 start issue. sorry long winded

[fogmikey]

Hi, long-time lurker, first time poster. 88 Ranger 2wd long bed, 2.9 auto, 210k, of which I'm responsible for the last 70k or so. Original motor developed a casatrophic coolant leak and has been replaced with serviceable used motor, alleged to be about 95k. No real issues when we put the motor in, and it fired right away and runs smooth, makes good power. Had a few issues with a bad TPS sensor and a faulty T-Stat from the parts joint, but it really was running good for about 4 days. Now alla sudden it cranks but won't even attempt to stumble. Pretty sure I'm getting fuel but haven't checked pressure. I am NOT getting spark that I can determine. Got 12v into the coil, and 4 ohms res in the primary, and 79k ohms on the secondary. Checked it against a new coil at the store, and it's the same. Question: If I have a failure in the distributor circuit, will the coil fail to show spark to ground? Going to make sure the distributor is turning, and probably ck the TFI module next. T/S vehicle out in the cold sucks, any ideas appreciated.

 

[fogmikey]

Re:

I should add that the only codes I'm getting are 21 & 24 which I believe is to be expected on a dead cold engine, static, correct? Either way, I replaced both sensors, but faults remain.

 

[Millster]

Yep, yep and more yep!
First thing I would try is making sure you ARE getting fuel. You don't need a pressure gauge, just turn the key to on long enough to let the pumps prime and depress the valve on the fuel rail. If fuel spurts out, you're getting fuel to the rail.
My next suspect would be the TFI. When my truck did the same (ran great up until it just died) it was the TFI. I let it sit too long before figuring that out and now it's all kinds of knackered but the TFI was the initial problem. I forget where I found them now, but a Google search turned up the resistance specs across the pins on the TFI (you'll have to take the module out to test it). I had several that were well out of spec and the replacement module took care of it. Put it in and it started up like it had never died.

 

[fogmikey]

Re: again

Yeah, that's where I'm headed next. Thx, I'll get back with an update.

 

[cavedweller]

My next suspect would be the TFI. When my truck did the same (ran great up until it just died) it was the TFI. I let it sit too long before figuring that out and now it's all kinds of knackered but the TFI was the initial problem. I forget where I found them now....NAPA seems to be the best source for the TFI ,at least for me....

 

[Millster]

Cavedweller:
Mate, you might want to go back to read my post again. I know all too well where to purchase the TFI modules, I was referring to locating the resistance specs on the Web so one can test their own module without having to take it to the parts store to have it tested. Though that's a fine option as well, if you're so inclined.

Anyway, no harm just wanted to clear that up.
Cheers!

 

[cavedweller]

Apologies ,jungling a lot of stuff with regards to this time of year....BTW best wishes,and seasons greetings to all

 

[sjr53]

About a month ago, my BII died on the road. I found the wiring connector had come partially unplugged from the TFI because the locking tab is broken. Fortunately, I figured it out in just a few minutes and drove it home. Alot longer ago, I had trouble with occasional no spark that I solved by replacing the whole distributor with a rebuilt including the TFI. I've also had corrosion on the low voltage wiring connector at the coil because of unfilled holes in the inner fender (splash gaurd) that was getting the coil wet. I filled all the holes with bolts.