No Spark I think

Ask technical questions about your Ford Bronco II here. Technical write-ups on your axle swaps, engine swaps, chop tops, etc. are encouraged.
UndeadBronco
Posts: 24
Joined: Tue Mar 30, 2010 3:49 pm
Location: Oklahoma

No Spark I think

Postby UndeadBronco » Tue Mar 30, 2010 4:49 pm

A friend gave me his 87 Bronco II which would not start for him after coming out of Home Depot. I've had it for about 3 months and I still can't get it to start. I have done quite a bit to it but now I'm stumped.

At first I thought it was fuel related becauce when I depress the schrader valve on the fuel rail (just after having the key in the ON position) only a steady dribble would come out.

What I have done so far:
Spark plugs
distribuor cap & rotor
spark plug wires
oil change & filter
air filter
intank fuel pump replaced
side rail fuel pump replaced
checked for vacuum leaks & cleaned/replaced all lines that ran to the intake
fuel filter just under the engine compartment replaced
(I can't manage to get the canister fuel filter thats on the side rail off to replace the cartridge)
fuel pressure regulator
replaced the rollover switch under the passenger side dash
added a bottle of HEAT and injector cleaner
new battery & wires
checked all wires running to the solenoid on the passenger side fender & made sure it was working
undid, cleaned, and replaced all locatable grounds
new ignition coil
checked each relay on the passenger side fender with a known good one, replacing 1 at a time
removed and cleaned the EGR
removed and cleaned the TPS

At the moment it doesn't seem that its getting spark but I'm not sure why or how to test. I used the screwdriver stuck in the spark plug wire placed near ground method 3 seperate times and can not get a noticeable spark. There are 2 wires, a red and a green that go to the ignition coil and the red one has 12V with the key in the ON position but I'm not sure how else to test it. There appears to be a small ballast attached to the coil housing which runs to the red wire on the coil but I'm not sure how to test that either.Image
There are pictures of most everything mentioned at http://s149.photobucket.com/albums/s47/sadman_the/bronco/ and I can add any more if needed. I don't have a code reader unfortunatly.

broncofan
Posts: 65
Joined: Tue Aug 18, 2009 1:12 pm
Location: FT. Hood, TX.

Re: No Spark I think

Postby broncofan » Tue Mar 30, 2010 5:52 pm

does your bronco have the module on the back of the distributor? autozone can check it for you at no charge. Had to change mine twice since Ive owned my 84.

UndeadBronco
Posts: 24
Joined: Tue Mar 30, 2010 3:49 pm
Location: Oklahoma

Re: No Spark I think

Postby UndeadBronco » Tue Mar 30, 2010 7:24 pm

Yes, I think it does have a TFI module.
Image
Image
There are 6 wires going to this TFI which is mounted to the distributor somehow. I'm not sure where the wires run from there though. It looks like it is going to be rather difficult to get off since its about 1 1/2 inches away from the firewall. I found a test procedure at http://www.therangerstation.com/tech_li ... ostic.html under Test #5
Image
1 - Remove the TFI from the distributor or the front fender apron.
2 - Measure the resistance between the TFI terminals as shown below:
a. - GND-PIP IN: should be greater than 60 ohms.
b. - PIP PWR-PIP IN: should be less than 2,000 ohms.
c. - PIP PWR-TFI PWR: should be less than 200 ohms.
d. - GND-IGN GND: should be less than 2 ohms.
e. - PIP IN-PIP: should be less than 200 ohms.
3 - If any of these checks failed, replace the TFI with a new one.
Is there a way to test it or the part of it that runs to the ignition coil without removing it since its so difficult to get to?

UndeadBronco
Posts: 24
Joined: Tue Mar 30, 2010 3:49 pm
Location: Oklahoma

Re: No Spark I think

Postby UndeadBronco » Wed Mar 31, 2010 4:49 pm

Went and got a TFI module from O'Reilly's today. At $36.99 ($40.14 with tax) it was a bit more than the 29.99 others had mentioned that AutoZone sells it for but I figured I could just return it if tht turned out to not be the problem. As I fortold in my last post, yes, it was a bit tricky to get the old one off. I used a mirror to see back there and determine that the 2 bolts holding the TFI on were hex head bolts. Then just using feel I tried different sizes of sockets. I narrowed it down to either 7/32 SAE or 5.5mm socket. Unfortunatly though the bolts are set deep enough in the module that a normal socket is not long enough to get a bite on the bolt. So I had to go to my local hardware store and find a deep well socket of each type or a set containing both. You can't use an extension because the base of the socket where it connects to the 1/4" ratchet flares out thus a deep well socket is required. At Steve's wholesale tool I found a set of 8 metric and a set of 8 SAE for $3.46 each, so $7 for new sockets which included the ones I need seem a good deal. Browsing the asiles for an extra 2 hours I aslo found Image
for the sweet price of $3.57. I knew the socket sets would work but this tool might make it easier I figured so I got it also, along with other odd goodies I happened to find there. :D

The tool proved itself well worth $4 in my opinion as my TFI module came off in about 2 minutes. Heres the old TFI, looks as though it had been replaced before.
Image
So I can return the socket sets or just keep them since I've spent more than that on a drink at the bar before $7 on new tools is $ well spent.

Getting the new TFI on was a bit tricky and I had to use a few choice explatives to get it on there but it didn't take more than 15 minutes. Plugged the wire connector in, dropped my tools into the tool box, cursed the idiot that designed it so you couldn't get at it one more time then turned the key. The ol Bronco didn't even have to crank really it just fired up instantly. No sputtering or anything even after sitting for 3 + months. :beer: I cleared off all the stuff around it, oil catch pan, new side window which I need to put in, and took it for a ride straight to the car wash to clean off all the caked on oil under the engine. See before I got it 2 other people I know had owned it besides the original owner. Before it was given to the second owner it was in emaculate shape and looked absolutly perfect in every way inside and out. The 2 owners before me had had it for just over a year and have totally ragged it out and beat the hell out of it. :puke: I've got everything to fix it up or have already put it on except the passenger door lock solenoid, a new windshield, a new hood, and a spare tire.

But anyways, it was teh TFI, and it works great now, I just got to find the oil leaks and replace some parts that the previous owners damaged and it'll be in pretty good shape. I do have 1 other question though. When I had it running, before I took off to the car wash I noticed that the Gray wire withthe blue connector on the solenoid in this picture gets extreemly hot and stays that way just sitting at idle.
Image
Hot enough that you don't want to touch it again. :eek: Is that normal? If not is there a fix?

KRE
Posts: 30
Joined: Sat Nov 15, 2008 5:09 am

Re: No Spark I think

Postby KRE » Thu Apr 01, 2010 5:38 am

Sorry I did not your post before now, as I would have suggested, not replacing the TFI w/o also replacing the Dist Trigger. Pulling the Dist. is required to do this operation, but well worth it in the long run, as any minor issue with the trigger becomes a major issue to the TFI.

Glad you have it running, hope you enjoy it.

broncofan
Posts: 65
Joined: Tue Aug 18, 2009 1:12 pm
Location: FT. Hood, TX.

Re: No Spark I think

Postby broncofan » Sat Apr 03, 2010 4:45 am

Glad you got her running again. Sorry about the tfi tool, i should have told you a allen wrench works just as well. As far as the wire just trace it and see where its from. my 84 doesnt have it. if you dont need it unhook it and mark it.

UndeadBronco
Posts: 24
Joined: Tue Mar 30, 2010 3:49 pm
Location: Oklahoma

Re: No Spark I think

Postby UndeadBronco » Thu Apr 08, 2010 1:28 pm

Yes, it runs great now. So great infact that my girlfriend decided to stop driving her Taurus I got her and drive teh Bronco instead because its so fun. :rolleyes2: So I can only work on the Bronco when shes not going places now. :frown:

I don't really want to pull the distributor as I know what a job that is but if it breaks again I will deffinatly have a look at teh distributor trigger.

You don't have a gray wire to the solenoid? :wtf: Well I'm sure I can get in enough time to trace the wire down, I'll post back when I figure it out.

Another problem I noticed is that the fuel gauge reads empty at all times and the little "need fuel" light on the center console is always on. I have heard that this Bronco often has fuel gauge related problems that is why I decided to replace the fuel pump inside the gas tank right off the bat. Hopeing it would solve the no run problem and fuel gauge problem at one go but it didn't. Is there anything else I should check to get the gauge to work before pulling teh insturment cluster? Maybe some sort of switch or relay somewhere? I didn't replace the sender switch inside teh tank by the way, I just cleaned it very throughly and carefully and then made sure I could get an ohm reading off it before putting it back in. It appeared to be a very simple resistance switch and cleaned off pretty well, also saved me about $110 off the price of buying the whole fuel pump assembly. Is it likely that that switch is really bad even though I could get readings off it from a standard volt meter before reinstalling it?


Return to “Bronco Tech”

Who is online

Users browsing this forum: istellabot [Bot] and 2 guests