It died on me at lunch

[sbolt19]

Headed home for lunch today, I was going up a hill and the bronco just died. It was like someone reached over and turned the key off. No warning, nothing, just died. It fired right back up, ran for a couple of seconds kind of rough, cleared it's throat & then would run for a little while longer then die again. Luckily, I work close to home so I was able to limp it home. When I was sitting at a light after it had already died a couple of times, it revved up to probably 1500 RPMs and died again. Did the same thing sitting at the stop sign on the bottom of my street.

Now, I haven't had a chance to look at it, as I had one of my guys pick me up and bring me back to the office, but it's a little concerning because in the 5+ years I've had EFI, it has never done something like this before. I'm not an EFI guru by any means, and so I'm gonna need some help. What I have is the system off of an 87 Merc. Grand Marquis, speed density unit. Where should I start and what should I start looking for?

[Viperwolf1]

Look at the fuel pressure. Check for codes.

[sbolt19]

Alright, I can hear the fuel pump and it doesn't sound any different from any other day. I'll have to check the pressure on the rails when I get home, so that isn't a big deal. The problem I do have is that I didn't install the EFI system, and I don't have a code reader. The EEC is pretty easy to pull out, but I've never had to check the codes or anything like that. Tips on what reader I should go get, or does someone here in the Springs have one and would they either let me borrow it or come over and read it for me?

[Gregg]

Does it have a Kenwood stereo?

[Gunnibronco]

I'm just about to install mine, here is the new EFI page w/info how to get codes from a bulb & jumper wire.

http://www.oldfuelinjection.com/?p=13

I think this is what you are looking for.

Chad

[Booger]

Check fuel filter also.

[sbolt19]

No but his brakes lights didn't work

You laugh, but I do have a gremlin that causes my driver tail light and passenger front turn signal light to work intermittently. I have traced those little bastards to no end and have not found a reason why they will work today and not tomorrow.

[sbolt19]

isn't fuel pressure at the rails supposed to be around 24-28? I ask because I am getting 34-36 right now.

Fuel filter is clear, all electrical connections are good & secure. I don't know what to think. I didn't do anything different than usual the other day. It ran just fine in the morning going into work, then started acting up going home for lunch. I can't think of anything different that has happened/I have done to cause it to act that way.

[Viperwolf1]

30-40 psi is right. Any luck on the codes?

[ZOSO]

How does it run after sitting a while?

[RJLougee]

Gary, if you haven't done anything to it lately, I would be looking at:

1. TFI module, this should throw a code.
2. Intermittent failure of the coil, this most likely will not throw codes.
3. Intermittent failure of a relay, depending on the relay, may or may not throw a code.

Mentioning the brake/signal light issue brings up a possible problem with grounds. 99% of the time, poor grounding causes the lights issue and bad grounds cause all kinds of issues with EFI systems. Personally, I run a 2 gauge neg batt cable to one of the starter bolts, with a 4 gauge cable linking the block to the frame and body. The little 10 gauge wire from the neg cable goes to the starter solenoid ground and I try to tie all the EFI grounds into this point. If I can't, I'll run another wire to a central point and run grounds to it.
HTH, Joe

[sbolt19]

I'll look at the grounds for the lights again Joe. It's been a while since I really looked hard for them. But I think I found my problem with the cut out...or I should say that Zack helped me find it. My ignition switch. We did the self test and it wasn't giving any codes & when Zack turned the key, he noticed a stumble in the fuel pump. Tried it again & same thing, so we figured that is what it was. I was backing it out of the garage & it died again on me, so I started it up and fiddled with the key and sure enough, it died again. So me thinks the ignition switch is so sloppy that it isn't making regular contact and it finally decided to call it a career. Now I gotta remember what year the Centech ignition is. I think that is off of an 87 F-150.

[Gunnibronco]

I have a new Centech harness with the included ignition switch, I wasn't planning on using it. I was going to use my stock Bronco switch. If you want my Centech ignition switch its yours for the price of USPS or UPS whatever.

Chad

[sbolt19]

Gunni, sorry I didn't get back to you yesterday, but I found one here in town. It happened to be the ONLY one left as a matter of fact. You might want to hang on to it as a just in case. For those of you who have a Centech harness, the ignition switch is out of a 1970 Jeep CJ-5.

On a side note, I finally found that thing about 4 pm yesterday afternoon, got over to my Bronco about 4:30 and managed to change that sucker out, drive 5 miles to the ice rink and still make my son's hockey practice at 5. The fastest I have ever changed out an ignition switch, granted they aren't hard, but when your fingers are about 3/4 frozen...

[Jesus_man]

Yeah, what a night to change that out!! Brrr!

J.D.