[The Blue Behemoth]

My 89 Bronc was runnin fine, just a little loud (what'd you say???). I narrowed it down to the upper intake gasket and replaced it and I'm almost positive I put all the vaccuum hoses in the right place.
Now when I start her up she runs so quiet :hump . . . for about two minutes (or to the stop sign at the end of the block, which ever comes first), and then dies :shrug .
I haven't checked the codes yet cuz everything was working fine before. I'm wondering if anybody has encountered similar problems and could maybe offer a little insight into what went wrong or what I forgot.
Thanks,
Matt

 

[gearrat]

ok first off welcome to FSB :beer and before the guys cut loose on ya do a search or even look in the general repair and tech section i know that myself and crazed have had similair probs with our bronos.. nand once again welcome

 

[Steve83]

Always pull the codes first - it only takes a couple of minutes with a paperclip and might tell you exactly what you need to know.

 

[The Blue Behemoth]

OK, so i checked codes today and came up with 67 (neutral pressure switch open). Now to my knowledge this shouldn't cause the engine to stall. It has been causeing me to start the engine by jumping the solenoid to the positive battery terminal, but thats a whole other can of worms.

Unlike most similar problems I've seen posted, the engine starts right back up after it stalls. If I step on the the accelerator it'll keep running and then die once I let off after a few spikes. Should I check the resistance on the sensors even though I got no codes relating to them? If so which ones are most likely the culprit?

Thanks for the help and support guys.

 

[Tomh971]

dumb question... could this be a TPS problem?? ( doesn't know Broncos well enough to know if they even have one) but, that's exactly what the Mustang did when I out the intake back on after sending it up to Irwin PA to have it extrude honed. got to messing around and discovered the TPS didn't seat all the way, pushed it on till it "snapped" into place... and that was it... < shrug > Fireguy???

 

[None2Slow]

You may also have a weak fuel pump. It will build pressure and as you drive, it just doesnt have enough to keep it up and stalls out. You turn the key back on adn it will pressure back up and start and repeat itself. What if you rev the engine up in park, does it still die? If so, put a fuel pressure gauge on it and see what it does. It should be about 39 psi at idle. Not sure if it goes up, but if it falls, then you have a fuel delivery problem. Could be the pump, regulator or maybe injectors. But also check the TPS setting.

 

[The Blue Behemoth]

I've been playing with my vaccuum lines and have discovered that when I pull the line going to the vaccuum tree on the top of my intake everything runs fine. When I put it back in it dies. The other hose in this port runs to the back of the engine and I cant see where its going. The third port has a little a little nipple capping it off and there is always oil in it when I pull it off.

I hope I uploaded the pic correctly, if so this port is mounted to the firewall right behind the intake. Any insight in the matter would be greatly appreciated, and Merry Christmas y'all :santa .

 

[Steve83]

What transmission do you have?

The oil in the vacuum line is BAAAAAAAD! Are you sure it's oil and not gasoline? Is it transmission fluid?

If you have a manual transmission, use the Haynes manual procedures to test the MAP sensor (just left of that picture), EVR, and TPS.

You have a vacuum map on the core support, air filter, or hood, so use it to confirm that your vac lines are routed correctly. If it's missing, check the Diagrams photo album in my signature link.

 

[The Blue Behemoth]

The tranny is an automatic C6. If the fluid in the lines isn't oil its transmission fluid. I couldn't make out the diagrams on your link so I'll be checking for a map under the hood first thing in the morning.
Thanks for the help.