Hey guys just joined the site, and I need some help. I have an 87 Bronco with a 302, it barely starts... i have to keep my foot in it to keep it running, its runnign super rich... smokes like crazy, and ,misses like crazy.. Originally I replaced the Fuel Pressure REgulator, as I heard this could be causing the problem... no change. So i bought a Fuel pressure gauge, and my pressure tests perfect. The only code I consistenly get is TPS low voltage, but I eventually unplugged all the sensors on the engine (MAP, O2, TPS, EGR) with out any change. Of course in this condition the truck is completely undrivable. I have talked to Ford, and there 1st suggestion was MAP sensor, I dont think they understood how rich the engine is running..... Any help, thoughts, ideas, would be greatly appreciated....

 

what is your fuel pressure at the rail? PULL Codes running both KOEO a KOER tests. whats your timing set at. might be a stuck injector? have you pulled the plugs? when was it tuned up last with new plugs,wires,cap/rotor?

 

What is your voltage at the tps?

 

Ok, I pulled 4 random plugs, all were black and sooty. And before this plugs, wires, cap, rotor were all new. Fuel Pressure at the rail is right at 40 psi i belive (been a little while, but i know it was right were it was supposed to be) . KOER test just gives a cylinder imbalance code, on what seems like random cylinders.. I'll have to check the voltage at the TPS, timing should be good, (was set at the shop to pass smog), but im wondering if i should yank the dist, check it... and restab it??

 

dont pull the dist, just check it with a timing light. should be 10* btdc with spout connector removed. Does the motor get fully warmed up? is the o2 sensor hooked up and how old is that part. has anything else been done prior to this problem

 

Ok, I'll try the timing tommorow before work (on my way out the door right now). O2 sensor was initially hooked up, and I have tried warming up the engine (to warm the O2 sensor) no change....

Nothing had been done to the engine prior to this... however it had been sitting for a couple of months waiting for new brakes... I took it on its test drive, was running ok, then it suddenly started missing.... brought it home... shut it off ... and when it restarted it runs like poo .... killing any low flying birds with all the fumes....

one other note... I didnt test my fuel pressure with the old regulator??? if i had bad injectors (at least 4 looking at plugs) would the fuel pressure still test good?

thank you for any input and help guys.... really appreciate it...

 

well if you tested fuel pressure with the engine running and it stayed steady after you shut the motor off then the injectors are fine. but if the pressure fell of after you turned the truck off then you might have a leaky injector. do you know what temp tstat is in there? it should be a 195* as well.

 

If by a couple months you mean close to three your fuel is starting to turn nasty!!
If there is not much in there I would pull most of it out and refill with fresh fuel and
of course some gas line dryer and some lucas fuel injector cleaner triple dosed.
I would also pull out the O2 sensor and heat it up with a torch for 15 seconds or so
until it gets all the build up crisped so you can wipe it off. OF course new plugs or at
least clean them all will help.