[afmiller80]

I have a '88 FSB 351W FI. I am having a problem with my bronco when I am driving starting to sputter. It doesn't do it (so far) when I am not in drive or going down the road. I will be going and it will just start sputtering like it is dieing out and then it will just go back to normal. It doesn't happen all the time and it seems to happen more when I have driven for a while (15-30 mins). It will jump around 500-2000rpm and sometimes I can tell by the immediate slowdown but other times I just see the tach start jumping around up and down? I am confused and would like some ideas of where to start looking. Here is my list.

1. Fuel filter (replaced 6K mi ago)
2. Inline fuel pump.
3. something electrical???
4. Rear axle has been leaking oil so I will make sure it is full.
5. Transmission? (Has a new transmission with only 32,000 mi on it,)

Any help or advice of where to start wrenching on would be appreciated.

 

[SigEpBlue]

Pull codes.

 

[Gacknar]

Check for codes
http://fordfuelinjection.com/?p=13

 

[afmiller80]

Codes ran

Ran codes got
67-neutral saftey circuit failure.
33- EGR valve opening not detected.

Now I may be dumb but it doesn't seem like either one of these things would cause a problem while running down the road that would cause the truck to sputter like it is. If I am wrong let me know.

 

[SigEpBlue]

No, you're correct. Neither of those should cause a loss of engine power like that. The most unfortunate part is that it'll do it for a little bit and then completely go away, making diagnosis a pain in the arse, as you've found out.

The immediate things to check that come to my mind (assuming this is only engine problems and the transmission is fine) are ignition module & coil, fuel system (pump, regulator, & filter), and bad grounds.

The other thing possibly related to your codes is a cruddy EGR system (valve, vacuum lines, EVP sensor, or regulator). The EEC is probably trying like hell to open it, but since it's sticking OR your EVP sensor is shot, it takes a lot to overcome. Then, if and when it finally DOES pop open, the engine's dying...or at least that's my theory. It's a place to start, right?

After the EGR is in operating condition, you can start going down the line with ignition and fuel system diagnostics. Usually with one of those systems however, it's a constant condition.

 

[afmiller80]

Thanks for the suggestion. I guess I will continue to trouble shoot and hopefully find something. If not something will just break and then I will be able to figure it out that way! Thanks again for the help.

 

[imlikeojnow]

check all your vaccuum lines, cannister (coffee can) make sure it aint rusted. make sure egr tube is in tact. also check your injectors.