Okay, after changing the throttle pedal assembly and getting my PS back on the road just in time for the big weekend and dragging my trailer over the coast range now it is running like it has a miss. It ran great through 3/4 of a tank of fuel but then drove it the other day and it runs rough. Anyone have any ideas. I'm thinking HPOP or injectors. I am going to change the oil and fuel filter tomarrow and see if it helps. It idles rough and runs rough driving down the highway. Power is low. Had to run it with O/D off all the way home and in 2nd gear over the mountain with no power. I don't know what they run like if an injector is bad so if anyone has any advice I could use it. I checked the VC plugs and they look good. Even tried unplugging one at a time and it made it run worse when one is unplugged.

1997F-350 what do you think buddy? You bailed me out with your wisdom a coouple of days ago. Any thoughts?

Thanks,
Mark

 

any check engine light before you unplugged the valve cover connectors (cause you certainly would have after)? even if you had one bad wiring harness it would run really bad if you unplugged one conector cause that one connector is for the all 4 cylinders on that side of the engine. did you pull the VC and look at the wiring?

 

No check engine light. I thought one connector was for two injectors and two glow plugs. Have not pulled the valve covers off yet.

 

you are correct i was in superduty mode when writing that reply. 4 connectors total 1 per 2 cylinders. even though there is no light you should get it scanned anyway cause i still may have codes in there that can help us.

 

Okay. Thanks. Not trying to correct you, I just ohmed out the injectors and glow plugs last night. That is why I thought it was two per plug. I'm going to change oil and filters today and see if anything changes. Only been about 3000 miles since last oil and filter change.

 

if i am wrong you SHOULD correct me!! what did you find when you ohmed out the injectors? i am assuming you checked from the high side tot he low side of the injector.

on the connector it would look like this _ _ _ _ _ 5 pin connector
1 2 3 4 5

1 and 5 are glow plugs pin 3 is the high side wire common to both of those injectors and 2 and 4 are the low side one per injector. to check ohms one lead form ohm meter to 3 and the other to 2 or 4 respectively. this test should show a max of 3 ohms if the under valve cover harnesses and the injector coils are good. glow plugs should be under 20 ohms.

does that line up with what you found?

 

Yes, that is what I did. They all ohmed out at 3.5 is that okay? The glowplugs all ohmed out at well under 20 ohms. I used a Fluke 337 True RMS clamp meter.

 

yeah that all sounds good. well good in that it rules them out not good in we still have a miss and we don't know why. try unplugging the ICP sensor. its one the driverside head in front under the plastic cover. its the one that your 10k mod is in. also pull the 10k mod out while we chase this. if it runs better you need an ICP sensor. note this will throw the check engine light on a store a code so try that after you get it checked for codes if you can.

also do the oil change in fuel filter as you planned maybe you will get lucky.

 

I have had the 10K unplugged since I replaced the pedal assembly. I just unplugged the ICP and it made no difference in how it ran. I'll run to town now and get oil and filters. I will let you know what happens after the oil, filter and fuel filter change.

Thanks for your help.

 

1 or 2 injectors would not affect it that bad. at least on my truck it didnt.

it would idle decent and run good above 2,000 rpms. anything lower and it would stumble upon acceleration.

do you have the vc's off?

what kind of fuel pressure do you have?

 

i'd be willing to meet you to hook it up to my laptop.

 

It idles a little rough but not like its going to die. It kind of acts like you describe. It runs pretty good above 2000 rpm but under that it acts like it is missing or not getting enough fuel.

No I don't have the VC off yet. I was going to change oil and filters before I pull those off. I was going to change oil today but they are paving the road in front of my house so I don't want to drive it through all the tar to get it around to the shop. I'll move it in the morning. Still have the travel trailer hooked to.

I'll let you know what happens and may take you up on meeting you and having you check it out.

Thanks!

 

i would bet that fuel pressure wouldn't be the probelem since its kind of opposite of how it would run if it had low pressure/volume. also since the injectors all ohmed out good you shouldn't need to pull the valve covers.

if you and 1997f-350 could meet up to check for codes, cylinder contribution test, and buzz test it would be very helpful in where to go next.

 

not trying to hijack this thread but what program do you run on your lap top, I am currently looking for something that will read Ford Dodge and Chevy both gas and diesel?

 

obd2.com EASE