1998 Ford E-350 Van Smog / Shudder issues

[Catwoman]

Hi - I'm new to CNG and hope this forum can help me. My auction bargain van did not pass smog. I learned it was missing so spent the time to change the spark plugs, O2 sensors, and drive belt while I was at it since I can't afford to pay someone to do it. Boy, did I learn something about van spark plug removal... The van has about 130,000 miles.

Problem 1: After reading the forum info. on fuel injector flushes and Coalescent/filter assemblies I promptly bought the filter and flush supplies and learned there is an electric tank shut-off valve in my 1998 Ford E-350. I disconnected the 'crash shut off' wires as instructed and after running the vehicle, starting and restarting for 20 minutes, it never seemed to run out of fuel in the lines. Am I missing something here? I've seen the big nut on the main tank (won't touch it! - two axillary tanks in the rear) referred to on this forum and have not found any manual valves on the system.

Problem 2: New spark plugs and O2 sensors installed - now when I drive it the van shudders between 35 and 45 MPH (Third gear - tested on hill - it is an automatic) but operates fine at every other speed/gear. I may be asking for guesses on this one but I'm hoping someone has had a similar experience. Is this transmission sensor issue, Fuel Injectors (not flushed yet), Catalytic Converters plugged (fearfull - there are three), or does the compuvalve (just read the thread) have something to do with it?

A little frustrated but not giving up... Can you offer any solutions/suggestions?

Thanks,

Catwoman
California

[cowboy]

Re: 1998 Ford E-350 Van Smog / Shudder issues

if it ran good before you worked on it I would assume it is something you did first check the firing order make sure you did not cross any wires did you tell the parts house that it was cng powered may take different plugs or gap you may also ruined a plug wire pulling the off if they are old try a new set dont forget to get dielectic grease if I had to guess from 2000 miles away oh thats what Im doing LOL I would try the plug wires as at a 130000 thousand miles it probley has never had a set and remember KISS (keep it simple stupid ) check the stupid first as it can save a lot of money good luck and welcome cowboy

[cowboy]

Re: 1998 Ford E-350 Van Smog / Shudder issues

I have thought about your gas shut off problem it may be that who ever installed the aux tanks did not plumb it properley I am not up on how ford plums there system but you should have someone look at this as if you are involved in a crash you want the gas to shut off just like the fuel pump in a gasoline system are there any valves on the aux tanks if so try closing them than unhook power from cng solinoid ( at crash switch???) I dont know if this is the proper way or not how about one of you ford guys speaking up on this you do want to get the gas shut off for crashs fixed good luck cowboy

[Catwoman]

Re: 1998 Ford E-350 Van Smog / Shudder issues

Thank you Cowboy. I found one of the coils was causing the problem and replaced it. It still did not pass smog but it is far better than before and leads me to the mechanical aspects next. I have contacted a local dealer who will hopefully help me with the tank shut off issue which I think may be the most costly of the fixes. Thank you so much for your advice. Stress level has decreased.

Catwoman