Hello folks!

New here and looking for some advice...

I just bought a '95 E-350 Cutaway Box Truck with the 5.8. 215k mi. It had an erratic miss when I picked it up. Sometimes it would run smooth and sometimes rough. I figured it was tune up stuff. It also had a tick that I could have sworn was a donut gasket.

Today I decided to see what I could do for it. I pulled the #8 plug and found that it's gap was set to about .025. The next 6 I pulled were in the acceptable range of .042-.046. I did not pull number 1 because I probably would have had to pull the front wheel and my jack was not at the house. All plugs I pulled looked good.

The wires also looked pretty good. I pulled the distributor cap and looked at it and the rotor button. Both looked okay, but I still sanded down the contacts on the inside of the cap. One thing I did notice is that the cap didn't sit real tight on the distributor. It was fairly easy to move out of place, even with the tabs clipped on.

After all that I cleaned the throttle body thoroughly with TB cleaner and a toothbrush. I must say I have never seen such a nasty throttle body in my life. I used the entire can on it which dissolved all kinds of sludge.

I took it down the road and to my surprise the tick that I thought was the donut gasket or an exhaust manifold gasket was gone. Apparently it was either arcing I was hearing or a lifter since it had been sitting for several weeks. It did run much better but still skipped under load. When I open it up I hear clicking sounds from under the cowl. I'm thinking I still have an arcing problem. Any advice?


Marc

 

change the plug wires, cap and rotor.

 

You're probably right.... Can't always see a bad wire. The do look like they have been replaced with the past couple years though. Maybe one has a burned spot. I didn't want to start spending money until I heard some ideas. Thought there might be another ignition related component that was known to go bad.

 

I always replace plugs, wires, cap and rotor, you can't see a faulty wire, and the cheap way they're made, they don't last due to heat breaking them down, years ago they were real wire, long lasting, but would throw a signal interfering with the radio and other electronics. The EGR is probably in need of replacement, if the TB was nasty, imagine it.

 

I would re-check firing order and Ignition Timing as well ...and if you have Vacuum advance on the distribiutor check line for cracks / connection too

 

A clicking can be an exhaust leak, get a vacuum cleaner tube or pipe, put your ear to one end, and probe around with the other while running, keep clear of moving parts BTW.

 

Ok, I will start with wires, cap and rotor. Got the job started but wow, that right side is something else. Would you recommend removing the plentum to service that side?

 

I believe friends have stated to me they get to it from inside, and some through either the fender or under, not sure how, but that's been their reply.

 

Alright... New wires, cap and rotor button... No change whatsoever. I verified firing order, it is correct. I drove it again and I now think the "clicking" I hear under heavy load might just be preignition... (Sounds different in a box van than in a car)

From a stop the truck seems to shudder and the engine seems to feel like it's bogging down, then suddenly it will catch up and away I go, strong and smooth. I'm beginning to think it is indeed a clogged EGR or something like that. How about an Idle air control valve or a throttle position sensor?... All pretty expensive parts to start guessing with, though...

 

The idle air control causes the vehicle to quit, not able to idle, doubt thats it, the TPS sometimes will cause a stutter, if the TB was dirty as you say, it could be damaged, I hate to have you replacing parts chasing problems tho. The TPS can be checked with a volt meter, I don't recall the voltage that you should read from it, it might be listed in a manual.

 

Well the shudder at takeoff is a classic EGR symptom, so I guess that's as good as any place to start. I don't have an OBD reader since my other cars are Cadillacs with built in OBD. But I know what you mean about the TPS... I had to replace one on my Eldorado a few weeks ago. I could probably score a TPS at Pull-a-part, but not sure a used EGR valve would be worth the effort. Do you suppose it would help if I just cleaned it out?

 

I got the TPS test:

Testing a Ford 5.0L throttle position sensor - YouTube

 

Thanks for the video. I will check the EGR and the TPS. Have a feeling it is going to be EGR though... Especially as dirty as the TB was. Literally chunks of crap came out when I cleaned it.

 

Think it's worth trying to clean out the EGR valve if it is indeed clogged?

 

Yeah, but flushing the TB likely washed trash toward the TPS as it's on the shaft.