89 Eliminator Renix Need Help Please!

[one2hunt]

Ok fellas, the ol girl has thrown me a curve again and I need help. My mechanic just diagnosed it as a TPS and it didn't fix it. I drive 5 1/2 hrs to my new job every 14 days and then 60 per dayround trip to and from the oil rig. My 4.0 MJ started breaking up bad to the rig last trip. Losing power-the more I tried to excellerate the more power I seemed to lose. It got to the point where I couldn't get above 5mph on an incline. I changed the fuel filter. Blew out the vacuum lines with carb cleaner, ran gas treatment through the tank-4 tanks now-all 94 octane. It got slightly better and I was able to sustain 55-65 mph for most of the 5 1/2 hr trip home-actually now closer to 7 hrs. I love the ol girl and really don't want to let her go. I have 4 days til I head back. Any advice would be greatly appreciated.

[cruiser54]

CRUISER’S VACUUM TEST FOR EXHAUST RESTRICTION

Your vacuum gauge should come with an instruction booklet outlining the procedure. Hook the vacuum gauge up to a source on the intake manifold. Start the engine and note the vacuum reading. Usually 17 to 21 inches of vacuum. Throttle the engine up to 2,000 to 2,500 RPM for 20 seconds or so and the vacuum reading should stabilize to the same reading you got at idle. Let the throttle snap shut. The vacuum reading should shoot up about 5 inches of vacuum higher for a second and then come quickly down to the original reading. If the vacuum reading stays high and comes down slowly with jerky needle movements, you have an exhaust restriction.

Clogged catalytic converter?

[one2hunt]

Is the output at the tailpipe a reliable indicator? I can redline it in neutral. I just removed and blew out the IAC with throttle body cleaner. As of now my mechanic has replaced the TPS to the tune of $235. I shopped the part and am not happy but he's done right by me before so I'll take the hit this time. He won't take my money because it's not fixed but bottom line is in 2 days I have to report to work 5 1/2 hrs away and my truck is my ONLY source of transportation. If I can't make it to work then I don't have a job. I'm trying to avoid the easter egg hunt approach-as in replacing 55+ dollar parts one at a time hoping to eliminate the problem. I thought it could be the catalytic converter too but 3 people so far said no. Should I just remove it and replace it before my next inspection to see? I can't weld good enough to do the job so it will be more money out of pocket on a fishing expedition.

[fiatslug87]

Also check the EGR System

[cruiser54]

Kinda hokey, but have someone rev it up and see if you get a throaty sound out the pipe or if it sounds kinda like a vacuum cleaner.

[one2hunt]

Removed and checked the 02 censor. Disconnecte and reconnected the CPS. I run a business aside from working on an oil rig so time spent on my ride is money lost. I lost daylight and gotta load the truck for work tomorrow so the best I can do is pray that my mechanic knows how to use a tester and check everything without me having to replace 1k worth of parts only to end up selling my truck(that still doesn't run right) for scrap price. Thanks guys-but I think I'm screwed. I've lived here for 10 yrs and canot seem to find a good mechanic-one that can acrually diagnose a problem without just changing parts until the problem is alieved.>Chris

[JFAComanche6]

Check the knock sensor and maybe even the MAP sensor. I hear the knock sensors either break or go bad kinda often, and I believe the map sensor has something to do with engine load pressure. And check the coil too, if acceleration seems to be a problem.

[cruiser54]

Knock sensor will NEVER cause a driveability issue.

 

They rarely fail and usually only need replacing because the wires got pulled out or they got smashed by someting.

 

A failed MAP sensor will cause extremely rich running.