If I keep it running at 1500 rpm it starts bogging and losing rpm and will clear up for a few seconds then starts bogging and losing rpms again.

 

Unplug the mass airflow sensor and start it up with it unplugged . Post results / please

 

I'm not going to bother, I just received word that it just spun a bearing. Don't know what I'm going to do now.

 

The oil was thinned out and it now has a bottom end rattle. I unhooked the maf which isn't too old and it idles and I notice the o2 sensors are switching which they don't really with the maf plugged in. I guess I'm going to put acl cold air intake on it with a new sensor and 3 o2 sensors. Need the cold air intake because of the crappy leaky air box these things have. At one tine it was sucking unmetered air from the box.

 

Sounds like a waste to me. The stock intake is excellent, so replacing it with a crappy aftermarket intake on a motor that needs serious addressing is a bad idea. Aftermarket CAI will make many vehicles that run perfectly well with stock parts run like crap.

Sounds like you have a bad MAF. Thats kind of a side note if you have serious engine damage however. Your only option at this point is either replace engine or rebuild it. You can't work around this or ignore it.

I seriously doubt that the oil thinned out and caused damage. Low oil pressure when the oil warms up often means the main bearings are so trashed that when the oil heats up and gets thinner, it leaks past the mains too rapidly, starving the rod bearings of oil. The main bearings have passages in them and oil travels from the block, through the main, and then through passages inside the crank over to the rod bearings. If you get too much clearance between the main bearings and the crank, the oil leaks out and then there is insufficient flow to the rod bearings, which are more sensitive to oil pressure and flow issues since they undergo a lot more stress than the main bearings do. Once the rod bearings get damaged its a matter of time.

If you act soon enough you can spare the crank from any damage, wait too long the crank will get scarred, or worse, if you throw a rod, the block might get trashed.

 

Trust me, the oil was thin as water. My gf doesn't maintain her stuff. I've also replaced tons of the stock air filter housings because of the air leaks out past the maf and out of the grommet where the wires go into it. I had to silicone the maf in the box on both sides of the sensor and then seal up the wires with silicone also. I wish I had a choice but we need a vehicle so it's gotta be driven. No way around that. If it goes, it goes. I used to drive a van for work that rattled a whole lot worse and did so for years so I'm hoping for the same results.

 

I went outside and plugged the maf back in and drive it and it's now running perfect. No bogging, no missing or fuel smell. I wonder if the plug was just not making good contact on one of wires.

 

Yup I've seen that many times , sometimes works for o2 sensors , unplug then plug back in

 

For a cheap scantool that seems two work with early Ford OBDII, an ELM with a 327 IC and free software FORscan seems to do the job. See this post for more info.

An example of a live data screenshot of my bad new MAF on my '97 Aerostar with 4.0l:



You can obtain an ELM OBDII adapter for well under $50 and the software is free.

 

I just dropped 3500 on a snapon solus last week and it does the job then some.

 

Oooookaaaaay.

I loved our MT2500 (the now-antique predecessor of the Solus, I think), but for home use the cost is a bit prohibitive.

For those who read this thread because they're Googling for "1997 Ford -100% fuel trim" or something like that, I thought I'd provide the info for an inexpensive (if not feature-rich) way for early Ford OBDII data mining.

But, sure, a professional tool will do the job too

 

I'm a diesel road fleet tech and do it on the side too. Otherwise I wouldn't have gotten it.

 

Ok it's time to burn this thing down. 4 more codes came up. Tell me if I'm wrong but since the egr diaphram is leaking a little, this is causing the po401 code since it can't open and the po174 & 171 codes came back from the egr diaphram leak as well. I now have a po420 that I believe to be from the car getting hot. Time to cut that off and put an o2 simulator on it.

 

Somehow I don't think thats gonna be helpful. Its impossible to tell if the cat is working properly when you have ongoing EGR and lean code issues. All the P0420 code means is that under current operating conditions the catalyst cannot achieve sufficient efficiency. Fix the other issues and clear the codes, then see if it comes back. The catalyst probably is damaged, but its better to fix the other known issues that can cause a falase P0420 code to set, or can cause catalyst damage in the first place.

Running without a cat isn't going to do you any favors. Your vehicle was designed to have a cat, and the Ford engineers designed the cam accordingly. Run such a vehicle without a cat and it will probably take a hit to fuel economy because it will over scavenge.

 

Your EGR problem might not be a diaphragm leak. Mine wasn't: mine is leaking air from the vent holes on the diaphragm housing's underside to the intake manifold. The diaphragm holds vacuum during the Mity-Vac test fine.



I have an EGR valve on order. I'm chasing a P0174 as well.