[Rilea]

I know this is my first post here, but honestly, I've exhausted all my other avenues on this and even my master mechanic friend came up blank on this one.

History:
Car belongs to my wife's mother, she's had it for maybe a year, and she said it would occasionally lose power at stops requiring more gas peddle to keep it running. About a month ago, she ran it out of gas, and a friend brought over a tank of gas for her, and they got the car to her house, where it ran no more. She had another friend come look at it, didn't sound like the guy knew what he was doing, but he told her that she probably needed a fuel filter or her timing "belt" had failed (on a timing chain engine), then bolted.

Current Status:
Turns over, if you let it sit for 30 minutes or more then try to start it, it will sputter like it's trying to start, then die. Otherwise, it just turns and turns and turns.

No codes on the computer first off, of course, she and the guy that was looking at the car ran the battery dead before I could get to it, so maybe there were codes before it totally died. We keep having to recharge the battery with a trickle charger due to lots of testing. Battery will hold charge untouched though, so the battery is good.

So, had no fuel pressure, spark plugs were worn and fouled all to hell, oil was ancient (she hadn't gotten an oil change since she purchased it).

Checked compression - ~120PSI average on all cylinders (timing should be good then right?)
Changed oil/oil filter
Changed air filter
Replaced fuel filter, pulled and cleaned fuel injectors - 40 PSI at fuel rail (checked with a tire gauge, all the rental units in my town were broken, and the two I ordered online came broken)
Replaced spark plugs, wires, and coil packs - strange spark timing, check tach, no reading
Replaced ICM - tach is reading properly
Replaced Cam position sensor - Spark timing now seems to be accurate (checked by pulling a big no no - pulled plug, connected to wire, placed over plug hole, turned over engine, perfect little flames, although they were only about 6-10 inches tall)
checked impedance on IACV - 9Ω
checked conductivity on all wires between ICM and coil packs, all zero (no connection faults)
checked throttle position sensor, varies from north of 9KΩ down to 0.3Ω, so... perfect there
checked power to MAF, all good
checked MAF sensor - clean
checked signal from MAF removed from car in open air - With car on, voltage began to rise from 0.3V up to 0.6V when I stopped, figuring it was good.
Checked every fuse I could find, all good, checked the one relay I could find under the hood, all contacts good except for the switched point.

I don't have a timing light, I don't have access to a proper fuel pressure gauge, I don't have a multimeter that reads frequency, and I only have a basic OBDII code reader, no diagnostics. Biggest issue is that I'm doing most of my work in the dark, after I get off work, in her driveway, so I can't really pull the intake manifold or anything, or at least, I don't want to yet...

I'm almost ready to light this thing on fire, and she keeps wanting to take it to a mechanic in the area. I'm only $300 into the car so far but I can't help thinking that if it goes to a mechanic in town, she won't be able to afford to get it back. We're a small town, and the only mechanic that didn't screw people in town has been out for a month...

Any suggestions would be helpful. I'm planning on pulling the back seat this weekend, pulling the fuel pump, and cleaning all of its filters in the hope that it fixes things.

 

[Aussiblue]

The pump may have died. See if you can hear it running.

 

[Rilea]

The pump is running, you can hear it every time you turn the key, and the fuel rail will pressurize when you turn the key if you relieve it beforehand.

 

[Bert]

Have you sprayed carb cleaner in the air cleaner and then try to start it?

 

[Rilea]

I have yet to try carb cleaner, if I have the time, I'll give that a shot this week. I'm assuming if I get it to start in that case, I'm looking at a fuel problem?

 

[R.S.LOGAN]

With the history of the battery and trickle charging , wouldn't do any harm to get it load tested . Any weak cells and on cranking will draw away most of the spark needed at plugs .If possible , hooking up a good battery with jump leads to give it a extra boost might help . None of the " friends " altered the firing order perhaps ?

Mercury Workshop Manuals > Cougar/XR7 V8-281 4.6L SOHC (1995) > Powertrain Management > Tune-up and Engine Performance Checks > Firing Order > Component Information > Specifications > Page 3374


https://books.google.co.uk/books?id=myKJTE_3YrAC&pg=SA15-PA1&lpg=SA15-PA1&dq=95+Cougar+4.6l++firing+order&source=bl&ots=HbCqer6apm&sig=V9wILtN2mi_8yN_dFdrr52dspgw&hl=en&sa=X&ved=0ahUKEwjs1ozXvvHRAhUeOsAKHcWsCVIQ6AEITjAL#v=onepage&q=95 Cougar 4.6l firing order&f=false

 

[Aussiblue]

Have you sprayed carb cleaner in the air cleaner and then try to start it?

Don't they have a Teflon coated throttle body (and a warning sticker not to use throttle body cleaner) and need special Teflon friendly throttle body cleaning spray and definitely no carburettor cleaner? Although perhaps in the last 20 years it has already had the spray cleaner treatment and no Teflon is left.

 

[Bert]

Don't they have a Teflon coated throttle body (and a warning sticker not to use throttle body cleaner) and need special Teflon friendly throttle body cleaning spray and definitely no carburettor cleaner? Although perhaps in the last 20 years it has already had the spray cleaner treatment and no Teflon is left.

Yes, but just spraying in the air cleaner shouldn't affect that.

 

[Rilea]

When I did the plugs/wires, I used the Chilton manual for the timing, but I'll double check against that picture again. Thanks for the notes on the carb cleaner and coated intake too.

 

[maswov]

Take a look at the emissions control system, erg valve or catalytic converter maybe.

 

[Aussiblue]

Yes, but just spraying in the air cleaner shouldn't affect that

Using it like Aerostart Aerostart - CRC Industries ? Worth a go; if it runs for a second it would suggest it's a fuel supply or fuel quality issue.

Any chance the new fuel filter was put in back to front (arrow pointing to tank instead of engine)? The history does suggest that crap from the bottom of the tank may have got into the system. Did a lot of debris come out of the old filter?

I assume the fuel tank has been filled and you are not relying on there being enough left in the tank from the small can rescue fill.

 

[Rilea]

Any chance the new fuel filter was put in back to front (arrow pointing to tank instead of engine)? The history does suggest that crap from the bottom of the tank may have got into the system. Did a lot of debris come out of the old filter?

I followed the mounting arrow of the new filter when I mounted it, but yeah, there was some nasty stuff that came out of the old one when it was removed. It was one of the first things I checked. This weekend I'm going to try the carb cleaner in the airbox start method, and if that works out, dive into the fuel pump.

Thanks everyone for all the suggestions so far!

 

[Aussiblue]

I followed the mounting arrow of the new filter when I mounted it, but yeah, there was some nasty stuff that came out of the old one when it was removed.

Given that, I would also try and clean out the injector fuel rails in case some fine crud has got past the filter and is blocking the injectors. Remove one rail first (whatever one is easiest) and see if any crud comes out before you perhaps waste time removing the other. If you get crud fill the rails with injector cleaner fuel additive when you reinstall them (although ultimately you might have to have the injectors cleaned or replaced). This will also give you a chance to see if fuel is getting the rails; if they are dry you have a pump or other problem between the rails and the tank.

 

[CatSkinner]

Agree with Aussieblue. Fuel delivery from the injectors may throw a lean code if left running from a while, but blockage that doesn't allow it to run very long will never get picked up.

 

[Bert]

If the cats are plugged it won't start either. Try the fuel deal first. If it doesn't, removing the O2 sensors to let it blow out there and try to start it. That would rule out the plugged exhaust.

 

[Rilea]

Good news and bad news.

First off, thanks to everyone for all your help, I tested with carb cleaner with no change in engine behavior, so at least I know it's not a fuel issue.

Bad news, can't pull the O2 sensors or the cat to test, the whole underbody is rusted solid. Entertained the idea of cutting it out for about ten seconds, till I looked online and found that the only cats I can find that are made for the car... can't be shipped to CA lol. So, I'm really glad my wife and I are only about $200 into this, but we're looking at calling it a loss. Mother-in-law is currently saddled with my backup car.

Thanks again to everyone for their ideas, we're gonna look at what we can get for the car from scrapyards and such. I may be parting it out soon, dunno, depends on the local market.

 

[Bert]

Thanks for the update. You did check for spark when cranking right?

 

[R.S.LOGAN]

Cant drop / loosen front pipes from headers or probably seized solid also ?

 

[Rilea]

Bert,
Yah, spark is timed with the injectors and working perfectly.

Logan,
no, the nuts are frozen solid and I can't get a strong enough angle on the upper nuts to release the y-pipe/cat pipe from the headers.

In all honesty, I'm willing to cut off the whole cat/y-pipe, but in our small town, the prospect of having a new custom cat/y-pipe welded up would be greater than the value of replacing the car. I'm just not up for pouring that much money into it.