HELP - Daily driver, engine backfires, no power HELP

[Trfsrfr]

HELP - Daily driver, engine missing, no power HELP

Hello,

I need help, and fast! My 93 3.0L Ranger XLT is not running right and it is my only vehicle, and I have a kid, job...

I bought this truck about a year ago, it had 159K on it. Manual Trans.
The gas gauge has been broken and I have ran it out of gas a couple times since.

Earlier today - Had my buddy hook up the A/C manifold just to check pressures, etc. All was okay, not perfect but okay. Truck cooled to 63 degrees here in Phoenix.
Then I drove an hour to pick up my son, and arrived early. As I was sitting idling for 15 minutes I noticed the temp gauge climbing, and it was time to get my son, so I left where I was parked. Then a minute later I smelled the clutch smell and now i'm blowing hot. Perfect.

Then, while driving home with my young child it just loses power. Wont rev, backfires.
I somehow limped it to the Checker and bought a new fuel pump, then limped it home.
I put the fuel pump in, and it still backfires and has no power. But at least the gauge works now!
Note on fuel pump install - I have a flatbed so was easy to access. When I pulled the pressure line off, it blew gas all over the place, coming from the engine!
So I plugged it back in, went and got a bucket, removed the connector from the line, and again it blew gas all over the place...I've never seen that before, and I had the gas cap off.

No codes that I can see. It just pops and idles super low.
I put the timing light on #1 and it jumps all over the place.
I removed the distributor cap and checked the rotor. Both appear to be in new condition.
I haven't checked anything else at this point, just wanted to get this posted in hopes that someone could help quick.

I need to have my kid home by noon tomorrow.

Help!

 

[RonD]

The fuel line to the engine will have 30psi of pressure, like a car tire with 30psi, so yes a lot of pressure, that is normal, think of what would happen if you pulled a valve stem out of an inflated tire

Could be distributor issue, slipped a bit so firing to early, timing light should show 10deg BTDC.
It's also a TFI system, I beleive, these do not like to be over heated, that A/C may have put it over the top.
Have a read here:
http://www.therangerstation.com/tech_library/TFI_Diagnostic.html

Could be tensioner on the timing chain broke, this changes valve timing so loss of compression(power) and backfiring.


I don't think the A/C work is directly related, and idling with A/C on can cause rise in temp.

 

[Trfsrfr]

Thanks for the reply Ron,
Update-
This morning, engine cold. Starts up. Idles very poorly but higher than normal, will not accelerate. Same as yesterday's condition.
No CEL.

While idling I unplugged the IAC. This made it idle down to around 600rpm, so I threw on the timing light.
It was about a 1/4 inch off of 10 BTDC, and somewhat steady there.

Then since it wasn't idled down I could hear something from the back of the engine; a spinning/rotational scrape sort of sound.
I got out my stethoscope and determined it to be coming from the distributor cap area. Maybe I spun the cap on differently after I checked the rotor last night, I dont know. Maybe it was there before.

Then I plugged the IAC back in and unplugged the TPS. This made the engine run differently and threw the CEL.
Then I plugged the TPS back in and unplugged the MAF. This didn't make the engine run different but threw the CEL.
I then took the air tube off and looked at the MAF. Looks a little dirty at the bottom area.

But the engine now accelerates somewhat, whereas yesterday at would just pop.

 

[RonD]

Yes, with the extra heat you mentioned the TFI ignition system may be the problem.

I think the CKP sensor was used starting in '91, but these sensors are usually working or not working, not intermittent, not working = no start, the CKP tells the computer that crank is turning so start/maintain spark and fuel.

CMP sensor would be the distributor on your engine, separate CMP sensors were used when they switched to distributorless systems.

You should have a MAF(mass air flow) sensor on the intake/air plenum, these can cause rough idle and running when they go bad but not sure if you would get a backfire

Bad gas can cause most of your symptoms as well, water in the gas.

Also check exhaust output at tail pipe, collapsed CAT could block exhaust, back pressure causes loss of power and could cause backfire.

 

[Trfsrfr]

I just went out and cleaned the MAF, didn't help much but it was dirty.

The engine does accelerate now, albeit poorly. Yesterday it wouldn't get past 1000rpms.

The timing does jump around a bit.
Plugs, wires, cap, rotor look to be recently replaced.
Ignition coil looks like it's been there awhile.
Would it be safe to say the coil is okay since it accelerates now?

Could a bad fuel pressure regulator be the culprit. I yanked the hose off of it and nothing changed...
Lots of black liquid coming out the tailpipe.

What about that CMP sensor? I would like to test it, but cannot find anything here on this site for anything beyond a 1995.

I wish I had a code or something...

 

[RonD]

Your year didn't have a CMP sensor per-say the cam position is part of the distributor data the computer uses.
When engines have no distributor they use a separate CMP sensor.

The vacuum hose for the fuel pressure regulator(FPR) is used to open the return line to the fuel tank when engine is idling(highest vacuum) and not using as much fuel.
Disconnecting it wouldn't change anything, just raise the fuel pressure in the rail slightly.
If that vacuum hose had gas in it or smelled of gas then the FPRs diaphragm is leaking, and that would effect operation because extra fuel would be sucked into the intake causing a run Rich condition.

All engine exhausts can produce water out the tail pipe, depends on local weather conditions as to how much.
If your engine is running poorly you will get a sooty black smoke in the exhaust, this combines with the water to make that black liquid.

The coil needs to be tested with an OHM meter, and even then it can't be written off as good.
Since the coil works based on resistance and resistance is effected by temperature, a cold coil test may not show a fault.

Then since it wasn't idled down I could hear something from the back of the engine; a spinning/rotational scrape sort of sound.
I got out my stethoscope and determined it to be coming from the distributor cap area

I might be tempted to pull the distributor, marking it's location for easier re-installation, and see what is making that noise, loose/wobbly distributor shaft or broken advance plates, ??

 

[Andy D]

The best and easiest way to test a coil , is to swap in a good one. I thought I was chasing a bad carb . Driving me crazy on Grand Wag #2. BIL says " got another coil? " DOH! Usually if a coil goes it goes, or messes up when wet, This one degraded as it went along , but never got weak enough to fail completely. The unburned gas blew up mufflers, melted the cat, but it always started and ran OK but not great.

 

[Trfsrfr]

Took it for a drive

Hey all,
Since I have had some luck with the engine running and revving in my garage, I decided to test drive it.
Wal-mart is 5 miles away.
By the time I reached home it was running like it did the other day, which is barely.
So I'm going to say the heat has something to do with it.

At least I know how much fuel I have in the tank now...

 

[adsm08]

Aren't the 93 3.0's still on the TFI system?

 

[Earl43P]

Aren't the 93 3.0's still on the TFI system?

Yes, 93 3.0 has an ICM.

 

[rich060685]

'93 is still on TFI and my brother had this same issue last year with his truck after changing the ignition coil and cap and rotor to the distributor cap this fixed his issue. Maybe you're havin the same issue.

 

[Trfsrfr]

Update -

Comp test results
1 - 95 4 - 99
2 - 111 5 - 104
3 - 100 6 - 100 tested w crappy rental tester from Autozone

Plugs look newer and burning okay.

Went through TFI worksheet
1 - Volts at pos coil = 12.04
2 - Volts at neg coil = 12.24
3 - Test light flickers

4 - Prim coil ohms = .4
- Sec coil ohms = 8.5
- Path to ground = ???

6 - Run = 12.23 volts
- Coil - 12.23 volts
- Start = .915 volts
7 - Distributor to ground = 18.3 ohms
8 - TFI to Dist Grnd = 0 ohms
9 - Hall Effect @ SPOUT = 6.584 volts

I plugged in a test light and pulled codes;
I think I got a 111, system okay
and a 121, TP Out of Range
Then a 543, Fuel Pump Monitor Circuit,
a 211, Ignition PIP Signal Erratic or Missing
then another 543.


That's where I am at. I haven't replaced anything except the fuel pump.
It starts, runs, and rev's when it's cold.
Starts to run worse after it's warm.
Idles worse now after I've done these tests.

The TFI says Motorcraft on the side of it. Could be original. Truck has 160,000 on it.

 

[aspevacek]

Throw a TFI module on that thing and get it down the road.

At the price of them and the head aches you are having it is the logical fix for your problem.

When doing a compression check it is not so much how high the numbers go but rather that the variance between the numbers that is important. A gauge could be reading off but it would read off on all cylinders and showing how all the numbers are pretty close to each other I would say compression is fine.

Swap out that TFI module. I have seen them start and run fine but if you shut off the engine you will get a no start warm condition. Swap it start it up and look at the difference it makes.

 

[Andy D]

Compression may be a tad low , but all within a narrow enough group so as not to be the trouble.Sounds as if there is something that opens and dies when it gets warm. Were plugs tan or white?

 

[Trfsrfr]

Plugs were white.