SOLVED - Strange major problem - suddenly car won´t run right, lots of blue smoke, after just sitting for a few hours

[Cees Klumper]

I went to start up my '90 2.9 Bronco II just now, and it ran really rough, sputtering, missing and had no power. It did this once before but straightened itself out, and I thought it would straighten itself out as I started driving. However, it did not smoothen out, on the contrary it started running rougher and, worse, started blowing a lot of blue smoke. I stopped the car and as I shut the engine off, I heard what sounded like faint knocking noises from under the hood. Opened the hood, and saw some what seemed like coolant on top of the driver's side exhaust manifold. I thought perhaps it had blown a head gasket, although the coolant reservoir was at its normal level and the smoke was blue, not white or grey.
After letting it sit for maybe 10 minutes I started it up again, and it ran a bit better, and there was initially no smoke. However, after maybe 30 seconds it started to run really rough again and the blue smoke re-appeared. I disconnected the MAF and then the TPS, but there was no change.
For what it's worth, it felt like the engine was firing / igniting at the wrong times. The liquid (coolant?) on top of the manifold seemed to be coming through the connection at the exhaust downpipe, rather than through the head gasket, if that's even possible, but I could not see where else it could be coming from.
I drove the car earlier today and it ran great. It seems strange that, after sitting for a half a day, it would develop such a major problem. The one thing I did do during the day, was fix two broken wires under the dash to the cruise control stalk, and I turned the ignition on and off several times in the process. So I thought maybe one or more leaking injectors may have fouled out spark plugs? The blue smoke has me really concerned. Could it be one of the main sensors to the ECU has failed? I checked for codes a week ago, and it came back all clean at that time.

Grateful for any suggestions.

 

[Paulos]

So, it ran great, you worked on some wiring, and now it's running really bad. It could be unrelated, but if it happened to me, I would suspect the work I just did to it.

If it was running great earlier, it's unlikely that the injectors suddenly have a problem. It sounds more like something isn't right with the ignition. I would undo everything you changed with the wiring (and in the process look for something you may have inadvertently changed), and start it up. Also, check the ignition module connector to see if it's plugged in all the way.

Once you get it running good enough and long enough to warm up, you can look for the source of what you suspect is coolant. Check the dipstick for an oil level that's too high and signs of coolant.

 

[Dirtman]

@PetroleumJunkie412 will fix it.

 

[Cees Klumper]

Thanks, I did unplug the cruise control wire I fixed but it made no difference. Don't think I touched anything else at the steering column, let alone something that would influence the engine running. I also fiddled with the ignition module while the engine was running but, again, no difference. Will check the oil tomorrow. Will also put in a set of fresh spark plugs just in case. Hope @PetroleumJunkie412 weighs in also.

 

[PetroleumJunkie412]

@PetroleumJunkie412 will fix it.

??

Thanks, I did unplug the cruise control wire I fixed but it made no difference. Don't think I touched anything else at the steering column, let alone something that would influence the engine running. I also fiddled with the ignition module while the engine was running but, again, no difference. Will check the oil tomorrow. Will also put in a set of fresh spark plugs just in case. Hope @PetroleumJunkie412 weighs in also.

Probably TFI related. Disconnect spout connector and listen and drive. If motor is smoother, but no power, likely TFI module partial failure.

If not, then coil or distributor related. Possible fuel issue as well. Joys of OBD1.

Age of cap, rotor, wires and plugs? Plug type and gap? Brands of each?

Coil type, age, and appearance? Rf capacitor installed?

Suggest disconnect spout and drive. Send us a few photos of a few plugs and cap and rotor.

Check base timing. Should be read from needle at 10BTDC.

Perform KOEO and KOER tests. Let us know what codes. Wait for stored codes.

We'll walk you through the diagnostics. Start with above. Counterintuitive on some things, but great engine to learn efi on due to simplicity.

My 2¢. But hey, I just work here. Back to mopping coolant.

 

[RobbieD]

Definitely start following the steps that PetroleumJunkie laid out. But-

. . . The one thing I did do during the day, was fix two broken wires under the dash to the cruise control stalk, and I turned the ignition on and off several times in the process. . . .

Is your cruise control not buttons on the steering pad?

Your describing it as a "stalk" has me wondering if your cruise control is aftermarket, not factory installed. Aftermarket wiring can be a real can of worms sometimes, and I'm also struck by the "coincidence" of your fixing the wires and then the problem showing up.

 

[PetroleumJunkie412]

Definitely start following the steps that PetroleumJunkie laid out. But-



Is your cruise control not buttons on the steering pad?

Your describing it as a "stalk" has me wondering if your cruise control is aftermarket, not factory installed. Aftermarket wiring can be a real can of worms sometimes, and I'm also struck by the "coincidence" of your fixing the wires and then the problem showing up.

YOURE A STALK

But also. Damn fine observation.

 

[RobbieD]

Well, I have been called worse.
Beats being stalked, or a stalker, though.

 

[PetroleumJunkie412]

You'll never know if you have a good stalker. You'll never know they're there.

 

[Locotomb]

Alright, lets get away from the creepy and back to the 2.9l. I was thinking, he said Maf. So I assume the 1990 2.9l runs a maf setup. I knew that, So does the Maf system still use a map for the initial Barometric reading when you crank the vehicle? If so, you could be getting a bad Baro reading causing the missfires and blue smoke.

 

[rusty ol ranger]

You *sure* its blue smoke and not black?

Its highly unlikely it would begin burning massive amounts of oil that quickly.

Pull the vaccuum hose off the FPR (fuel pressure regulator), see if theres gas in it.

Very common thing on 2.9s.

Also check/replace your PCV valve and check the hose for any obstructions

 

[PetroleumJunkie412]

Alright, lets get away from the creepy and back to the 2.9l. I was thinking, he said Maf. So I assume the 1990 2.9l runs a maf setup. I knew that, So does the Maf system still use a map for the initial Barometric reading when you crank the vehicle? If so, you could be getting a bad Baro reading causing the missfires and blue smoke.

Only 2.9 Rangers that have MAF are California emissions trucks. Very uncommon.

 

[Locotomb]

Thanks for the info PetroleumJunkie412. I have seen one at my local Yard. Must of been a CA car. And I just looked. He's in CA. What are the odds? lol Thanks again..

 

[Cees Klumper]

Thanks all of you for the many great tips. I feel like I got to know this truck a WHOLE lot better in the past few hours.

So ... the issue was the fuel pressure regulator (prize goes to Rusty). The diaphragm or whatever is inside had clearly broken because it was dumping lots of gas straight into the intake manifold, through the vacuum line. It must have pumped about 2 gallons worth into the intake. Come to think of it, I better replace the oil and fillter as some of it probably washed down the cylinder walls, past the piston rings. Raw gas was coming out of the tailpipe!

First I replaced the distributor cap, rotor, spark plugs and the ignition module (applying the layer of grease that came with the module), thinking the problem was ignition related. Last week I had already put in fresh spark plug wires. However replacing all these ignition components made no difference, still the same bad symptoms.

So my neighbor, a retired longtime Ford mechanic who worked on these cars who was helping me, and I went for the next thing (fuel) and when we pulled the vacuum line off the regulator, fuel just ran straight out. I turned on the ignition and it just squirted out of the vacuum line. So I got a new regulator (thanks for auto parts stores who have all this stuff in stock), installed it with a new fuel hose (the PO had fitted a piece of too-large diameter coolant hose), and ...

It started up and immediately ran fine, on all cylinders and smooth. There was still a huge cloud of blue smoke coming out the tailpipe but my neighbor said not to worry, it is just burning up all of that raw fuel. Probably this was gas mixed with 'washed-down' oil. After a minute or so the exhaust color started to turn grey. It kept smoking like this for about 5 minutes, burning up the raw gas in the exhaust, and then the smoking stopped. I went on a 15 mile ride and it ran super sweet. Even the cruise control (my yesterday repair) now works. It's most likely an aftermarket unit. No buttons on the steering wheel. But it works fine.

The only change now is that it upshifts a bit quicker than before, making the car a bit 'lazier'. It was probably running rich all the time as I suspect the FPR had a small / pinhole leak before it completely failed yesterday. I checked the mileage for the first time yesterday and it was around 12 MPG over the 5 weeks since I boughg the car. I filled it up again and will monitor mileage.

So all's well that ends well. Turned out to be something relatively simple and inexpensive. Plus now I have most ignition parts new, which is nice to know. My only worry is the gas may have ruined the cats, and/or the oxygen sensor. The check engine light is not on though. I will check for codes in a couple of days, after changing oil + filter.

Thanks all again, I do love this little truck!

 

[alwaysFlOoReD]

Thanks for posting the detailed update.