My 1991 Toyota Celica is only getting 9MPG! HELP!

My Toyota Celica has a 5SFE, 2200cc 4 cylinder motor in it, of which I normally get approximately 23mpg from. Now suddenly, it is smoking white smoke while idling, has an engine miss during the 3000-4000 RPM range, and I am lucky to get 160 miles out of a 16 gallon tank of gas. The smoke smells like gas, so I am guessing it is using too much. That, and the fact that I am suddenly getting such lousy fuel mileage. I have checked the plug wires, fuel pressure relay switch, and a few other things. Anytime I try to jump the diagnostic box, even after leaving it unhooked for 30 minutes, I am still getting no codes. Only a repeated flashing. I stopped counting the flashes after 125. I am completely stumped by this. One thing to note: when I unplug the engine compartment fuse labeled “fuel pump”, nothing happens. This is the only car I own that has an air conditioner, so I am really sweating the thought of not having this car as my daily driver. Any advice is welcome.

The fuel pressure regulator may be bad.

I’m afraid I don’t like the sound of this.

White smoke usually means coolant. Lots of white smoke means lots of coolant. That could prevent ignition and cause the raw gas to get blown out the tailpipe along with the smoke.

Forget the diagnostic box. It won’t help on this one. My guess is that you’ve blown a headgasket and your piston(s) is(are) pulling in coolant in large amounts with every intake stroke. Check your coolant and see (1) if it’s dropping and (2) if it’s contaminated. If it is, you need to have this engine evaluated. It may be toast.

Did this engine overheat anytime recently? Ever? Badly?

Post back. We care.

This isn’t very thick white smoke coming from my car. I’ve seen blown head gaskets before, and I truly don’t think this is the problem. I have yet to run a compression test, due to the cost, but I have not noticed any contaminants in the coolant. All of these problems started (I think) when I removed the battery for charging. Could this be related? I hope it is something simple like a head gasket. I just rebuilt my 1988 Honda Civic completely, so the process is still fresh on my mind. I prefer working on Toyotas over Hondas anyway, so maybe…What else can I try besides a compression test? The oil is fine, although it does smell of gasoline. If I had a blown head gasket, wouldn’t it turn my oil milky like it did in my last car? Thank you for your advice.

where is the fuel pressure regulator on this car? The fuel rail, maybe? How can I test my current one? I really need to get this car fixed soon…

How many miles on this Celica? You only got 23 mpg before the problems started? That’s not much for a Celica. These problems may have been developing for a long time.

Everything seems to point to excess fuel pressure or leaking injectors, or both… There’s too much fuel going into the engine. That’s why the exhaust and the oil smell like gasoline.

You’re going to have to have the fuel pressure tested, and perhaps the injectors, too.

If the head gasket were leaking, and water was the source of the white smoke, you’d be losing coolant. Are you losing coolant?

I don’t think removing the battery has anything to do with this, but why did the battery need to be charged outside the car?

there are 210k miles on my Celica. The reason I get 23 MPG is because of how I drive. I am younger, and I can’t seem to remove the lead from my right foot. When I loaned my mechanic the car for a couple of weeks, he was getting right around 30mpg, so I know it is my driving style. The problems just started instantly with this car, rather than slowly. Got in one day, turned the key, and BOOM, smoking, idling rough, and missing when I drive it. Especially when it is in gear, coasting down the road. I either have to have my foot off the gas, or really lay into the throttle when I drive it. If I try to feather the gas and accelerate slowly, it bucks and jerks. I have not lost an ounce of coolant. I took the battery out to charge it before I placed the battery into my alternate vehicle, which is a 1988 Honda Civic with 218k and a fresh rebuild. I would be content to drive that one if it had AC and did not need a CV joint replaced. It gets really humid up here in the NC mountains, and after working 8 hours in a hot factory, welding aluminum, I love nothing more than getting into my Celica, cranking up the AC and going home. As opposed to getting into the Civic, rolling down the windows, and roasting. How do I test the fuel pressure on this Celica? Isn’t there a valve on the fuel rail somewhere? Thank you for your advice.

I have yet to run a compression test, due to the cost, but I have not noticed any contaminants in the coolant…What else can I try besides a compression test?

The symptoms of a blown head gasket will vary with which of oil and/or coolant and/or cylinder contents is leaking to which – and how much. But I’m inclined to agree. Very likely it’s not a head gasket problem.

Perhaps you should pull the spark plugs and see if any of them looks distinctly different from the others. e.g. if one of them is shiny clean, you are surely steam cleaning that cylinder with coolant. If one is covered with crud, it’s probably not firing. Etc.

" have yet to run a compression test, due to the cost"

How much is someone trying to charge you for one. You can buy a tool and DIY for very little and not much more to have it done professionally (more accurate) Have you looked at your spark plugs? They all should look the same. They can tell a story if you know how to read them.

From what you say the trouble is most most likely due to a bad fuel pressure regulator. Look for a device tied to the vacuum system with a small hose and is also tied to the fuel system. Looking at some pictures from the Autozone site it may be near the intake manifold piping. After you fix this you should change your oil. It sounds like it is contaminated with fuel.

Here is a link to a site showing what they look like.

Do you have a repair manual for your car?
Here are instructions, and drawings, which show how to replace the fuel pressure regulator:

There probably will not be a schrader fitting for measuring the fuel pump pressure. What you usually have to do is get a longer banjo bolt for the fuel filter, a second banjo fitting, and multiple copper washers. Some mechanics take a long banjo bolt, cut the head off, drill down the center, cross drill at the banjo fitting level, seal a nut at the original banjo bolt head level, and shape the exposed end to take a fuel pressure hose. I am looking for an adapter banjo bolt which is shaped the same with a schrader fitting on the extended top that could be installed once and left in place. But I haven’t found one yet.

I am wondering if the white smoke; rough idle; gas smell at the exhaust; and low mileage might be a fuel injector stuck ‘on’. At least first check that the fuel pressure regulator vacuum line does not have fuel in it. Then when you check the fuel pressure see if the pressure holds after the fuel pump is ‘off’. If the fuel pressure drops immediately after the engine is shut off, you could have a leaking/stuck injector or a leaking pressure regulator. If the pressure holds with the fuel pump ‘off’, turn the key to the run position but do not crank. See if the pressure now drops. If so there maybe a short in the grounding of one of the injectors or the open collector in the ECM to an injector may be shorted.

Get back to us with the progress on this interesting problem.

Here is a set of fuel pressure test adapters: A conscientious mechanic would get/have these (hint, hint). …or, will we remain at, “I been thinking about that…” ?

This may be what you are looking for: