Underpowered Honda

I have a 1990 Honda Civic that my dad (I’m 18) recently bought for me off a friend of his. The car runs incredibly well; so much so that I don’t have any complaints about it at all. It even has a reasonably custom paint job and this friend has invested a fair amount of money into the wheels and tires, which leads me to believe that it has been well cared for.

The engine is (to the best of what info I have) an OHC fuel-injected I-4 with a 1.5-1.6L displacement.

However, I do have a question about something that’s recently been bugging me. Several months ago, dad and I were taking a short road just for a quick scenic drive. He had me wait a little bit at a rr crossing to let the car in front of us gain some distance just to see how the Honda could perform. I hit the gas and the engine just…died. Wouldn’t have been a problem if there weren’t any railroad tracks! We couldn’t get the car started again without pulling the key all the way out. A couple weeks later, the same thing happened at a four-way stop (a busy one to boot).

My car has also attempted to stall dead a few times, all averted by a brief removal of my foot off the accelerator, and there’s a certain band in the revs that, in a certain gear, have absolutely no power whatsoever, and the car has very poor acceleration even in lower gears. It did not run like this when I initially got it.

All of these occurrences have led me to one of four conclusions: clogged air filter, clogged fuel filter, gunked-up injectors, or a failing fuel pump. I checked the air filter Friday afternoon, and the thing looked like it was brand new! Just ruled out the cheapest to fix suspect. I had also put some new oil into the car half a month ago. I was wondering if anyone had any other input for what might be the problem. It could be that the car is just old, but it was quite peppy 500 miles ago.

I dread taking the car to a mechanic for inspection. Checking the injectors would involve pulling the engine head, and checking the fuel pump and filter would involve draining and pulling the gas tank. Both time-consuming and costly. ><

The injectors are not likely the problem at all and you do not have to pull the head to check injectors.

Checking the fuel pressure is done with a pressure gauge and does not involve draining anything. The car should have a test port underneath the hood. A gauge can even be fabricated pretty cheaply if need be.

Given the key comment, some of my first suspects, and a common problem, is the electrical part of the ignition switch and/or the main relay.

Without knowing if the problem is fuel or spark related those are what I would consider first.

I should have added that gunked up injectors or fuel filter is not likely the cause of this problem as those are not (normally anyway) a come and go thing.


Checking the injectors would involve pulling the engine head …
Checking the injectors could be done with a pressure gauge by grounding each injector individually (KOEO) and looking at the pressure drop as each injector fires. For a clogged injector the pressure drop would be significantly less than the drops for the other injectors.

Injectors can be cleaned without removal from the engine by running a concentrated cleaning solution through the fuel rail with the gasoline line plugged or diverted back to the tank. You would have to take the car to an auto shop having the proper equipment; this is not a DIY job.

I also doubt if it is the injectors. I would suggest a fuel filter should be your first change. If the air filter, plugs or wires have not been changed recently, then you should get that done as well.

What you experienced is not all that unusual. There was a good chance that you were stopped on an upgrade, that makes pumping the fuel more difficult and it can also cause the gunk in the bottom of the fuel tank to move around and maybe clog the fuel intake. It also points to being careful at those crossings. Don’t ever try to beat the train! That hesitation has killed more than one driver who may not have seen that second train on a different track or did not want to wait for it, and was not able to move fast enough.


I also doubt if it is the injectors.
What are your reasons for doubting it is the injectors? Inquiring minds like to know.

The rail line I was crossing is (for the most part) abandoned, and I wasn’t trying to beat a train. The only train that ever runs through anymore is a once monthly tourist trap from the local Depot Museum–a rusty old EMD F7 coupled to a few equally rusty coaches. Yes, I was on a slight incline, but it was an up hill relative to my car’s direction and I thought the fuel pump was near the front of the tank.

Also, on further inspection of my engine (all I had to rely on last night was a cruddy flashlight to look at the engine), the carburetor says 4-port programmed fuel injection on the top, but the engine head says 16 valve. Oo

I don’t know what to believe anymore. It’s like Honda didn’t know whether or not to make the engine in my car a standard fuel intake or an injection system. ><

This could be wrong, of course, but you may have a bad throttle position sensor. When you snap the throttle open and get nothing, it could be the problem. There are many possible causes and getting your codes read could be a good first step. I agree with the other posters suggestions too.


It’s like Honda didn’t know whether or not to make the engine in my car a standard fuel intake or an injection system.
In the early 90’s, Civics had either a single-carbureted, double-carbureted, dual-point injected (two injectors for four ports) and multi-point injected (4 injectors for four ports) systems. If your engine is four-point injected, than it is the best engine that Honda made for Civics in the early 90’s.


This could be wrong, of course, but you may have a bad throttle position sensor. When you snap the throttle open and get nothing, it could be the problem.
There are two things going on here: The output of the throttle position sensor is a voltage that indicates to the computer how open the throttle is. If you gradually increase the throttle, the computer responds by increasing the on-time of the injectors. However, if you quickly snap the throttle open, the computer sees that the TPS voltage has changed rapidly with time. That is, the computer thinks that an instantaneous acceleration in speed is requested, and it responds by immediately injecting more fuel into the cylinders for an instant. It is very similar to the accelerator pump circuit in old-style carburetors. Stomp down on the throttle and the spring-loaded pump piston in the old-style carburetors squirts an extra shot of fuel into the cylinders. Because his car stumbles on acceleration and not at high speed, I don’t think it’s the TPS (nor the fuel pump/filter either, as Meehan thinks). The TPS is easy to test, however, with a VOM.

There’s a problem with getting the codes read. I’ve checked every nook and cranny in my car (even squishing myself into the limited real estate under the steering wheel) and I can’t find any semblance of an OBD port.

The ECU should be underneath the passenger side carpet and underdash panel. It has an LED and a test connector to be used with a VOM.

From the sound of things it appears that you think the ECU may hold all of the answers to your problem and this is not the case.
There are dozens of reasons why your car may act up and none of them will leave a code.

I’ll stick with the main relay, ignition switch, ignition module, and even possibly the fuel pump.
A pump can come and go like this. They may work fine for 500 miles, quit, straighten up and be good for another 300. Who knows.

When the engine flat quits with no sputtering this could point to the ign. switch.
If there is any stalling and bogging involved, then you may have a fuel pump problem. The main relay is also affected as a dragging pump can overheat a main relay.

Hondas were in a world of their own during this period. They were involved in a big law-suit with Bosch over fuel injection. That’s they changed systems every two months…They are a nightmare to troubleshoot.

You have not mentioned how many miles are on this car. That might be helpful to those trying to help you…Also, has the timing belt been changed? When? Is this an intermittent problem meaning it runs fine sometimes? With the limited information you have given us, the fuel pump may be getting weak, occasionally losing pressure…

These old Honda’s have a 2 pin connector just above or just behind the top of the passenger side kick panel. You short the two pins with a paper clip or short piece of solid wire, turn the key to the on position, but do not start the engine. The check engine light will flash the codes. The ECU is in this area too, where OK said, I don’t remember seeing an LED, but maybe, I never had to pull one out.

I would be concerned that the timing belt might have jumped a tooth when you floored it the first time, but if the fuel injection is a single port type with a accelerator pump, the accelerator pump could have gone bad, but you said it was a four port, so that should not be the problem. A weak fuel pump could have these symptoms, unable to deliver enough fuel under heavy loads. A clogged fuel filter could also be to blame.

I would start with the easy stuff . . get the performance up to specs. How long since a tune up? New plugs, wires, cap and a can of seafoam in your gas tank, check your ignition timing. Check your tire pressure (no kidding!). Change the air filter. The fuel filter(s) on this model are easy to change, do 'em. And an oil change. Post back before you go changing anything else, this could get expensive and you probably could diagnose and cure this hesitation by starting simple. And one more thing . . . don’t expect V-8 performance from a 17 year old four cylinder. Good luck! Rocketman

I don’t know when my car was last tuned up. My dad bought it used for $1500, and it’s nearing 200,000 miles. I think it’s up to about 196,000 miles right now.

Also, I checked the engine again today when I took my car to an Auto Zone. The carb says two-port fuel injection. Also, the Auto Zone guys checked the battery, and it only has 7 volts. It could be that the battery is my problem. I’ll have to talk to my dad about getting a new one, but it shouldn’t be too hard.

I don’t know if this is true for your Honda, but the engine computer (ECM, PCM?) needs a minimum voltage to function. If the battery voltage is that low, it may not be working correctly.

More than likely you need a new battery, but before you go out and buy it, try charging the old battery first to see if you can get the battery voltage back up to 12 - 13 volts and see how the car runs. I discharged a 3 year old battery down to 7 volts last year, but it took a charge and is working fine. If the battery has one or more dead cells, you will not get the voltage up no matter how long you charge it.

Good luck,

Ed B.

My dad didn’t have enough money to buy a battery, but mum took me to the auto store and got one. The Honda is running much, much better now (exactly like it ran when I first got it).

But there’s another odd problem that’s starting to surface. Occasionally, when I hit the brakes to stop at a light, the steering wheel tugs to the right. I actually have to fight it to keep the car driving straight on these occasions. Could it be that I have uneven brake pad wear in the front brakes in which one pad has more friction than the other? A small squeaking noise is coming from one of the front wheels when I stop now, so a brake servicing is gonna happen sometime soon.

Yes, uneven brakes can do this and considering the car has almost 200k on it you should inspect the front suspension.

A badly worn ball joint can also cause this, and is a real serious safety issue.

The ball joint sounds like something I should leave to a mechanic to fix.