1991 Acura Integra LS - Poor Acceleration

You do the rebuild, or a mechanic?

It was indeed rebuilt by a mechanic local to me. I have a bad hip and though I would like to take it back in for them to fix, fear follows.

Thank you for responding

Take it back to them, and explain everything you are experiencing since the rebuild. Any honest shop will diagnose, and usually repair for no charge if it was something they missed, or overlooked during the rebuild.

Anytime you change the water pump - go ahead & put in a thermostat - but anyways...for now I wouldn't worry about bad impellers on the new pump - I would go ahead & put a new thermostat in now - get one that is rated to lock open when the engine overheats - a little more pricey, but worth it....is the engine getting to where you have blow-by. or discharge on the reservoir when it heats-up?

How many miles are in the new break-in period? you say that power is lower, but have you settled-in all the components? I don't think you need a quick fix here, if not broken in - you need to wait (but change those darn spark plugs)

If the Heads were turned & bored, your going to have some noise difference, without keeping spec to the changes on everything else that bolts back on...

"Anytime you change the water pump - go ahead & put in a thermostat"

-True, But I would like to add...

I also strongly recommend (on imports especially) changing the timing belt anytime you change the water pump.
You already have to have the cover off, and it right there, and a loose/worn timing belt can cause issues, not to mention when it breaks on an interference engine, nearly all will be lost.

(I enjoy Run-on's)

I didn't change the spark plugs when I replaced the CAP, ROTOR and WIRES because the invoice stated they had been added when assembled (I trust'm?) In looking over the invoice I see no mention of a water pump replacement nor timing belt but I must add that even though these items are important and cannot be over looked, were running perfectly before the overhaul.

The car has roughly 15 miles on it since I got it back. I have driven it twice only to validate the problem still exists and that changing the cap, rotor and wires didn't fix the problem. I suppose the next thing I will do is take out the thermostat and replace it. I will try and find one as mentioed that remains fully opened on overheat, but I am not sure about the availbility of such a device, but I will check. Then if I find nothing from that I am going to go ahead and do the block check. Seems to me once while I had the engine running with the radiator cap off their appeared to be an uneasiness to the water flow. For whatever reason, the fact that driving the car causes it to heat up, yet it cools while standing still with engine running holds more to the answer than I am seeing, so first the thermostat. Something is restricting the water flow.....

Again, thank you for your input

It is amazing how you can spend years building engines, working on cars and doing all sorts of things like that. When it works it works. But then you end up learning ten times as much while trying to sort out just one problem, maybe two. You know, now that I know what it is I will look here first next time.

My first car was a 1984 Mercury Topaz. It was my dads car and the engine went out just after he bought it, used of course. The rebuilt engine had the same problem you had. It ran hot, had poor power and fuel mileage. I got it handed down to me for my senior year in high school. Ten minutes with an accurate timing light, a set of plugs, plug wires, distributer cap, and rotor and it suddenly had great power and went from 18-22 MPG to around 30 - 36 even being driven by a teenager.

Point is your ignition system likely should get a new set of plugs, plug wires, distributer cap and rotor (if equipped) and a proper timing setting. If its not that they may have the cam timing off by a tooth or two. Many engines will tolerate a miss timed cam to a limited degree and run but not well.

All of the burning oil the old engine did may have plugged up the exhaust system too! Catalytic converters don't take oil burning well and can easily cake up and plug. That leads to low power, high exhaust back pressure, and excessive heat build up in the engine as well.

I am afraid I am going to have to go the way you mentioned and check the cam timing. That is something physical and fairly easy to see once you open the front of the engine up.

As for the oil consumption. I don't think the car really used all the oil. When adding oil to the engine the bottles I used fit the oil filler hole really well, and while squeezing the bottle to get the oil out I could hear air passing into the engine, like there was an open hole in the block. Then, while driving the car after filling it, during starts and stops, I could smell oil, raw oil, not burnt. This leads me to believe the oil was leaking out somehow. Though I must say I never did see any puddles under the car Besides if that much oil was passing through the exhaust, you wouldn't be able to see for the smoke.

Let's also not lose sight of the fact that if all this potential oil had pluged up the converter, it wouldn't have been an over night thing, it would have been gradual. Please keep in mind this engine/car ran fine until the engine was rebuild.

Thank you..

To me it sounds like the ignition timing is advanced too far. If you have a timing light or access to one I would recommend checking it if for no other reason than it is an easy place to start. I am not sure if a 91 Acura has a mechanical advance, but a broken or missing spring on the distributor flyweights will produce those exact symptoms. The car will idle fine, but as soon as you are above idle the timing advances too quickly generating a lot of heat, but not much power.

(1) Was the block deck machined down to level it and remove surface imperfections? Also, was the head machined as well for the same purpose?

If either have too much material removed, it can throw the cam timing off AND cause overheating. I would verify this with the shop. Also, have the cam timing checked to ensure (even if the head and block are machined correctly) to ensure it's correct.

(2) I would install a temp gauge for test purposes to determine just how hot it's getting.

(3) Basic ignition testing to ensure proper operation may be a good idea.

(4) Make sure the EGR system is operating properly. It can cause poor performance and overheating in certain circumstances, if it is not switching on and off as designed.

(5) Correct pistons for application? Probably are, but too much compression can cause overheating.

(6) Ensure cooling system is circulating as needed.

It sounds like the cam timing or the ignition timing is the issue. Could the distributor be off by a tooth resulting in ignition timing that's either too far advanced or retarded?

I would check for plugged exhaust.

I am going to run with the timing is some way being the culprit right now. I started it this morning and it seemed to run very well at first. Engine seemed much more responsive that it had before I changed the cap, rotor and wires. Only problem there was that once it warmed up it started to run crappy again. The warmer it got the worse it became. In any case, I drove it down to the garage where it had been rebuilt and set up an appointment for Friday for them to look at it again.

I did ask about the machine work that had been done asking if the block had been cut at all. They said no, only the head was surfaced to ensure flatness.

As for the 'plugged up exhaust'.. If I am wrong I will slap myself for not listening and will profusely apologize but like I have mentioned before, this car ran superfine before the rebuild. Plugged exhaust just doesn't just happen. Now on the other hand if a baffle comes loose and closes something off, OR if by some chance something was dropped down the exhaust pipe while the exhaust was open... oooo, the plot thickens, hmmmm. Shows to go ya, any thing can happen...

And the beat goes on....

Sorry it has been so long since I made any further comments on my 91 Integra but the garage still has it which in one way is good and another, not so.

I took it back in early morning on the 31st of August. They said they would put somebody on it right away. The shop is really slow right now (go figure) so they only had one mechanic working. Anyway to try and show them trust, faith and all I waited until Thursday of the following week before checking on it. Ok, so I go in and the person working the counter says they had worked on it and found the timing belt was off a tooth and they had fixed and had found one tappet making noise (ewww) fixed that but that they were waiting for a thermal control for the fans (the freaken fans again) which right then told we they had the damned car again for almost an entire week and probably had done little or nothing. Sounds to me like they sat on it figuring that once they got the fan control everything was going to be fine.

I told this person when I took the car back in that the car ran really (fairly well) when it was first started in the morning but became rapidly worse as it warmed up, which it did (warmed up) pretty darn fast. Once it gets fully warm it becomes REALLY poor in response, very throaty full throttle, will hardly pull the car from a standstill.

In any case, they told me that once the fan controller came in they would install it and drive it thinking everything would then be ok. I tried to explain to them the car ran fine before they did their rebuild with the damn fans being the way they were, what made them think they were going to make any difference now...? They went on to tell me how these fans NEED to start up at 210 degrees in order the keep the temp down. I again tried to explain to them had this been the case why then would the car run over temp but then while idling, the temp would then drop.

They simply do not hear.

Now, with my faith mostly gone cause they are so hung up over that fan control they are never going to find the problem.

Oh well, funny thing, I never did hear from them on Friday the 7th so either they didn't get the fan control or if they did, they found it didn't fix anything. We will see what we will see..

The plot thickens.