phil_eg_civic

1993 Honda Civic eg D15 non vtec

I have been fixing my hondas for 16 year, so this problem has been driving me crazy!

Problem: (Civic C.E.L. works, but will not give me a code) As soon as you start up the civic the car revs from 1100rpm to 2100rpm up/down constantly.

While driving the car in first gear in a parking lot, the car is very jerky and you have to play the clutch (wearing it out I know) to keep it at the speed i want it to be.

I am going down the road at 45mph, with no problems but once in a while Ill have my foot on the accelerator in a steady position. The car starts to feel like am not even touching the gas pedal. Then ill press it and it will jerk then increase speed. When this happens it is really hard to maintain a steady speed.

This is what I have done so far:

Bled the radiator for any air pockets in the system.
Checked all vacum lines and PCV valve.
I.A.C.V. was switched out with another civics and cleaned.
New Valve cover gasket kit


My next thing is to take out the MAP from the intake manifold. Dremel a line on the rivits so I can unscrew the threaded rivits.

I really dont what to do that since I do not have a check engine light on.

Any suggestions will be appreciated

Thanks for looking.

dmorse88

1) Thread Title

Attention: Poor thread titles have become an increasing problem, which leads to poor forum organization and impossible to find threads (of your topic) in the search engine.

When creating a new thread in this forum, you must select an informative topic-specific title -- for example, not ''i need help'' or ''help me please'' -- so that members browsing thread topics can easily understand your tech problem or question without reading the first post. A good title also helps speed up and increase the number of useful responses by letting members know what precise information is needed.

When creating a new thread, specify in the title exactly what you need help with. ''I need help'' & ''need help asap'' will not suffice. As a matter of fact, it may delay responses or get your thread overlooked or even worse closed. Therefore, your title must clearly state the tech problem or question you have. A few examples of informative thread titles are:

''92 Civic Si: No fuel pump prime or spark after engine swap"

"Stock 99 Civic DX - engine won't crank but starts and runs with a push start"

"93 Del Sol has high and fluctuating idle after replacing throttle body"


----------------------------------------------------------------------------------------------------------------------------
Repeated topics
Before posting a new thread, first search the Honda-Tech site...and also look through the NEW FAQs INDEX.

If you don't find what you need, then please feel free to make a new thread.



As for your problem... Idk.

hyperblu

map or tps sensors...

DCRB

map sensor is just screwed on. the tps is rivited on. before you take sensors off, look up a helms manual and check voltage and what not that you're supposed to do to check tps and map

freddyfingers

bad ecu?

Happened to my 98 civic spent nearly 2 months or more trying to pinpoint the problem. Checked everything possible, finally broke down and took the car to a shop to have them diagnose the problem. After spending $40 all I got was "we think the IACV is faulty". Great I replaced that with a brand new one so the shop got me nowhere. Basically said the ECU wasn't giving them a clear reading "so wanted to install a new one from the dealer for some outrageous amount. They quoted me $1400 total so I just took the car home. Purchased a new/used ECU for $80 cleaned the throttle body again and everything's been fine.


There's a way to reset the ECU as well but cant remember what fuses you need to pull exactly. The fuse box under the hood there's a fuse labeled E/CM I think its a 15 amp fuse. There are 2 15 amp fuse so I just pulled both one rest the ECU and the other resets the interior lighting I believe. You shut the engine off take out the key, pull those 2 fuses wait about 5mins push the fuses back in and start the engine. After letting the car run for 2mins or so the ECU resets and the idle goes back to normal. Thats my only suggestion that worked for me for a few months then would work for a week or a few days once the problem came back. Eventually I replaced the ECU which seemed to be the problem.

Your symptoms are exactly the same as mine though.
"the car revs from 1100rpm to 2100rpm up/down constantly" "hard to maintain a steady speed"

Former User

Please create informative thread titles -- edited.

Clean/adjust the FITV and measure the output voltages of the TPS.

phil_eg_civic

update:

swapped out ecu and theres nothing wrong with the ecu.

TPS tested and its fine.

MR.johnson

FITV.

nasteboyii

if it has just a high idle it is fast idle thermo valve, which in your case it sounds like it revs up and down between 1-2000 rpms, if so thats a idle air control valve, (behind intake manifold) if coolant is low it will affect both previous mentioned sensors

and also haveing a vacuum leak will cause a high idle, but not a rev/up down idle
thats only controled by idle air control valve

hope this helps

pretty common problem among civics i ve replaced dozens on mulitiple cars that i work on

dan