vtec_powah

i just swapped my 1990 civic dx engine for a 1992 civic si block and head, everything else is 1990 civic dx, and the car starts but the engine is always reving at 20 km per hour for about 5 seconds then it slows down at then it does it again, it does this aslong as the car is on, but what i dont under stand is when it does this the car is in neutral, and when i put it in gear, the speedometer goes higher, does anyone know whats wrong with the car??

5gen-hybrid

sounds like a vacuume leak

samdawgsol

the speedometer or rpm one(forgot name of it sorry) is surging up and down?

vtec_powah

its the speedometer going up and down, i also check the ecu (flashing led), and it flashed 16 times, i checked the civic shop manual, and it says that 16 flashes is the fuel injector

BreakStuff

First off check the coolant level.. if the coolant is low the coolant temp sensor will throw an improper reading and the ecu will "hunt" for the proper idle speed..
The intake air temp sensor will do the same thing if its values are off..
Did you change intake manifolds as well?

and BTW...the Fuel injector is most likely not the culprit here..


[Modified by BreakStuff, 3:56 AM 8/7/2001]

Jay Slugg

I had this same issue when I changed from a more powerful engien. I found that it was the censors that were causing the issue. I had to find compadable censors to get it to run correctly. The worst problem was the Trans. The Trans worked but when changeing gears the engien wold rev and pop the gears. I replaced the ogagin censor even though they said I did not need to. The other suggestion at the time was to get the problem reprogramed. The problem turned out to be the computers that the car used to operat everything. I replaced my 1992 Civic with a small block v6. Only mod was the bell houseing to make it fit onto the Trans. I first though it was the problem. But then again every problem is unique and well the fun part is figureing it out. the bad part is the time between finding the problem and the solution. Good luck hope I have helped.

vtec_powah

nope i didnt change the intake manifold, im still using the one from the 1.5

BreakStuff

ok, On the throttle body assembly , just located below the cover that says "PGMFI" you will see 2 fuel injectors that go into the base of the throttle body.. both the injectors have a 2 pin connector..make sure the you have the "green" connector on the lower fuel injector and the "brown" connector on the upper fuel injector..
( switching these connectors around is an old Honda tech "prank" used to screw up other techs after doing a head job/motor swap etc..)

Other than that, i would look to see if you had a leak on the intake manifold gasket, start the car and get it to start "surging".. when it surges, spray some carb cleaner directly on the intake gasket and see if the surging goes away..

Make sure all the intake manifold nuts are tight, this is pretty easy task using a 12mm wrench, and you shouldn't have a problem accessing them form underneath the hood..
Let me know how ya make out... GL