RobertoHdz

Hey guys I'm wondering if y'all could help me diagnose my car I have a 92 civic si I went to start it this morning and it would crank, rev up and turn right off. After about 20 tries it finally started but it was idling horrible and my exhaust was sputtering, got to the first red light and when I went to take off I wouldn't go anywhere until I got up to 3rpm, so I just went back home and parked it because I had to go to work. Any ideas?!

mk378

Look for ignition problems like wires came off or a cracked distributor cap. Running the engine in the dark can show if sparks are jumping outside.

Then I'd start by pulling the fuel injector plugs one at a time to see if running on all 4 cylinders. Also check mechanical timing.

All this is assuming the check engine light is not on. If it is on, pull the code.

RobertoHdz

So I ran the codes and it brought up the tps and map sensor so I changed those but now it will crank rev up to 1k and shut right off. I changed the fuel filter to see if maybe it was plugged up but still the same now i can't even get it to run.

mk378

Make sure the MAP and TPS plugs aren't swapped. The plug with a solid white wire goes on the MAP.

RobertoHdz

They're not I did them a couple days apart because I had to order the map so that shouldnt be the issue thanks though

RobertoHdz

So I changed the distributor cap and rotor and it turns on now and runs better. The only thing is now though is that when I turn the key I have to hold it for a couple of seconds and throttle the gas pedal for it to start when it's cold. Any ideas?

mk378

TPS out of calibration or IACV stuck/clogged.

RobertoHdz

Man I cleaned the iacv it's still doing the same thing. How do you Cal the throttle sensor ? Just an update on it its got new fuel pump, pump relay, distributor cap and rotor, fuel filter, map and tps. Im going crazy right now!!

sumdewd

Have you checked the resistance on the plug wires? And how are the spark plugs doing? Compression test? Is the throttle body and plate clean? Have you explored any possible vacuum leaks? You've done a lot, but haven't found the exact issue yet. Keep on it.

I would also bench test the resistances on the igniter unit and ignition coil. I have replaced both the igniter (Ignition control module) and coils on ALL of the older Hondas in my family in the last 2-3 years. The 90 Integra coil I had read resistance in the millions. My 90 Si HB's coil literally fell apart, crapped out debris which then snapped my distributor cap when it hit the rotor. My Civic's igniter unit also got heat sensitive in 2015 and stranded me twice. Your mileage may vary.

The TPS is not serviceable by normal means. You need to kind of hacksaw the old rivets (Screws with rivet heads) out, then buy new screws with allen-head keys. The TPS is then adjusted by loosening the mounting screws, measuring the voltage with ECU on, and twisting it to the correct angle. It's something like .45-.5v closed, and 4.5v WOT. Don't quote me on exact numbers--a service manual page exists somewhere for the correct voltage reading. Keep in mind there's a gasket on that TPS. I made a crude gasket out of a sheet of gasket material and an exacto knife.

RobertoHdz

Okay thanks i will look into that. Just another tid bit of info when at idle it goes up and down and also I was slowly going up to 3rpm and my exhaust was sputtering idk if thats an indication of anything?

sumdewd

Up and down idle is usually a vacuum leak, however, the 4th generation had a bad batch of igniter units that would cause hunting idle. I'm not sure if that would carry over into the 5th gens. A hunting idle can also be an improperly set idle screw. The IACV tries to correct but it's just too far out of range. Be sure to follow the idle set/learn procedure in the service manual properly to eliminate another possibility.

Sputtering is still a good indication you're not running well for some reason.

Just keep in mind you need air, fuel, spark, and compression. Your car is missing something from one of those areas.

RobertoHdz

Hey guys I just thought of something. I think my ECM is bad could that have anything to do with my problems ?

sumdewd

It's entirely possible, but you're delving into a more exotic cause. You could pull the carpet back and verify it's the correct ECU for the engine, though. That wouldn't hurt anything.

RobertoHdz

So update I finally figured out what was wrong with me car. I feel kinda stupid but oh well it's a learning process. So it was the spark plugs 😑 yeah I know probably should've checked those first but eh what are you gonna do. At least my car got a nice tune up out of it lol. Thanks everyone for your help. Now if I can get the lighting in my car to work that'll be great 😂

sumdewd

Easiest and free/cheapest things first. It probably only ran you like 12 bucks. Good to hear it's fixed. You should start another thread on the lighting issues. HT is a great resource.