Turblow

I just bought a 90 Civic Dx with a b16a motor (1st gen I believe since its running an OBDO pr3 ecu) and it has a problem starting
The first 2 tries itll pretty much just keep cranking, then maybe it will kick over run for 1/2 second then die, try again and itll run for 4 seconds, rumble then die, and again til it finally stays running on maybe the 6-10th try

I havent had time to diagnose or really go over anything mechanical on the car yet But Im hoping this is an easy fix as I want the car to be my daily driver after I get finished with the body work in a few days

The only thing I noticed that is definetely wrong. There is a sensor on the left side of the head (passenger side) under the distributor and closest the the front of the car. Its a gold fitting screwing into the block, probably supposed to have wires connected to it (theres a few wires by the tranny taped together that I think dont lead anywhere). So I dont know what that sensor is yet but that could be causing it I suppose


The car doesnt have a tach so I dont know what RPM im revving to and Ive never had a Vtec motor before but I dont think vtec is working either. The car has a bad wheel bearing that I need to get fixed before I really beat on it.

Im hoping I can still pass emissions
Any help is appreciated

Thanks for any help

Zeniceguycrx

could be a coolant temp sending sensor in the head

Turblow

My guage reads normal and moves so I dont think thats what it is

punkracer

check the wirring maybe a poorconnecton was done when doign the DPFI-MPFI conversion...aka plastic butt conectors if so soder them up.... ANY CEL's ? Check your grounds. look near the thermostat thats the main ECU ground.

theres two or three temp sensors on the engine on goes to the ecu one goes to the gauge and sometimes on is there to operate the cooling fan.

punkracer

also check your fuel pressure might have a weak pump.....look for about 35psi and 45psi @ WOT

Zeniceguycrx

there is one sensor for the gauge, 1 wire. and there is another gauge 2 wire for the coolant temp sending sensor


you car runs ok once its warm right?
if so its that sensor

Turblow

Since Ive filled it with gas its started first shot everytime I tried

I'll try in the morning, it might just be when its been sitting for a while

No codes, Grounds are mint and new.

Still unsure what the sensor I mentioned is broken could be, or if I need to fix it

JDMFantasy2K

pics would be helpful. But they have 3 sensors, the one wire in the head is for the gauge, then there's one on the thermostat housing ( i believe that's the actual ECT the computer sees) and then the one on the front side of the head (i believe that one is for the fan).

Sounds like there may be more going on than you realize. Are you sure the motor is mechanically sound? How does it idle when it does run?

88crxSi

thats for obd1+

obd-0 has the temp sensor for the rad fans on the back of the block near the oil psi sensor.
the two under the dist are for 1. the temp guage on the cluster and 2. for the ECU cold engine compensation. I believe neither are causing this issue and its a bum main relay, listen for the clicks (corresponding w/ the Check engine light coming on when you turn the key to ON).

Turblow

I TRIED to check TPS voltage but was unsucessful

I used the middle red wire to take my reading from (pretty sure thats right) and with the ignition kicked over I wasnt getting any reading, had a beautiful piece of spliced wire to touch but no reading, so I turned the car ON and took a reading and was getting fluxuating results that were just kinda scatterred

So whats up with that

I also have 10+ main relays I pulled from the junkyard out of regular ef hatchs so I suppose I could try a new one of those

The check engine light does not come on when the fuel pump is priming though

So is the sensor thats missing the wires important? How would I go about reattaching the wires into the sensor when there broken off(probably ripped out) of the side of the head