93 Civic DX random hard starting

TimHixson

New Member
5+ Year Member
The car is a 93 Civic dx with the 1.5 engine and automatic trans 135k miles.

I bought this for my daughter, and we are having random hard start/no start issues. I did a compression test and all four holes are around 70psi. The problem seems random as it will start perfect one time and then crank like it is out of time next time and be very tough to get going. This is happening with both hot and cold starting. It also happens when it has low gas as well as 3/4 tank.

When ever it is running, it seems fine and drives with no problems. no CEL either.

I have replaced the spark plugs, fuel filter, and checked the air filter. I am heading out to test the icm, and coil, but figured I better ask the people who know these cars the most.

I did a bunch of searches here to try not to waste time on repeated topics.

Any suggestions? I don't want to keep throwing parts at it.

Thanks
 

Blayze2010

5th gen lover
Registered VIP
5+ Year Member
Might be a bad main relay
 


TimHixson

New Member
5+ Year Member
I re-soldered the main relay. I also did the testing on the coil and igniter. All seems good there. The car still has a starting problem. It looks like I am on my way to a new ecu. I don't have another car to swap it out of, so I am looking for a used one. Is ebay the best place to get one? anybody got a connection to get one reasonable?
 


boosted to 26ps

#1 wrecker builder
Registered VIP
5+ Year Member
10+ Year Member
before you swap an ecu and not correct the problem, i would test everything. i would disconnect all the accessory belts first. try starting it a few times to see if you can replicate the problem. might be ps, alt, ac comp going bad causing the hard start. thats if your saying hard start as in its cranking slowly.

if not have you checked the tdc pick up and the crank rotor inside the distributor. swap it with a known working one and retest. a bad sensor there might have that effect...but i would think it would go out and stay out.

either that or check every wiring harness for wear spots, burn throughs, or corroded wiring causing a break to the ecu itself.

doin this first to me seem like a more reliable way of finding out if it actually is the ecu, instead of buying one, plugging it in and finding out it still does this.

on the other hand i do have a ecu laying around for a 1.5 auto.
 

boosted to 26ps

#1 wrecker builder
Registered VIP
5+ Year Member
10+ Year Member
i just saw that....i was sitting here thinking that 70 is really low.... should be around 130-175... i think. but on all 4 cylinders that sir is a bad sign
 

TimHixson

New Member
5+ Year Member
boosted to 26ps said:
before you swap an ecu and not correct the problem, i would test everything. i would disconnect all the accessory belts first. try starting it a few times to see if you can replicate the problem. might be ps, alt, ac comp going bad causing the hard start. thats if your saying hard start as in its cranking slowly.

if not have you checked the tdc pick up and the crank rotor inside the distributor. swap it with a known working one and retest. a bad sensor there might have that effect...but i would think it would go out and stay out.

either that or check every wiring harness for wear spots, burn throughs, or corroded wiring causing a break to the ecu itself.

doin this first to me seem like a more reliable way of finding out if it actually is the ecu, instead of buying one, plugging it in and finding out it still does this.

on the other hand i do have a ecu laying around for a 1.5 auto.
Click to expand...
Thanks, for the advice. I don't have any spare honda parts avaiable to me, so I can only test and buy parts. I ordered the ecu from ebay. It should be here friday or saturday. I got one with a 30 day return policy in case I am wrong.
 

BottleCapBandit

New Member
New to the site and to civics. Not cars. I have a couple ASE certs. but Im having the same problem. Look at the engine light. It will stay illumanted while the hard cranking is occuring. It will go off. You will hear your fuel pump relay click and the pump turn when the light goes off. Then the car will start perfect. I just purchased a 94 civic ex coupe and this problem persist after new relay and ignition switch. It could be ecu related.
 
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