1G Leaking ECU caps cause hard or no start?

[16g-2ndgen]

when my car has sat for more than 5 hours, its very difficult to start. it has the symptoms of a bad tempature sensor, so i replaced that and fixed the corroded wires to that connector and still nothing, then i replaced the throttle body with all new sensors and still no fix. so i pull my ecu and in the middle between the two wall chip things, under the bigger of the two black caps, theres a nice burn mark. could my ecu caps leaking cause a hard start? i just dont get how my car will start right up after its running.

 

[360glitch]

Leaking caps can cause all sorts of issues. It definitely needs to be fixed as soon as you can. May I ask what are your hard/no start symptoms?

 

[16g-2ndgen]

Leaking caps can cause all sorts of issues. It definitely needs to be fixed as soon as you can. May I ask what are your hard/no start symptoms?

im locating an ecu as we speak .. stupid 1990 dsm's .

it just turns over dead for like 30 minutes, then after trying more it will just turn over and start firing and wont start.. then it will kinda run.. then die and i hear backfires coming out the intake. then after about 45- hour of trying it will start and run fine, with wierd idle and mediocore misfire.

 

[Andrew7DG]

Depending on the damage and if you feel confident, you can replace them yourself. I think you can buy them off of ebay for $5. Or if you just want to buy another ecu that work also. Can I buy your old one then?

I did mine and it was pretty simple. Sometimes leaky caps causes fuel pump problems. Can you hear your fuel pump start up?

 

[bvass]

You can also send your ECU to ECMTunning to get fixed. They fixed my capacitor caps for $36.

 

[ekanddsm]

My caps went bad and I would misfire for no reason while cruisn down the road.

 

[resilva]

Your best bet is to send it to steve here on this board. He does top notch work at very reasonable prices.

I don't see the point in buying a used ECU that can go at anytime. You can get your original one repaired to as good as new, for the same price or less as a used one.

My ECU was completely dead. I recently sent my 1G ECU to Steve who replaced all my caps, fixed the damaged traces on the board that the leaking caps had burned through and even socketed my ECU since it's a EPROM ECU.

He charged me $135 to repair and socket my ECU, luckily my board wasn't severely damaged.

The quality of the work is of the highest quality; extremely professionally done.
My ECU is as good as new.

I don't think people on this board realize Steve does amazing ECU repair work.

He's been bringing back to life dead ECUs for DSMs and the Stealth/3000GT guys for years, very reputable.

Here's a link to his site http://simon.chi.il.us/ECU/

-Richard Silva-
'93 Talon TSi
O.G. Socal Club DSM

 

[steve]

So i pull my ecu and in the middle between the two wall chip things, under the bigger of the two black caps, theres a nice burn mark. could my ecu caps leaking cause a hard start?

I forget what the GVR4 boost gauge does on startup but if you don't see a CEL for five seconds when you first turn the ignition on then the ECU didn't power up correctly. On turbo DSM's you also get the boost gauge going to 0 until you start cranking the engine.

The capacitors that leak are filters for the power to the computer. Once they go bad the leaking electrolyte can cause shorts, and eat up the circuits on the board, and allow electrical noise to crash the ECU. Just changing the caps at this point isn't likely to fix the ECU. It's going to need more work to become reliable again. The original GVR4 ECUs were all EPROM versions so it's worth trying to have it repaired before trashing it.

Anybody who still has original capacitors in their ECU is living on borrowed time.

Richard thank you for the kind words.

 

[tsi1991awd]

I have a problem similar to this. When the car sits for 8+ hours, it will be really hard to start. It will just crank and crank and crank but takes 3-5 minutes before it will fire up. When it finally fires up, it will idle for 2 seconds then die. Fire it up again and it will do the same. So I have to keep my foot on the gas for about 10 seconds and after that it'll idle fine.

I ordered some caps...I have no clue when they were replaced, if ever. Hopefully it's not too late to fix. Hell, that might not even be my problem.

But the thing is, if I go out to the car say....after 5 hours, the car will start right up. It's strange. No fuel pressure issue, CTS is fine, wires are fine, etc. etc.

 

[steve]

A key point I'm trying to make here is watch the CEL and boost gauge when you turn the ignition on.
If it doesn't do what I described then the ECU isn't running and nothing interesting is going to happen when you crank it.

 

[tsi1991awd]

So are you saying that if the boost gauge goes to 0 and the CEL is on then goes off then the caps are fine? Because my gauges are normal but.......

 

[steve]

So are you saying that if the boost gauge goes to 0 and the CEL is on then goes off then the caps are fine? Because my gauges are normal but.......

No that's not what I said was it. All I said was that if those don't happen then the ECU isn't running. There are plenty of other things that can be wrong. I've seen many an ECU with bad caps that would power up and start the car but run poorly until something critical failed.

 

[tsi1991awd]

No that's not what I said was it. All I said was that if those don't happen then the ECU isn't running. There are plenty of other things that can be wrong. I've seen many an ECU with bad caps that would power up and start the car but run poorly until something critical failed.

Sorry, I misunderstood. Thanks for clarifying. I have the caps on the way from Digikey so hopefully they show up next week. Hopefully this fixes my hard start. I read in a post of yours from a little while back - you said to neutralize the electrolyte if it leaked....what would be used to neutralize it? And also, how would you go above removing any corrosion?

 

[16g-2ndgen]

sorry steve, i should have clarrified better. this isnt the ecu on my galant, but the ecu on one of my talons. its a 1990 non eprom. I

 

[16g-2ndgen]

thanks for the replies, and i will check that thing steve! Oh i should have clarrified, the ecu isnt out of my vr4, but its out of my 1990 awd, and its non eprom. i think the gauge went to zero but i cant remember. can you pm me your prices and how long will it take to have you rebuild it? can i take pictures of the burns to make sure its salvageable.

 

[16g-2ndgen]

ok update:

i just got a great condition 90 tsi ecu that im borrowing to test out my issues.. even with the ecu swap still no ####ing start. since i had an extra tempature sensor sitting around i unplugged the wires from the one in the therm. housing and i plugged it up to the extra one, that i had sat in a cup of 190-200* water.. and after that still no start.. whats next? what should i look for?

 

[steve]

If your sure that the ECU is running then it's time to follow the check list for no starts.

http://www.dsmtuners.com/forums/articles-miscellaneous/217951-how-diagnose-no-start.html