DDEC III and IV repair tips.

[sptecnico82]

OK... Cummins haves its own thread about repairing... why don't we start a thread about repairing Detroit Diesel ECMs too?

There are many people who knows many tricks.... we can share about that.

[ddmech]

Thats because cummins has about 60% failure rate.Ddec probably 5%.

[sptecnico82]

Thats because cummins has about 60% failure rate.Ddec probably 5%.

You are right.... but in my country there are 4 DD for each Cummins.... thats why I see many DD damaged.

Just for introduce a topic... what is the function of each 32 pins chip that store the program?. There are 2 that say "FLASH", 1 with a sticker and another that I dont remember what says.

I suspect that the 2 that say "FLASH" are the volatile memory. It is?

I hope somebody can know the answer.

[Matrans]

anyone know anything about the timing on a 14LTR DDEC IV was told if you advance it up 1 tooth gives 30-40 more HP at the wheels

[sptecnico82]

anyone know anything about the timing on a 14LTR DDEC IV was told if you advance it up 1 tooth gives 30-40 more HP at the wheels

I dont belive it can be done that way.... maybe with DCT is better.

I saw a engine with one tooth timing of mistake and it cant stay run.

[Matrans]

Have already used DCT but always looking for more.Was told of a Mechanic that works for Detroit he has done it and dyno report before was 580hp after was 616hp at the wheels.

[sptecnico82]

Have already used DCT but always looking for more.Was told of a Mechanic that works for Detroit he has done it and dyno report before was 580hp after was 616hp at the wheels.

Very interesting.... if we can know more details... maybe somebody can try with an engine..

[ddmech]

we advance timing frequently on ddec iv.You check timing with gauges to find present timing.One tooth will advance app .40 injector lift.Some motors will stand it and some wont.YOU MUST CHECK TIMING FIRST WITH GAUGES.VERY CRITICAL THIS BE DONE.If not disaster is posible,he,he,he!

[sptecnico82]

we advance timing frequently on ddec iv.You check timing with gauges to find present timing.One tooth will advance app .40 injector lift.Some motors will stand it and some wont.YOU MUST CHECK TIMING FIRST WITH GAUGES.VERY CRITICAL THIS BE DONE.If not disaster is posible,he,he,he!

Can you make a more detailed explanation of the process?. I am not a mechanic.

[torqueman]

I don't think that chnaging one gear teeth will chnage hp in any case.Done tones of inframe and never seen or heard if anybody have done one teeth advanced and engine still running normal.

In my case by change i have done one teeth wrong while installing cam shaft on 04 egr dd engine and after everyhting done, Started engine, that runs like a shit,smoke everywhere,vey hard to start.

These are not mechanical engine that you can advance or retard engine timing and getting more power.
I don; t agree with that.

[Matrans]

we advance timing frequently on ddec iv.You check timing with gauges to find present timing.One tooth will advance app .40 injector lift.Some motors will stand it and some wont.YOU MUST CHECK TIMING FIRST WITH GAUGES.VERY CRITICAL THIS BE DONE.If not disaster is posible,he,he,he!

Yes you are right,we checked timing and it was at 275 if advanced it would take it up over 300 to much.A bloke told me Detroit specs are (254-299) Was told if it was under 260 no problem but not at 275.

[ddmech]

275 is low average.You can go .05 to .10 over specs without damage to engine but you must watch ex temp in warmer weather.Will run like scalded dog!

[amishmafia00]

search on forums for detroit power service literature (psl) i believe this has the entire series 60 manual in it. it will explain exactly how to check your cam timing

[dieselman77]

Question for you Detroit guys : have a 1999 ddec III or IV engine i think its III but for some reason the cooling fan will not shut off I plug into the thing and it says aux switch is grounded buy there is no switch in the cab so what exactly does that mean ? and where can i find the switch to test it ? thank you

[amishmafia00]

if you have an ac pressure switch disconnected or faulty it will make the fan run. i forget how it's wired but the systam thinks that the ac pressure is high so it runs the fan to try to bring pressure down by cooling the condenser