Is it a short or a computer problem?

[JeanDSM]

Ive been having electrical problems for about 4-5 months. I cant even drive my car. Right now i dont have dsmlink on my car cus i burned the ecu, (still havent fixed it). Put back my 97 stock ecu and MAFT to 880 cc and all that.

I installed a new alternator and two new batteries.
This is the problem....

When I put the ign switch on, My apex TT volt meter reads 11.4~11.6v

I start the car...

Horrible idle, can even keep my engine running alone at idle. I have to rev it.

After the car is on the meter reads 10.2 ~ 10.3v

If i hit the accel pedal WOT the rcar reach a max rpm of 3500rpm ~ 5000rpm and the car makes crazy sounds like poping sounds, like a pop corn machine inside the Intake manifold, i even hear it from the turbo intake pipe, looks like im going to break the engine

If the car is over 3.5K rpm the volts are over 13.2v to 13.4v

If i release the the pedal the car lose volts and the engine stops.

Theres no short between the battery in the trunk to the fuse box. New battery, New Alt dont know what to do.

 

[Black91TSiAWD]

have you cleaned the maf lately?

I guess those things are pretty touchy.


And if you know any other dsm's, try having them put your ecu in their car and see if it does the same thing.

 

[poonman]

I'm thinking it sounds like a short of some type, if your voltage's are becoming unstable along with the popcorn noise, maybe try thinking about your timing, almost like you have a sensor short making the timing to become retard or advanced. I'm not the expert on this but sharing my insight.

 

[JeanDSM]

have you cleaned the maf lately?

I guess those things are pretty touchy.


And if you know any other dsm's, try having them put your ecu in their car and see if it does the same thing.

I tested the Translator box and the GM Sensor on a friends GST and worked great on theis car. But i havent tested the ECU.

 

[JeanDSM]

I'm thinking it sounds like a short of some type, if your voltage's are becoming unstable along with the popcorn noise, maybe try thinking about your timing, almost like you have a sensor short making the timing to become retard or advanced. I'm not the expert on this but sharing my insight.

I changed my spark plugs, spark plug cables, Coils, and tested a friends power transitor, still have the problem.

I stripped the engine harness the best i could under the hood, cable by cable if there was a broken or bad cable and everything looked good. I tried to do it under the dash but it is very dificult,

is there a better way how to find a short?

 

[luv2rallye]

is there a better way how to find a short?

http://www.dsmtuners.com/forums/showthread.php?p=1496998#post1496998

Also make sure your Alt fuse is ok and you have good clean tight grounds to engine and frame.

 

[poonman]

I changed my spark plugs, spark plug cables, Coils, and tested a friends power transitor, still have the problem.

I stripped the engine harness the best i could under the hood, cable by cable if there was a broken or bad cable and everything looked good. I tried to do it under the dash but it is very dificult,

is there a better way how to find a short?

Just get a multimeter, put it on ohms,plug one cable into the beginning of the wire and the other cable in the end of the wire, if it zeros out then you have a solid connection, but ony after the shake test, once multimeter is connected to beginning and end of wire just shake the lead around anywhere you can grab it to make sure, once done that, turn the key on and do it again.

 

[TALONTRAX]

Ok man, here`s what happened to me on my 2G, ONLY after an ecu swap(95 eprom w/custom chip) . . .

Swapped in the eprom ecu, car ran like crap, & sometimes would not start at all. I assumed that it was a bad ecu or chip(the car ran perfect before the swap).

After 3 ecu`s, 2 chips, & 2 months of testing components(mas,ignition transistor,tps,etc.), The problem was a bad main ecu & sensor ground, behind the dash, where the black ground wires break out of the main ecu harness, & bolt down to a metal lug with a 10 mm. nut on the metal inner dashboard support.

What happened was, the 4 or 5 ground wires terminate at a ring terminal, which is bolted to the dash frame for a gound, The FACTORY crimp was bad, & by disturbing it (swapping the ecu, & jostling the ecu harness wiring),the weak crimp failed, leaving the ecu & all sensors with no or limited ground paths.

This drove me freaking nuts for weeks, until I started tracing wires & found it.
Check your ground harness dude . . .