rotary_yankee

How do you ground the ecu?
Is it true that instead of grounding the boost sensor its better of ground the ecu because the ecu hold the ground for boost sensor,tps,afm and the ground under the UIM.

I'm having the hesitation problem at the 3800 rpm. Í've ground the motor with a 2 guage wire and ground the chassis with an 8 guage wire. and the ground located on the tranny to the firewall. And I still got the 3800 rpm hesitation. I replace the tps , boost sensor , and i have a fcd.

The hesitation come hard when I press the gas pedal all the way down (full throttle). so I search on the forum and I was wondering if ground the ecu would help or should i get another harness? when i'm in neutral it rev fine but in gear it has hesitation. and hesitation start to happen when the car gets warm up. if i restart the car again it goes away for a little while (3-4 minutes) then it come back.

thank

gxl turbo 2 conversion
fcd
greddy fmic
255 walbro fuel pump
rb exhaust and dp 3inch all the way
remove all emission
rebuilt motor about 150 miles on it
custom intake
no ac ps

--MAstermind--

sounds like my prob almost i am gunna change my plugs and im going to get a new temp sensor...i think i fouled out my plugs running rich....BUT...lets see...also my O2 sensor is shot we shall see what happends.....good luck post up anything u may find so i can try them out as well...also search for the seafoam water injection mod....

rotary_yankee

my o2 sensor is not even connected. but that would cause the problem (i think)

HAILERS

The ECU grounds are on TOP OF THE REAR ROTOR HOUSING on top of a boss and held down with a bolt. There are two (2) wires on that ring terminal. The wires are BLACK. Both are BLACK. They are a part of the EMISSIONS HARNESS.

Those wires leave the ECU (just like you read in the fsm) on pins 3G, 2R and 3A. the 2R and 3A are spliced together before the wires reach Ground Terminal 24 (picture in the fsm).

The wire that runs from just inboard of the wiper area to the engine is NOT A ECU wire. Just run that wire from the area of the wiper motor to anywhere you darn well please on the engine. Run it to the intake manifold if it's easier.

I took everything I wrote above out of the 87FSM. The 88 is very similar. Very.

If you look at the wiring diagrams, the EGI and Emission System you'll see the three wires. On a 88 model the ground point is not called Ground Point 24, but is located in the same place, ON TOP OF THE REAR ROTOR HOUSING. Not on the rear side housing but ON TOP OF THE REAR ROTOR HOUSING on a boss.

I jpg'd a picute recently of a rear rotor housing and the boss. It's out there somewhere.

If you have actually checked the ECU ground on the rear rotor housing and you KNOW it is good and the wires at the pins 2R, 3A, 3G on the plugs, all read around .3ohm with the key to OFF you might try splicing another ground wire of your own to those three and try grounding it at the ECU mount attach studs.

The early 86-87 had a ground problem with the AFM so they added a ground wire to the boost sensors brown/black wire and terminated it at the thermostat housing. Note the years stated. Later cars shouldn't have that problem.

And you know that all the sensor brown/black ground wires on the Emissions harness are mechanically spliced together inside that harness and go to pin 2C and by hook or crook to the ECU ground wires 3A, 2R and 3G.