how much affect do engine grounds have on the car

[RobertM]

i know mine are in pretty bad shape and im having issue with the car cutting off at 180 degree...inconsistant idle and cold starts(one day on a cold start it will idle at 800...next day its at 1600) iac seems to be set fine as far as i can tell.i have a scantool but its very old(from 91) the "OTC monitor 2000" hence how i know when its cutting out...so my question is...is it possible the grounds could cause this(the ones that have to relocated due to the factory location)



yea i know i spelt effect wrong...it happens when you type too fast

 

[mikestertwo]

i know mine are in pretty bad shape and im having issue with the car cutting off at 180 degree...inconsistant idle and cold starts(one day on a cold start it will idle at 800...next day its at 1600) iac seems to be set fine as far as i can tell.i have a scantool but its very old(from 91) the "OTC monitor 2000" hence how i know when its cutting out...so my question is...is it possible the grounds could cause this(the ones that have to relocated due to the factory location)


yea i know i spelt effect wrong...it happens when you type too fast

Check for vacuum leaks. You could have a bad O2 sensor. What procedure did you use to set the IAC and throttle position sensor? Are you sure the settings are correct? Is your temperature sensor reading correctly. You could have a bad ignition module if the car is stalling when it gets warm. As far as the grounds go...if they are loose...bad contection...it could cause an issue. As far as the ground locations, they are where they need to be..on the engine. Who told you they need to be relocated? The ground relocation kits are for convenience, not function. There is a reason those grounds are on the engine not somewhere else.

 

[RobertM]

as far as i can tell the o2 is good...still looking for all the vaccum locations....replaced iac with a new factory one...set right as far as i can tell....ive replaced(inhales)o2 sensor with a gnx one...coil and module(old module looked like toothpaste) coolant temp sesnor,swap 3 diffrent maf including one of a picture perfect gn..new plugs and taylors big boy 10.4 wires(dont ask)ive swaped out chips(gnx is current one all my chip are from 1993 or older)now that o2 MAY be bad i had a guy tell me on here to unplug o2 and reset comp(unplug the wire near battery and plug in) but when i did this...in ran with a VERY high idle(2-3k rpms)...i get absolutly no consistant anything with this car right now. at the high idle i dont hear any hissing...as far as spraying the vac lines i gotta find them all first...turbo lines are fine for sure



maybe would help if i responded to the Q...im a car noob...so i had a buddy(gn owner) help me with that...im pretty sure he did it right...Im not sure if this is what he did 100 %..still a car newb getting a crash course.good thing this car has been in my life since ive been alive but never got to work on it until now

 

[RobertM]

i was under the understandign that the location of the grounds would casue the problem to repeat and thus be returning problem....so basicly just replace the grounds where there at for a start..gotcha

 

[mikestertwo]

i was under the understandign that the location of the grounds would casue the problem to repeat and thus be returning problem....so basicly just replace the grounds where there at for a start..gotcha

Just make sure your grounds are tight. It sounds like you are using stock chips. Those things are way outdated. Get a TurboTweak chip programmed for your setup. You will be surprised at the difference it will make.

 

[RmvBfrFlght]

The engine grounds are important, the entire EFI system is grounded there. On EFI cars I see the engine block as the central ground location. The grounds, battery and EFI harness, should not be tied to aluminum such as the intake manifold.

Wire brush the area clean (on CI only) and use some anti-seize on it to prevent corrosion.

RemoveBeforeFlight

 

[TurboBuRick]

The engine grounds are important, the entire EFI system is grounded there. On EFI cars I see the engine block as the central ground location. The grounds, battery and EFI harness, should not be tied to aluminum such as the intake manifold.

RemoveBeforeFlight

I agree accept for part about aluminum. IMO It' fine to use intake bolts as engine grounds.

 

[GNRick]

I agree accept for part about aluminum. IMO It' fine to use intake bolts as engine grounds.

When mechanic installed my transmission, he missed the engine ground that attaches to the block (from the firewall). Car would start but then die out, chug, sputter. I attached the ground strap to the intake manifold and it ran perfect....for about 10 miles. then symptoms returned. Attached the ground strap to where it belonged and no more problems. This has been discussed before....some say attach it to the intake manifold, some say to the block.....kind of interesting that we can't agree on this.

 

[TurboBuRick]

When mechanic installed my transmission, he missed the engine ground that attaches to the block (from the firewall). Car would start but then die out, chug, sputter. I attached the ground strap to the intake manifold and it ran perfect....for about 10 miles. then symptoms returned. Attached the ground strap to where it belonged and no more problems. This has been discussed before....some say attach it to the intake manifold, some say to the block.....kind of interesting that we can't agree on this.

So what do you do when you have aluminum heads? :biggrin:

 

[Steve V]

You make a special long strap and ground it to the motor mount holes at the block.

On the intake...I use the studs for EGR and engine bracket. I move them to the back by the trans dipstick and attach the grounds there. It screws into the head anyways. I also make a jumper from the stud to the coil bracket and the strap from the firewall attaches there also. Done this to many TR's not just my own.

 

[TurboBuRick]

You make a special long strap and ground it to the motor mount holes at the block.

You guys crack me up! Did you make a jumper strap to the headers too?

 

[RobertM]

CI??? what that...

 

[Phoneguy]

You make a special long strap and ground it to the motor mount holes at the block.

On the intake...I use the studs for EGR and engine bracket. I move them to the back by the trans dipstick and attach the grounds there. It screws into the head anyways. I also make a jumper from the stud to the coil bracket and the strap from the firewall attaches there also. Done this to many TR's not just my own.

Aluminum is a much better conductor than iron.

Bryan

 

[RobertM]

Just make sure your grounds are tight. It sounds like you are using stock chips. Those things are way outdated. Get a TurboTweak chip programmed for your setup. You will be surprised at the difference it will make.

its gnx chip from 1991..

 

[TurboDave]

You make a special long strap and ground it to the motor mount holes at the block.

On the intake...I use the studs for EGR and engine bracket. I move them to the back by the trans dipstick and attach the grounds there. It screws into the head anyways. I also make a jumper from the stud to the coil bracket and the strap from the firewall attaches there also. Done this to many TR's not just my own.

I didn't go quite that crazy, but I do have the Casper's ground stretcher kit. I ran one braded line to the rear intake bolt, and another to a bell housing bolt that goes into the block, so it's a good central ground point now. I also ran a wire from that into the cabln and is hooked into my auxilliary fuse block, adding a good engine ground point inside the cabin.

 

[motorhead]

its gnx chip from 1991..

Didn't they call those chips "the grenade chip" when they were new and gas was good? Something about staying in it longer than 14 seconds and grenading your motor?

 

[EVIL]

If you connect the ground to the intake bolt and the intake bolt connects to the head, isn't that an all steel connection?

D

 

[RobertM]

Didn't they call those chips "the grenade chip" when they were new and gas was good? Something about staying in it longer than 14 seconds and grenading your motor?

out of the 5 i have it works the best...the stock one look pretty beat up so i wont install it,pitbull is bad,reds are too hot... so..yea. i need to oreder i new one...just tring to get all the little bugs fixed...

 

[DailyDrifter]

You say the car cuts off at 180, is that number being read from the scantool or aftermarket gauge? Bad grounds defiantly cause problems. Bad coolant temp sensors can also cause problems, as the ECU determines how much fuel to add to a given coolant temp.

 

[RobertM]

You say the car cuts off at 180, is that number being read from the scantool or aftermarket gauge? Bad grounds defiantly cause problems. Bad coolant temp sensors can also cause problems, as the ECU determines how much fuel to add to a given coolant temp.

i have a very old school "otc monotor 2000" the plugs into the......thingie alcs i think its called...its showing around 180 degree its begins to stalll....iac increases with the rpm drop....tps seems fine....i did a naughty thing when i replaced coolant temp sensor...i went to napa...so i may need to order 1....im starting to get a little consistancy....this is WELL into closed...i can get it to refire when the temps drop below 180...weird aint it... i wacthed the volts on the o2 the seemed a little jumpy...whats the iac suppose to be at its started at 175...then droped to 65 then would rise when the car would try to stall...02 sensor was replaced ith a gnx one...but it was a new one.im not sure if its the pesky one that goes bad alot