84 T-Type Want Idle

[84TTRegal]

I will tell yall the history of car first

Ok guy's I just recently bought this car from my uncle who had only driven the car about 100 miles in the last 10 years.My uncle bought it from the original owner in 1997 with 42,557 miles on it.

For what ever reason the original owner put a 12 gallon Fuel cell in the trunk
with a large inline can style fuel pump mounted under the trunk.

The car also has some aftermarket computer or what seems to be aftermarket that is Black in color,The injectors have been changed they say 37lb and they are aluminum color.

The guy also put an adjustable wastegate rod on the turbo and no Cat Conv.

When my uncle bought the car he said that it alway's idled ruff and that it took awile for it to warm up and even at 190 degree's it would still idle ruff.

How I ended up with the car is last month when he drove it the car blowed the intake gasket and he didn't want to fix it so he asked me if I wanted to buy it.

So I get the car bring it home start looking over were all the VAC lines and PCV lines go for memory of were they go,but some of the lines weren't hooked up it didn't even have the main VAC line hooked up it was blocked off I look at the break down yall have of the hose's and half the lines weren't even going were they were suppose to be going.

So I go and buy intake gasket, head gasket's, valve cover gasket's,and new VAC lines.

I start taking the top end apart and surprise on the drivers side head the right center head bolt had broke and was just laying on top of the head so the head gasket was blown good thing I decided to go on and do the head gaskets to.

So I debate on getting ARP head bolts,but decide I want to upgrade to some performance stuff later and I will buy them then. So I get the head bolt from my GM dealer.

I put the top end back together put the VAC lines were they are suppose to go the best I could tell according to the breakdown other than the waste gate lines I T'ed them into one line and hooked it up to the turbo.

I start it up and it up it purred like a kitten for 2 seconds then started to fumble I gave it some gas and it was still fumbling until the turbo spooled then it cleared up I let off gas it try's to die pat the gas rev till spool then let off it try's to die.
So I do this for about 5min thinking maybe it needs to warm up,but nothing changed.

No check engine lights came on,but it is a digital dash, but everything seems to work on it.

I know it is running really rich the exhaust fumes are strong.

I do not have away to read the computer so that is out of the question.

I also noticed that I did not see a map sensor anywhere under the hood.
And the Vac Can isn't hooked up.

Also I would like to add I do not have the PCV line that comes out of the passenger side of the intake hooked up cause I didn't think it would bother the engine plus I couldn't tell how they went in the breakdown pic's.

Please someone if you have any suggestions on how to help me get this car running right I will be gratefull.

Please please help me so when I get home today I will have some direction to go with fixing the problem.


Thanks,
Cliff

 

[slow84gn]

i have an 84 gn. the map sensor is on the passenger side on the fender. check there. and gnttype.forum.com i think has a better breakdown of where the vacuum lines hook up. check there its in the tech stuff. good luck
and welcome to the club.

 

[84TTRegal]

Map sensor Location

Slow84 you are talking about the sensor beside the relay's correct?
If so there is know vacum nipple on mine.
I alway's thought that all map sensors had a vacum line going to them.

 

[slow84gn]

the map sensor on my car is on the passenger side next to a couple relays. go to gnttype.org they have sensor locations for tr's. and yes map sensors have a nipple for a hose. map stands for manifold air pressure. hope that helps. mine tees off the port on the manifold on the back of the manifold below the turbo kind of a pain to get to.

 

[84TTRegal]

Map sensor

Slow84 I am a GM parts dealer today I looked into the sensor break down on my car and what I thought might have been the map sensor was ELEK spark Cont module.
It seem's to me who ever my uncle bought the car from didn't have the MAP sensor on it because there is not one.

Also there was not a T for a vacum line going to the passenger side of the car like there is suppose to be there is just one line coming out of the back of the intake going to the Vacum block.

So I am going to go home and overlook the car agian and see if I can find atleast were the MAP eletrical connector is and go from there.

Once I find the MAP connector I will buy a MAP sensor and hopefully this should fix my problem.

This is the pic I see on my GM screen here at work of course it is alot better pic though.

 

[BRAD_PADGETT]

As I recall the MAP sensor on our cars only runs the idiot boost gauge in the dash. You might have a vacuum leak if the MAP sensor is missing. Good luck. Brad

 

[cool 84]

Yes, MAP sensor is only for the boost guage. Digital dash cars only have a switch, no MAP sensor.

You probably have a huge vacuum leak somewhere. PCV not hooked up? There are so many things here... Fuel cell with a big external pump? What type of fuel pressure regulator do you have? A big external pump will overpower the stock regulator and make it run very rich.

 

[tb3]

Some sort of scan tool is going to be a must. you need to find out exactly what numbers the computer is seeing. Getting your tps and iac properly adjusted could make a world of differance with your idle. What about cam sensor? Is it set correctly? You also may want to check into exactly what parts your uncle or original owner put on it. If it has differant computer, injectors.... is the chip correct for them? Is it correct computer? (the 84/5 ECM's are differant than 86/7, its getting more common to change over to the 86/7 ecm's). Also may want to check the MAF sensor. For what its worth... I had a occasional stumble at idle before I had ever tuned my car and was never throwing any codes for it. I converted to a lt1 maf and translator and it has never stumbled since. Checked all your plugs and wires? coil pack? Does it backfire at all?

 

[tb3]

Also, check for air/vac leaks inbetween your MAF sensor and the throttle body. If the car still has the original plastic 90 degree air intake on it that mounts to your MAF sensor, they are prone to crack over time, especially in the flexible "accordian" part of the plastic, making it hard to see the cracks.

 

[84TTRegal]

Finally she is idleing

I finally convinced my wife to help me keep the car running until I can get my hand on the throttle under the hood.

It was the the vacume nipple on the EGR VAC Switch was leaking so I just by passed it .


I was able to get ahold of the original owner he said that he had a cam put in it,but couldn't remember the size that's why it has the ruff idle.
Also he said he had a computer programmed for the cam, injectors,boost,and the Cat being removed.

He said the reasoning for the fuel cell is his exwife put a hole gallon of clorox in the gas tank and it rusted everything inside the tank,but the fuel pump didn't work after she did this so none of the clorox ever passed threw the gas lines or fuel rail.

The fuel pump that was installed is suppose to make the same fuel pressure as factory.It also has factory fuel regulator on it.

He said it is a positraction car that it would run mid 13's consistantly on street tires.

It does have the Digital dash that seems to be working properly.

Thanks for all the help guy's if any of yall are interested in buying the car or know someone please let me know I will let it go for $3,000 wife doesn't want another car in the driveway.

It is all black other than the bumpers with burgandy interior it is a hard top car with power windows that work. It is not a limited it has the nice high back bucket seats. Aslo it is positraction too.

 

[hcox10]

hi
ihave a 84 t type digital dash my booste guauge or rpm does not work please tell me where the switch is at.
thanks harold