Did you have it tuned?

 

No, it was my understanding that it shouldn't have to be tuned because I was purchasing a complete kit in which the components are supposed to work harmoniously. Also it was my understanding that by converting the car to mass airflow the computer would automatically compensate for any changes to fuel delivery and airflow.

 

it SHOULD work okay without a tune, although a tune would help. there are many other things that could mess with an idle : vacuum leak, tps, idle set screw, maf setup wrong, the list goes on....its hard to diagnose without specifics

 

The TPS isn't even a year old, there was a vacuum leak at the throttle body until this morning. That leak was causing really high idle (1500 rpm). Turns out that the throttle body was a defective part. I had summit overnight me a new one and now I know for sure there isn't a vacuum leak, but the car still won't idle right.

If it ends up needing a tune, does anyone know of anywhere in Chicago where I should have it tuned, and also how much that costs?

Why did I even bother converting this car to mass air if I could have just kept speed density and have the computer flashed with a custom tune for my setup???

 

because maf is a more adaptable system

 

i would start with vac leaks, if ya still got the plastic lines nows the time to put on some rubber ones. make sure to check all you vac line not just the ones by the t.b.(since a shop worked on it you never know what they disconnected)

tps sensor check
.98 volts(this one is my guess)

clean the iac

check your timing( bump in not alredy done)

lower the fuel pressure,

these should help but also i never had to do a maf conversion so it could be with that

 

Something isn't right... you don't need a tune what so ever. You should be able to slap that kit on and go across country.

Check everything from plugs, firing order, is the maf calibrated for the injectors. Play with the idle screw and get the most vacuum possible out of idel, weres the timing at?

 

Have the shop stand behind there work.

If your at the point where you dont trust them, Start running through the lists posted above.

 

What computer, what brand MAF? If it's some cheap one with sample tubes, try clocking it. The BBK cai has a bend in front of the sensor, sometimes those tube ones don't like it.

Was the MAF conversion made before or at the same time? When i changed another MAF it took a while for the computer to "learn" the new MAF, during that time it wouldn't idle for ****. After about 20 miles of driving it was fine.

 

big question is did you change your computer?? if not there is 100% of your problem.

if you did then disconnect all your vaccumes coming off the intake and only hook up the break booster line, the fuel pressure regulator line, and your pcv, take everything else out of the equasion for now.

double check you have a vaccume going to your fuel pressure regulator.

lets do a base set up here.

check your fireing order (remember to use the ho fireing order) 1-3-7-2-6-5-4-8

when the #1 cylender is at TDC (COMPRESSION STROKE) then the dizzy on the distrubiter should be pointing almost stright back

1-get the car running
2-pull the spout out of the distrubitor harness
3-loosen the distrubiter bolt
4-time it to 10* (use a dial advance timing light and time it to tdc on the balencer)
5-go to the tps and there are 3 wires coming out i believe its the green wire should have .98v +/- .2v (use a volt meter) (if u dont have one buy one u cheap ass)
6-pull vac off fuel regulator, fuel pressure should be at 38 with the vac off then reinstall vac line
7-adjust your idle screw to prefferred idle


if all this fails i would do a leakdown test.

 

that was way too much to type

 

Also spraying carb cleaner is a simple way to find vacuum leaks. While the car is running spray around your hoses, intake gaskets and throttle body gaskets. If it revs up all of a sudden you have a pretty good idea where the leak is at.

 

Like mentioned above, if you still have the da1 computer which is speed density then you have a problem. That needs to be switched to a maf one and also a tune would help smooth things out but your idle shouldn't be that bad right now. How bad is your idle exactly? also take note that you no longer have a stock cam so your idle/vacuum will be different from when your car was stock.

 

The shop could have re pinned the SD computer and there is a possibility of error with that too.

 

I'm sorry I should have mentioned as well that the vacuum lines were all changed. We already went through that one. hahaha I also should have mentioned that I DO have the A9L computer. When I said I converted it to Mass Air I assumed that it was automatically understood that the A9L computer was part of that conversion.


I just called the shop and here's the situation. The fuel pressure is set to 40 PSI. The car does start and it does run. Again, there are NO vacuum leaks. It idles at 1,000 rpm and it lopes down to 700. While it's loping the engine is laboring as the car is vibrating and shaking a bit.

 

what brand MAF is it ? calibration could be off by just a little and throw it off big time at idle

30lbs injectors are a little big for the combo ....possibly aggrivating the situation , was the vacuum line on or off when you adjusted the fuel pressure , It should be off and plugged while adjusting it to 38-39 psi , and when hooked back up you should be at 32-34 depending on the amount of vacuum you are pulling

Best thing I have found on these cars is to get a 93 cobra MAF and 24s and burn a chip using the A9L starting file but with 24lb injector slope and 93 cobra MAF transfer and the car will run like a dream ......

 

I know I am comparing apples to oranges here, but I have seen some cars have a problem about idling up and down when the cooling system has air in it or it hasn't been bled.

 

chances are they cant keep it idling long enough for it to get hot LOL

 

It's a summit brand MAF sensor. 30 lb per hour so it does match the injectors. It's also the one that's calibrated for having a CAI since I have the fenderwall intake setup.

 

Did you install a new harmonic balancer , if not the timing marks could be off if the outer ring spun on the old balancer ....that could cause problems as well

 

my car ran fine without a tune and 24lb injectors, i thinks you got too much injector without a tune

 

I have a track heat top end.During the summer I keep the a/c wide open so I idle my car at 11-1200rpms.What rpm are you trying to idle at?Your cam may not let you idle at 800rpms.Just a thought.

 

no the tfs 1 cam will idle that low, had it in my car

 

Mine will idle down to 800 but it has too much lope to it.When I would come to a stop,it was bad about wanting to shut off.Anyway with it idled up a bit it helps to hide the cam.lol

 

No there isn't a new harmonic balancer on it. When the car was SD I had it idling at 900 rpm most of the time. So I'd be happy with that as long as it wasn't loping and shaking.

 

the throttle position sensor needs to be at .92-.98 volts with the engine running as well ....so make sure when you adjust the idle screw you dont go over that reading with the TPS

 

My TFS 1 will idle at 850 but is much smoother at around 950 rpm.

Maf tunes are hit or miss.. They def don't help with idle situations.

 

no but it still idled fine in 115 degree weather

 

Good for you,still don't sound stock.Not trying to get in a pissing match with you,discretion is the better part of valor.I now quietly exit the room.

 

like I said earlier in the thread... my stock motored car with tfs stage1 cam and associated valve springs had a pretty big loop to it. Until I throw my abasco maf on and my tuner tuned the car. Now it's smoother then stock with the 42lb green tops, cam and turbo