tuning help

[ryanv]

I'm a newby in the buick world and could use a little help. First my car, I have 86 t-type 48,000 original miles. I installed a scanmaster and have been trying to follow the guidelines as to where the tps, and fuel pressure should be. TPS is saying at .40 and WOT 3.8. I think the TPS should be .42 and at WOT 4.6-4.8. Correct? When I hold the throttle at WOT it only shows 3.8, how do I adjust that?

Also, fuel pressure, I have an 340 walbro fuel pump in it w/o the hotwire kit. Is a hot wire kit really necessary? Fuel pressure is at 42lbs. If I disconnect the vacuum line will that simulate WOT? At WOT what should be fuel pressure be?

I am reading Knock at WOT and thought it might be a fuel issue but I'm not sure. Boost is set at 18lbs which I think might be to high, at the risk of sounding like a dumna-- how should I adjust it? I have seen posts about a good references, is there a book or service manual most people would agree I should be using. Thanks

 

[1 in 2000]

TPS Adjust - Adjusting the TPS

The hotwire to the fuel pump allows you to run a constant full voltage to your fuel pump.

Lower your boost or timing to get rid of the knock.

Lots of how to's and great people on this site. Keep reading and ask questions.

 

[Blazer406]

I'm a newby in the buick world and could use a little help. First my car, I have 86 t-type 48,000 original miles. I installed a scanmaster and have been trying to follow the guidelines as to where the tps, and fuel pressure should be. TPS is saying at .40 and WOT 3.8. I think the TPS should be .42 and at WOT 4.6-4.8. Correct? When I hold the throttle at WOT it only shows 3.8, how do I adjust that?

Also, fuel pressure, I have an 340 walbro fuel pump in it w/o the hotwire kit. Is a hot wire kit really necessary? Fuel pressure is at 42lbs. If I disconnect the vacuum line will that simulate WOT? At WOT what should be fuel pressure be?

I am reading Knock at WOT and thought it might be a fuel issue but I'm not sure. Boost is set at 18lbs which I think might be to high, at the risk of sounding like a dumna-- how should I adjust it? I have seen posts about a good references, is there a book or service manual most people would agree I should be using. Thanks

Most TPS switches pivot up and down (when the screws are loosened).... but can also be pushed toward the firewall and pulled out toward the radiator. You might have to play with it... but you should be able to find an idle setting .46 or less.... and a WOT to be over 4 volts ...say 4.4 or better fairly easy. Make sure you don't have a floormat wadded up or carpet backing under the gas pedal preventing full depression of the pedal too.

Vacuum line off is where you set the FP at 43 psi. It does not simulate WOT. WOT the FP should be the base pressure (usually 43 psi) + boost pressure..... so at 20 psi boost, you should have 63 psi fuel pressure.

Does your wastegate actuator have threads on the arm where it hooks into the puck on the downpipe? Lengthening the arm lowers boost.... shortening it raises boost. It should not be adjusted longer than it would be to just pull it ever so slightly to get it back on the wastegate puck pin.

 

[ryanv]

Thanks, what about timing? Is that something I need to adjust as well?

 

[Blazer406]

What kind of chip do you have? Some are adjustable......some are not....

 

[ryanv]

Good question, I'm not exactly sure, I know it is a 42lb injector 93 octane otherwise I don't know.

 

[ryanv]

I adjusted the fp, and tried adjusting the tps sensor. I can almost get to 4.5 but I than the idle setting is high, somewhere around 1. Is there a trick to getting the idle setting at .42 and WOT 4.6? It seems like it isn't possible? Thanks again.

 

[1 in 2000]

It's a balancing act between the TPS (is your floor matt out of the car) and IAC. You'll have to play with both settings until you get both where you want them. There's no tricks that I know of, other than time and patience.

 

[ryanv]

Thanks again

 

[mikestertwo]

I adjusted the fp, and tried adjusting the tps sensor. I can almost get to 4.5 but I than the idle setting is high, somewhere around 1. Is there a trick to getting the idle setting at .42 and WOT 4.6? It seems like it isn't possible? Thanks again.

You don't need 4.6V@WOT As long as you are over 4.0V@WOT you are ok.

 

[Lou86]

I have the same set up with a TT chip and hot wire additional I'm also getting a knock at 18. My fuel pressure is at 38, going to turn it up to 43 tomorrow and see what happens...

 

[ZNix]

If you are getting knock.. You have TOO MUCH boost. Turn it down to 15-16 PSI. That is a good number for 93 Octane. You need a little more practice with tuning before you start upping the boost.

 

[ryanv]

Do you have knock at 18psi and race gas? I was getting knock at 18psi with 93 oct but once I went with the race gas it was completely gone, the car drive much harder now than with my old chip.

 

[mtbraun]

I adjusted the fp, and tried adjusting the tps sensor. I can almost get to 4.5 but I than the idle setting is high, somewhere around 1. Is there a trick to getting the idle setting at .42 and WOT 4.6? It seems like it isn't possible? Thanks again.

Make sure the square washers are not binding preventing the TPS from being slid all the way forward in the slots. Follow previous posting on adjusting TPS. I had exactly the same issue you did. Take the floor mat out and make sure the TPS is all the way forward. You'll get there.