Only 5lb boost, erratic idle

[dadsbad]

I took my car out yesterday and got on it; only 5lb boost and performance not what would be considered normal for these cars. It also idles erraticly and I did hear a little pop a couple of times when giving gas at low speed.
help please.
Thanks, Jim TTA#917
I'll get some scanmaster readings tomorrow to post

 

[Quiky One]

Could be a bunch of little things. Post up your scanmaster numbers.

Jason

 

[chrisgarrett]

Do you have a cat?

 

[dadsbad]

Idles rough, only 5 lb boost

First of all I do have a cat on it, probably the original since the car only has 46k miles on it.
Now for scanmaster numbers
AF 16-07 Iac 30-17
L8 69-42 Cc 232.59.241.2.8.16
Bat 14.0 at start up then less Pl 4.3-4.1
Sp 23.4-20.7 idleing
Int 128 02- 628,600,126
Bl 124-129
MPH 00 Help appreciated greatly!
Clt 85-123
Ats 83-85
R 1025, 750, 800
Tps .50 at idle 4.40 at Wot

 

[Quiky One]

You need to get numbers when the car is fully warmed up. The popping could be the coil pack. Have you changed it out with a known good one?

Jason

 

[dadsbad]

more scanmaster #'s

Iac 30-17
cc 232,59,241,2,8,16
Pl 4.3,4.1
Sp 23.4-20.7 at idle
02mv 628,600,125
all these numbers are at idle

 

[dadsbad]

Ok, I'll let it idle till warmed up and redo #'s
thanks in advance

 

[chrisgarrett]

Cat could be clogged. It's 20 years old.

 

[dadsbad]

New numbers at temp

Af 6,5......L8 42,44,42...Bat 13.4.... int 128...Bl 129...Mph 00... Clt 164...Ats 94... r 750-800...Tps .50... Iac 10,9,7,5...cc 18,20,34,38,43,57,up to 124...Pl 3.8... sp 23.8-24.2...02 jumps as normal...no Mal even shows up on the scanmaster now for some reason.
Any help greatly appreciated!
thanks, Jim TTA#917

 

[dadsbad]

Cat clogged always a possibility; and I don't know about the EGR valve. I've thought about blocking it. The car is bone stock except for 50lb inj. and a TTchip that I bought from someone on this board.
Thanks, Jim

 

[dadsbad]

I do have some other parts that are at my son's house; extra stuff from when I had my GN

 

[chrisgarrett]

Your IAC numbers look low. Adjust the Iac to mid 20's range. There shouldn't be any MAL numbers. Thats where trouble codes appear. You're saying that when you try to adjust the boost, it won't go over 5 pounds? That ould indicate too much back pressure from a clogged cat.

 

[Quiky One]

Your EGR is disabled with the TT chip so dont worry about that. Your numbers look normal except the TPS is a little high on the idle side. .44 is perfect. Do you have an extra coil pack you can swap on?

Jason

 

[Quiky One]

Your IAC numbers look low. Adjust the Iac to mid 20's range. There shouldn't be any MAL numbers. Thats where trouble codes appear. You're saying that when you try to adjust the boost, it won't go over 5 pounds? That ould indicate too much back pressure from a clogged cat.

I disagree on the IAC. If it idles fine leave it alone!!!! That wouldnnt cause popping or low boost anyway.

Jason

 

[chrisgarrett]

Another possiblity: If you have 50 pound injectors but a stock fuel pump, you may not be getting enough fuel. And the fuel pump should be hot-wired to the alt. to get enough juice. Whats' the fuel pressure?

 

[chrisgarrett]

I disagree on the IAC. If it idles fine leave it alone!!!! That wouldnnt cause popping or low boost anyway.

Jason

His original post indicated that it idles erratically.

 

[Quiky One]

His original post indicated that it idles irratically.

My bad you're right..For some reason I thought it said low speed...In that case adjust your IAC and TPS and report back.

Jason

 

[chrisgarrett]

Dadsbad,
Is your cat clamped on or welded? You definitely need to adjust your IAC and you TPS, but the boost problem could be related to either you cat or your fuel pressure. Can you remove your cat for inspection, and what is fuel pressure?

 

[dadsbad]

I'll have to check to see if the cat is welded or not and I'll adjust the tps and iac and check the fuel pressure. I do have an accufab adj. fp reg.(not installed yet) what should the fp be for 50lb injectors, maybe around 40lbs/

 

[Quiky One]

Erics chip calls for 44 or 43.

Jason