Well, my problem still stands. I have half the vaccume(10 Hg) I used to have before the turbo and reflash(20 Hg).

I have redone the HO manifold and adapter plate gaskets 4-5 times. I even took it off and put the stock 2.4 manifold on the see if it was the manifold, nothing.

I have taken off the AC, Accessory lines seperatly and plugged them, not it. I have switched out the FPR line, not it.

Even the compression test came out fine 150, 160, 160, 160.

I even switched out my RC injectors for the stock ones thinking, since the RC's are shorter maybe somehow it was pulsing directly onto the gasket and causing it to leak....nope

I am at a loss as to where else to look, or what it could be. Any ideas??????


Jason



USACi =>146.9db
14.88 @ 90.73MPH =>GM Charger, Motor Mounts, Catback exhaust

A less than perfect idle will cause changes in your idle vacuum. When I switched out all my stock intake piping for the turbo, I also lost some idle vacuum. Tuning your idle pulsewidths should get you the maximum possible vacuum reading (lowest), as well as best throttle response and pickup.

if your rc injectors seem "shorter" then the stock ones you may have the retaining clips installed incorrectly. i had to modify my clips to allow my injectors to fit properly. i doubt this is your problem but i felt it was worth mentioning. i had the newer style injectors stock. unsure of details on them but they were the composite body ones not the metal bosch style ones. i installed siemens deka injectors that were the same style however the clips didint fit so the injectors didint seat properly. they went to deep into the fuel rail. i had to modify the clips so they would roate the corect direction and seat the o rings fully on both sides. the o rings were a tad closer together then the stock ones but its secure in there.



99 Turbo Sunfire GT | Ram 2500 | International Rollback | Mr Hanky the Suburban

Do you have cams or a aftermarket throttle body?

CNFX>vbz wrote:Do you have cams or a aftermarket throttle body?

he shows a 56mm TB listed in his REG




I was a retard, and now I'm permanently banned.

Excidium.......I don't quite understand, so if it were say running rich, and I turn the fuel down w/my SAFC that may correct it?? If you can explain how that works a lil that might help me. I know you've been around and know your stuff.....so lil more in depth pleeaase.

When I say the injectors are a lil shorter, I mean they can not go into the head quite as far as the stockers.

No cams, but I have a 56mm TB from the HO mani. Although I have also ruled that out, since I changed it back to stock, when I switched the mani......guess I forgot to mention that.

Jason




USACi =>146.9db
14.88 @ 90.73MPH =>GM Charger, Motor Mounts, Catback exhaust

your compressions is low , the 2.4 should be above 180

Quote:

so if it were say running rich, and I turn the fuel down w/my SAFC that may correct it??

Yes it may, IF you don't have another problem like a vacuum leak, a manifold leak or a crack in the block somewhere... Also cams/aftermarket tb can cause this behavior.

I find I run approx 15 inHg when I first start my car. I'm on the stock system right now so my MegaSquirt unit isn't able to control the fuel, so the car doesn't reach minimum map, since the stock computer commands a stoichiometric afr at idle and minimum emissions. Well we want best idle response and smoothness, so we tune for the lowest possible map. This means that once you find it, enleaning or enriching the mixture will RAISE the map. If you play around with the idle enough, you should be able to observe the MAP raising or lowering depending on your adjustments. I wouldn't worry about what your AFR is (within logical limits), just tune for the lowest possible map and see what you come up with.

Excidium.....I think you have me on the right track, I just switched the reflashed ECU for a stock one, and the vaccum increased(from 10 to about 18), I'm guessing that is because the reflash would be giving it more fuel at idle(longer pulses), does that sound correct?

Jason




USACi =>146.9db
14.88 @ 90.73MPH =>GM Charger, Motor Mounts, Catback exhaust

Key point: Idle air to fuel ratios most certainly affect idle manifold pressure/vacuum.

I thought you had an SAFC this whole time... You may not be able to adjust your mixtures, and thats a problem with boost. You might want to invest in a better fuel management system if you want to tweak your air to fuel ratios with any measure of accuracy. While a wideband isn't important for this, since u can tune by manifold absolute pressure, it would definitely help with the rest of your fuel map. I guess you could do fine tuning with your base fuel pressure, but imo this is never the way to go, as it affects your entire fuel map, and since u can't tune your fuel map very well, thats not a good idea.

You may have to live with that rough idle while using your reflashed ecu..

To recap: Going too lean or too rich past a certain point at idle can cause a rise in your manifold pressure. You need to tweak it with your fuel management (if you can) to achieve the lowest manifold pressure possible, or in other words, the highest possible vacuum(highest inHg).