Hey guys,
It's me again. Sort of an update I guess,, I haven't had to whine for a coulpe of weeks 250 miles later I'm still having oil blowing back through the breather tube but I'm taking the car to the guy who built it tomorrow.

But that problem is out of my hands,, the questiong I have is only at cruising speeds the engine seems to be misfiring or hesitating (jerks in any gear) and at idle it seems to be hunting for the correct speed. The IAC motor appears to be operational and is very clean (and oiled thanks to vaders tip-o-the-day). It's an 87 305 tpi motor 5-speed. nothing is very wild to it. I'm 97.63% sure most everything is set right and the ECM is (new) fine.

It takes longer than normal to start but cold idles steady at around 1300rpm then after roughly a minute it drops to normal idle (700ish rpm)and starts it's crap with normal idle,, sputters/stumbles (almost like turning key of for a split second) and drops low (450-550 rpm) then back to higher idle & repeats. Driving rolling to a stop,, it drops and then sputters weakly around 500rpm and then it just dies.

Could this be a vacuum leak ? or something else causing this ? the jerking in gear is relly annoying and the tranny doesn't seem to enjoy it either. any thoughts, ideas, questions, or comments are appreciated.

I'm going to turn it into a realFirebird soon if it doesn't quit giving me it's b.s.

Thanks guys

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Da Boid

- 4 out of 5 people think the 5th is an idiot

 

DB,

It could be a lot of things. Vacuum leak, poor injector(s), sticky/leaky EGR, fuel pressure, TPS adjustment, too many to cover thoroughly.

If you could inspect the vacuum hoses, that would eliminate that possibility. A manifold vacuum reading would be good. A resistance test of the CTS and MAT sensors might be useful. A fuel pressur test would be really good. With that information, the diagnosis should be much easier.

You could also temporarily disconnect and plug the vacuum line to the EGR to eliminate the possibility of a leaking solenoid valve.

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Later,
Vader
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"No matter how hard you try you can't stop us now"
Adobe Acrobat Reader 4.0

 

Hey vader,
thanks for the reply,,, I didn't think to plug off the EGR vacuum line,, I'll have the car until thurs now so I might get a wild hair to go out in this cold mess & try that shortly.

To help eliminate some of the things. I do have a fp gauge hooked up,, it runs roughtly 42/47psi,, the pump (ac delco), filter(fram) & fp regulator(holley) are all new

I have the cruise & EVAP vacuum ports capped off.

The injectors were cleaned and flow matched by TPIS.

I have set the TPS to .54v and minimum idle is at 400rpm roughly. TPS is not new (maybe this is a problem ?)

CTS & MAT are both new delco sensors. The EGR & sensor are both new as well.

It has yet to throw a code so I'm guessing it mat not be too major.

I set the base timing to 8* and fiddled with it from there to get it somewhat more driveable. I have all MSD ignition (maybe the 6AL box causing a problem?).

I believe I've covered most of what I can think of at the moment to help.

It has the factory cam with crane 1.6 rr's but I wouldn't think that would cause a fuss with a MAF engine would it ? I have a BBK 52mm tb too,,, and I do question it's quality,, or is it just sounding more like a vacuum leak ? I'll try to get ahold of a vacuum gauge soon.

Thanks again for any & all help