OK I love this place. this is my first post I hope somone can help. I bought my 85 Trans AM with 5.0 TPI engine (code F) and it bad thottle responce and sounded like it was missing up to around 2000rpm . I also had the 700r4 trans rebuilt with second gear opend up and a corvette servo and torque converter. aomone had the fan hot wired and the guy I bought it from told me that is how it was when he put a new radiator in it I found the relay in the center console and it works.I was getting a coad 42 so I replaced the EGR and Heat sensore,also new 8mm plug wires and autolite plugs gaped and 1 range hotter than stock to help burn some of the oil leaking past the valve seals.
New cap rotor coil I set the timing to 6* BTDC with the EST unpluged and and same problem nothing changed. After further inspection I found the orange wire to clear the codes out was broken and I fixed it and it cleared my Code 42 now I have no codes but still same problem it starts great idels not bad but when I put it in gear in runs ruff and sounds like it is missing when i take off up till 2000 + RPM then it feels better. tryed to reset the timing again maybe I will mess with that some more I bought a vacume gauge so I will check that out I also have replaced all the lines I could see that looked bad. the cruise does not work I wonder if it is related at all and the A/C is unpluged and no belt but turn by hand the air pump also has no belt on it so it is not working eather. OK that is as much info I can think of to help hope it is enophe.

 

Try unplugging the vacuum line that goes from the EGR solenoid to the EGR valve on the intake manifold (underneath the plenum) and plugging the end with a screw or something (don't wreck the line, and be very careful with the hard plastic vac lines, they're quite brittle).

I had the same problem, my EGR solenoid was stuck on all the time.

 

I set the timing with a vacume gauge to get the most vacume and it runs alot better still a miss and the timing mark does not even show up an the tab. but it runs noticably better but it is way way advanced if I go by the timing an the crank. What is up with that? The Timing mark is facing tawards the passenger side of the car.

 

Kicker,

Welcome Aboard!

First, set your base timing back to 6° BTC as you did before. You don't need any more variables than necessary when trying to diagnose a problem. The reason that the marks don't appear on the balancer is that the EST is advancing the timing as much as possible for best performance. Make certain you bypass the EST before setting the base timing.

If all your ignition components are new and reliable, you should probably perform a power balance test on the injectors. Do an archive search and you should find a post where I outlined the procedure. Don't be surprised if all your problems are from poorly matched injector flows or poor spray patterns. Of course, a fuel pressure test is a good start, but that is in the procedure as well.

If you don't find the procedure in the archives, let me know.

 

I dont know if My est is working right I set the timing with the est diconected and when and the mark was still way off then conected it an dit ran the same eather way I drove it for about
1 1/2 hours yesterday and it ran the same waythe whole time if the timming was that far off it would have a hard time starting right? It ran a whole lot better but still a little miss like a bad plug wire, confusing about the timming you would thinkif it is that far off it would run worse. I dont know this car or know what has been done to it or who worked on it before that always makes it fun. I am going to change the fuel filter today and retry messing with the timing. then I think it is time for somone who knows what there looking at to have a try. I will be sure to post the outcome as I am sure it will help somone else.
Thanks to every one who replyed back and if you have any other sugestions great. have a nice weekend