Alright guys I'm in need of some help here. I've replaced the cam with the comp computer controlled and valve springs to match. I also replaced the iac,tps, plugs and wires and made sure my timing was dead on, also put new Bosch III injectors in. the problem is I have a miss that wont go away its worse when cold but still there when at running temp. I thought my CSI was leaking so I pulled the whole rail off and put another set of injectors with clip to hold them on the fuel rail cause the boshs dnt have the clips. The problem is I have no fuel pressure it comes up to 40 psi then drops after pump kicks off, so I clap the return line and the pressure stays at 60 psi as long as it clamped. Also the CSI is not leaking even with that kind of pressure on it so do u think the pressure reg is bad. I also replaced it with a used 1 earlier but it was 1 that I had extra I did not replace the whole assembly I jus took the top off and changed the diaphrams. It looked good was not dry rotted and didnt have any holes so why wld I loose my fuel pressure?

 

just curious which cam you put in. Not holding fuel pressure maybe the spring is weak or broken?

 

I got the comp cam 08-300-08 and valve springs to match. I thought the miss was a vacuum leak but ive searched every thing over with carb cleaner and cant find a leak any where I'm just at a loss now. I even changed the fuel pump and cleaned all the lines thinking it wasnt getting enough fuel but when I took the intake runners off it looked like alot of fuel n the intake runners. I wont mess with it much more and I will put a carb on it.

 

What year is the tpi

 

Its a 87 runs out good but has that stupid miss to it and when its at running temp some times if u just barely crack the throttle off idle it will die. Its starting to pea me off just want it to run like it should with all the new stuffi have thrown at it.

 

Did u tune it?

 

No need to tune it, its a computer controled cam and stock 19# injectors. I have adjusted the minimum idle and little stuff like base timing. Its got me confussed im jus gonna have to step back from it for a while and think on it. May try another fuel rail I have laying around just to see if the regulator is good.

 

Well I tried another fuel rail I had and it done the samething as mine did. It wont hold pressure so I took the regulator top of it and it also looked good. I was jus wondering if the fuel pump pressure test cld be done with the fuel rail off or wld I get bad readings?

 

Anyone have any input?

 

If pressure holds with return line clamped then your regulator is faulty and leaking pressure

In any case
if the pressure comes up and holds at correct pressure while engine is running , leaking reg is not source of your miss.
Just a cause of longer starting

 

I will do a check with it running this evening after work, but as of last night pressure was 40 psi then bleeds down to bout 25 psi and all this is done with fuel rail unbolted and fuel rail raised, with no injectors leaking.

 

about the miss do you have a rust on the dizzy reluctor wheel? i had a small crack in mine and it gave me this stupid miss for 2 years. just a thought

 

The distributor looks good. I did find a couple plug wires leaking tonight but only sparked when I revved it up. I'm gonna change those again 2mar and cut the cat off. It idles good but has a slight jerk to it also if I just barely give it gas it will die llike it smothers out. Almost positive its not a vac leak but its gonna drive me nuts if I dnt figure it out soon.

 

If you put in a larger cam, it is likely that you are running a lean mixture when the car is cold. The computer may be able to compensate for it when it goes to closed loop, but it sounds like it has issues there as well.

There is no such thing as computer "controlled" cam. There are computer compatible cams, which mean little tuning is required to get the benefit.

Get a datalogger and see what the computer is doing in closed loop (warmed up) and you'll know if you're running lean.

Don't waste your time guessing.

 

Yea the data logging wld be nice but I dnt have a laptop and the stuff to do it so for now its out. I did a compression check today it turned out good the highest reading was 140 and the lowest was 120 all the plugs look good so fuel and spark are there. The reason for the compression check was it has some blow by guess I may have some broke oil rings or something. I just cant seem to get the miss out of it, I did notice the miss gets worse if I take the oil fill cap off. Really not sure if its worth all the hassle of a complete rebuild but it sure does suck spending all that money and coming out worse than what it was.