Okay so I have a 91 base red bird, and I have this thing where a lot of time when I start it up it won't just fire right up like it should it will putt putt and then start up or be delayed, it happens most either first thing in the morning or after some traffic driving or heavier...and it seems like theres some unnecessary drag or something..

I mean to me it seemed like a fuel problem perhaps, clogged injector, or filter? My filter's new damn near so i dont think it's that, and then when my car starts up the oil pressure is about 60-64? and then if i drive it when the pressures high like that under acceleration it will go up to damn near 77 or so and i'm wondering if this is because i've been using 10-30w instead of the 5-30w and i know the viscosity gets thicker the colder, and it's pretty cold in the night/morning here in seattle, wa. After it warms up the pressure goes down to where it should perfectly be usually stays around 40 and increases under acceleration,

I changed my pressure sending unit about a month ago because it was shot and also was keeping my fuel pump on after the car was turnt off because it's also the fuel pump switch.

So i was just wondering what do you guys think this startup problem is?
And Secondly what's a good oil to use in my bird? Should I go back to 5-30w? Should I go synthetic?

The Motor Has 173k on it and is in good shape minus this intermittant issue?

Also I still have the crappy stock cat on there that sounds a little horendous from the side, do they all sound kinda pingy a little?

Can a noisy air-pump drag down an engine?

Some noob questions im sure lol

But i'd really appreciate your guy's help

 

sounds like a fuel issue, possible weak/bad injectors, fuel pump, ect.

 

for the reply

Yeah it sounded like one to me too with the start up, the fuel pump however is about 1year and a half old, that was before i started going to school, and i had to pay for it, i've been suspecting my injectors for a while now...how do I test them? and if an injector is clogged could it be leaning out the air/fuel ratio a little bit?

Also any suggestions on oil?

I've been using conventional 10-30w GTX High Mil. 1. A fellow student of mine told me that these older high mileage engines don't need blend or sythectic, but the additive pack in the high mileaage has the stuff that swells the old seals a little and refreshes them. Is this stuff true? Or is sythetic the way to go no matter what?

Sythetic seams like the way logically because of the better temperature protection/wear protection,friction component, and added detergents. What do you guys think?

 

been a lube tech for many yrs and mechanic for longer, 10/30 or 5/30 would be fine,isnt much of a difference for that matter,slight but not enough to make oil pressure spike more than another. the brand of oil is personal preference. i like valvoline myself because of how clear it is and can see any particles in it

 

Thank You Formula89 i'll note that for sure, just when it starts up in the morning and that oil pressure gauge goes up to damn near 80 it scares me a bit...i didn't even think pressure went up that high. and like..after the oil heats up a lil and thins out it fires right up, but then after heavy driving it does it too...hmm

Also I was wondering about the cat, because i have a slight miss i think as well, just slight, but i was wondering if it could be a clogged cat, back in school i heat tested it with a temp gun and the back of the cat wasnt heating up like we would have liked it too...because my wires, plugs, distributor, filters, are next to new..just wondering what you guys think...

And i have a really noisy air pump as well is that normal with you guys, it almost seems to drag the engine down a bit??

Oh and is it worth it to change to amsoil or rp?

Also could it be the ignition coil for the starup? I've never changed it as long as i've had the car??

Thanks again in advance

 

Thanks for the suggestions so far, oh and I used the lucas injector cleaner/ upper cylinder lube and it starts right up, and is running crisp, but is this just temporary?

any more input would be greatly appreciated