Hi, I just got my engine rebuilt and had someone put it all together. We ran into some trouble with its first start. Had to adjust the timing by ear since he didn't have a timing gun or anything (probably doesnt help he didnt want to bother putting in the new spark plugs i got). Once we finally got it fired up, it had a rough idle that he said we had to just let it work itself out, and we ran it down a couple blocks to get gas in it since the needle was on E and brought it back. When everything seemed fine, except the fact my temperature gauge wasn't showing temp, I popped the hood to see the wire wasn't connected. Plugged that in and notice the engine was roughly about 250 degrees... Hadn't run for long like that, so I don't think it caused us issues but possibly. Also, the thermostat wasn't agreeing with us. The car kept spitting water and antifreeze out of the radiator (with cap removed). So he took it out and cut it apart and put back in, the car doesnt hardly reach operating temperature now (we put a 180 in even though the stock appears to be a 195, not sure if that was what the problem was). After we did that it was set to go, still had a rough idle to it. Drove for the most part fine all the way to work. Then after work it would start then stall out couple seconds after, no matter how many times i tried. I replaced the fuel filter, didn't help. Eventually I wen't and disconnected the MAF sensor, and the car stayed running. Though it had a worse idle and stalls on occasion when stopping. Took it to a shop to get things checked out (checking for blown head gasket, ect.) and we got the MAF replaced and the TPS checked, those are good. The shop told me they don't see it having a blown head gasket, that the fuel pressure is running at about 20 psi, when it should be at 45... They tried to adjust the FPR to raise the pressure, but 20 is the most they can get. They are telling me I need a new fuel pump, and it does sound pretty weak when I turn the keys. But the most troubling thing to me at this moment, and what is the real question after all the info I could possibly think about putting down for now, is when I pull the dipstick, I see it's level is good, but the oil is a light brown (not milky) just looks diluted I guess you could say. When I smell the dipstick it almost seems like I'm smelling gas. Oil pressure stays high btw, on cold start it's usually around 60, only time I've seen it lower is once the engine warmed up after I drove it for the first time, lowered to about 30-40 while idling and increased to 50-60 while driving. Any idea's what could be going on here? Just replace the fuel pump and change the thermostat to a 195 just to be safe and hope it solves all these issues?

1988 Firebird Formula 350 TPI

 

Sounds like a couple things might be wrong..

What I would do - For the oil in the gas, get a multimeter if you don't already have one and test the resistance (ohms) of each injector. See if there's one or two that are significantly different than the other, could be a leaky injector.

For the low fuel pressure - Could be tied in with the injectors, but I'd also pull the vacuum line off of the fuel pressure regulator and see if there is any fuel in it. Or if you're feeling really ambitious, pull the whole fuel pressure regulator off, open it up and see if the diaphragm is torn. I wouldn't worry too much about the fuel pump in the tank, if they're going bad they'll just stop working, they usually don't slowly die.

And finally for the overheating issue.. Since you say you had your engine rebuilt, did they replace the water pump put the correct pump on it? Serpentine belt would use a reverse rotation pump, v-belt would use standard rotation.

 

I do have a multimeter, I'm going to college to earn a degree in automotive technology and it's required to have it of course. I'm not too far in so I'm not exactly sure how to check the ohmns on the injectors, I get the idea though since I have checked my TPS with it. Just would have to ask where exactly do i put the positive and negatives? dont want to screw anything up if I do it. The water pump is new and was ordered as an exact fit for the car, so I'm sure its the right one. I'm actually about to go out and check the FPR actually, I read a couple ways to check those out. I'll let you know.

 

Well now it's back to starting and stalling out a couple seconds later. I almost never hear the fuel pump anymore, and if I do its a really pathetic sound...

 

ok, so i went back out to check the injectors, i was getting about 0.014k ohms on each injector, so i believe they are good. in addition i pulled the vacuum off the FPR to check for leaking fuel, checked good. Then when I put the vacuum on, i thought about how earlier this morning i pushed the vacuum onto it more snug just in case, and thats when the car didnt want to stay running more than 2 seconds. so when i put back on i just put it on enough that it wasnt going to fall off or anything. started the car and it ran smoothly at 900 or so rpms (i do have the throttle set a little forward in hopes of keeping rpms up when i come to stops to avoid stalling, but it doesnt work anyways). But the rpms stayed smooth for a while, i gave it gas and it revved perfectly fine. after letting it idle for a bit i notice it dropped to about 700 and started its rough idle again. so am i looking at a vacuum leak somewhere here?

 

ok, so i had pretty much given up on trying to figure out the problem myself, and i have taken it to two different shops. the first one was already stated above, they replaced the MAF sensor, claimed to have adjusted the timing correctly, and say that its getting 20 psi out of 45 for fuel pressure. They say I need to replace my fuel pump. I took it all the way to another shop out of town that I, and several people I know, trust. They took a look at it and said everything is checking out fine, fuel lines and vacuum lines. They say the fuel pump doesn't need replaced, instead I need to get rid of my aftermarket air box and go back to the stock. So im confused at this point because theres no new modifications to the engine, its all the same stuff it had when I first bought it, just freshly rebuilt. So why would my air box need replaced now? They tell me the car is getting too much air, so I almost wonder if it really just isnt an o2 sensor?

 

the engine now has about 60 miles on it.. through some very short driving and test driving. I would like to say what codes are stored, but I havent had them pulled yet. I tried to bypass it but it seemed to act funny, though I know i did it right cause it gave me code 12 first, just didnt like the sound of something running and eventually it seemed like the light just stayed on, maybe the clip just slipped or something, but im not that concerned right now. For the most part, I dont have a check engine light on when the car is started. I took it to a dealership who just told me to take it to a performance shop, and after getting it back it ran without stalling, but backfired really bad. I ended up pulling the spark plug wires and uncrossing them and redoing the firing order. Now its back to where it starts, but stalls when sitting still and needs to be power braked. The oil seems to be fine now, I hardly smell gas, its getting to a dark color that I'm familiar with. There is still a lot of possibilities im troubleshooting.. but I read something about how it could be a crankshaft/camshaft position sensor. So my question at this point would be, if when the engine was rebuilt, the guy reground the crank, would this make the sensor read faulty now? let me know