Thread: Starts, runs five seconds and dies

Finally got the engine "running" in my race car after yeras of building the chassis.

The engine starts very easily. Runs for five seconds and stalls.

It sounds beautiful when running, smooth, purrs like a kitten.

If I blip the throttle it will stay running longer, but if I try to keep it at any steady RPM it will die. When revving the engine, the engine will stumble a little.

Engine came from my last competition car, and has had EGR, AIV and BPT deleted. Wiring harness is built up out of sub-harnesses from 2 or maybe even three cars. Point is, it could be anything at this point, but I'm hoping someone recognizes the symptoms and can point me in the right direction.

I'm leaning towards vacuum leak right now, myself, but I could be completely full of it.

check your grounds.

That's one thing I know is good. Identified all the grounds from the FSM and made sure all of them were good and solid even before I tried to fire the engine.

MAF?

Fuel pump or filter? Mine did that, and the fuel pump was on its way out. Vacuum leak, it is possibility, but a maf that has a huge leak post sensor could do that. Or a bad one. My supras had it that issue

I've got a handful of MAFs, so it's easy to swap and try that. Will do.

All new fuel lines, new fuel filter. Pump is older, but is a Walbro 255HP that was working great when moved to this car (along with this engine). I need to get a fuel pressure gauge, I think, to make sure it's flowing as well as I think it is. There is always the possibility that something got kinked under the car when I put the tank in so such. Engine will fire right back up after dying with no issues, just won't stay running.

What RPM does it idle at for those 5 seconds?

Found the problem. I'm an idiot.

The idle air connection under the throttle body has nothing attached to it (the intake I'm using doesn't have a place for it either). I'll swap in a stock intake after work tomorrow and I expect that'll fix it.

Talk about your massive un-metered air leak.

Lol don't worry I did the same thing about 3 weeks ago when I did a swap in my civic LOL

So, after I got the kids to bed I pulled out the crap intake and stuck in a stock unit, plumbed it to the idle air and fired 'er up.

Purrs like a kitten. Thing of beauty.

Thanks for getting me pointed at the MAF and air flow guys, I was all ready to pin it on vacuum or electrical and could have spent a ton of time chasing stuff while ignoring the obvious.