Engine Cranks, turns on, kinda sputters, then shuts off

[Antbankstwo3]

So I am currently working on a 87 GN. I have been cleaning up some things and replacing a few parts. I just recently purchased it and it did run. I wouldn't say it ran well but it ran. I really don't now the cars history & my goal is just to get the car running correctly and efficiently. Its pretty much stock. When I try to start it, it will crank, start up for a second or few, sputter and shut off. If I give it a little gas, it will sometimes stay on for a few seconds more, then eventually shut off. That's where Im stuck.

So here are a list of some things I have done just so you know:

New upper plenum & throttle body
New spark plugs
Replaced spark plug wires with a good set of Magnacore's
New O2 sensor
Replaced IAC valve with a good used one

I've done more but I don't think its things that would interfere with engine starting. I do have a scanmaster I just got off a member here, but don't have it hooked up yet. Its taking me some time to get where Im at now and most of this is new to me with the GN. So I am just wondering what would be my steps into resolving this issue. Also, the fuel pump is priming so that is working correctly. Thanks in advance!

Side Note: I did have lots of things unplugged but I plugged it all back in. Traced my steps. I don't know if unplugging the TPS & IAC would have anything to do with it.

 

[TRICKSIXPA]

Have a scan master? When it dies does the check engine light come on?

 

[Venomns]

Crank sensor maybe?

 

[Venomns]

Or cam sensor I mean?

 

[Antbankstwo3]

I just actually got the Scanmaster but haven't hooked it up yet. When it dies the check engine light does come on, but doesn't it come on when the key is turned to the on position anyway? I will double check tho.

 

[bison]

Check fuel pressure


Sent from my iPhone using Tapatalk

 

[hiboom]

Go to Vortexbuick.com go through the trouble shooting guide (tree) will save you a lot of time and headake

 

[buddy]

Forgot to plug in ECT sensor?

 

[Antbankstwo3]

Go to Vortexbuick.com go through the trouble shooting guide (tree) will save you a lot of time and headake

Thank u! I will do that

 

[Antbankstwo3]

Forgot to plug in ECT sensor?

What does ECT stand for? I think plugged everything back in but I will double check.

 

[buddy]

Engine coolant temp sensors. There's three of them. One tells the ECM the temp of the engine.

 

[gsgnnut]

map sensor?

 

[Antbankstwo3]

Engine coolant temp sensors. There's three of them. One tells the ECM the temp of the engine.

Actually, I did jus realize I left the water temp sensor unplugged now that I think about it. Could that cause any problems?

 

[gsgnnut]

sorry, meant MAF not MAP

 

[gsgnnut]

it definitely would cause the ses light to come on and it might not run very well.

 

[Antbankstwo3]

it definitely would cause the ses light to come on and it might not run very well.

Ok I will troubleshoot that area.

 

[Antbankstwo3]

I havnt had a chance to go look cuz of wirk of my work Schedule. As soon as I do I will update.

 

[Nascar83Fan]

Welcome to the turbo buick family first off. I hope you get your GN running good again, you'll find quite a few helpful members and vendors here in this community. Where abouts are you located? Maybe there's some members near you that could lend you some help with getting your GN running right again.

I am sure you took the liberty to replace the fuel filter with a new one depending on when the previous owner had did so. Might need to put some fresh gas in, if your car sat alot but was started up frequently could be old gas making it run bad. But getting the scanmaster hooked up would help quicken the process of figuring out if there's codes and what codes are being thrown along with other bits of info the scanmaster can show. These cars typically need at least 38+ fuel psi to start and run properly, so verifying that would help eliminate a fuel pressure issue. You did mention you changed a couple things, if it still has the factory chip in it depending on the changes that were made might make it run a bit rough. Keep us updated please, so we can help point you in the proper direction.


Posted from the TurboBuick.Com mobile app

 

[Antbankstwo3]

Welcome to the turbo buick family first off. I hope you get your GN running good again, you'll find quite a few helpful members and vendors here in this community. Where abouts are you located? Maybe there's some members near you that could lend you some help with getting your GN running right again.

I am sure you took the liberty to replace the fuel filter with a new one depending on when the previous owner had did so. Might need to put some fresh gas in, if your car sat alot but was started up frequently could be old gas making it run bad. But getting the scanmaster hooked up would help quicken the process of figuring out if there's codes and what codes are being thrown along with other bits of info the scanmaster can show. These cars typically need at least 38+ fuel psi to start and run properly, so verifying that would help eliminate a fuel pressure issue. You did mention you changed a couple things, if it still has the factory chip in it depending on the changes that were made might make it run a bit rough. Keep us updated however please, so we can help point you in the proper direction.


Posted from the TurboBuick.Com mobile app

Thanks and I really appreciate the advice. I have not got to the fuel filter yet, but that is coming up soon. Im in the process of hooking up the Scanmaster to diagnose it. Hopefully will get to that tonight. Also, I do live in the area of Nick Micale of Arizona GN. I have spoke to him on occasion. After I can get it running at least descent, I am taking it to him for some work.

 

[Antbankstwo3]

YES! So I got the car running. I guess I over looked the MAF. It was not hooked up. DUH...SMH. But I'm glad its running. Its still not running correctly tho. Im sure its because I replaced the IACV and swapped the TPS to my new throttle body. So I will have to get that adjusted. Any advice on that will help me. Also, the check engine light is on. It was on when I purchased the car. I was hoping by changing the O2 sensor it would help, but its still on. Any Ideas there would be appreciated.

Thanks!