I had just bought this car last fall and it ran great. i only put 1 tank of gas through it before it winter started and I put it in the garage. Now it starts hard and when it does it only runs 2-5 seconds and then dies again.

I think I will do a tuneup since I just bought it, but am looking for any ideas if anyone has run into something like this. I had never run it in colder weather, so could it have something to do with that?

I think this weekend I will try to change:
plugs
fuel filter
battery
check all vaccum lines


I know 4th gens (LS1 cars) like the back of my hand, but this is my first experience with working on a 3rd gen, so I'm a little lost.

 

Welcome aboard thirdgen.org.

Plugs and fuel filter are a good idea. But, I suspect you've got a problem with your fuel pump relays, and possibly oil pressure switch.

 

Check to see if your ECM stored and trouble codes. If so, post em to pin point the issue at hand.

 

thanks for the suggestions guys. I actually bought the car off the classifieds here last fall.

There are no codes in the ECM, just get 12 three times.

bought some stuff today, but didn't get a chance to change anything yet.

 

Not saying this is the problem (don't know enough to say one way or the other) but when the MAF goes south on these cars you will often get them to start (becuase it doesn't look at the MAF while cranking on the starter) but then they shut down again as soon as the engine fires up.

Diagnostic check for this: unplug the MAF connector. If the MAF is at fault, it'll start and stay running, although it will through a check engine light, obviously.

Just one to keep in the back of your head if other fixes fail to fix the problem.

 

... if you disconnect the MAF, you will set off the SES light, but your gas economy will go down because the ECM will switch over to default mode.

 

tried the MAF disconnect. It ran a little longer, but still died. I did find out the clip that holds the MAF connector on is broken, so that was a good find. It would have been prone to falling apart.

 

Mine still is broken. But as long as it doesnt fall out, then your good to go. There is one for sale on ebay that is color coded. The others are just 1 solid color. Good Luck.

http://cgi.ebay.com/ebaymotors/85-89...Q5fAccessories
http://www.repairconnector.com/produ...or-5-Wire.html



http://www.bmotorsports.com/shop/pro...roducts_id/780

http://cgi.ebay.com/ebaymotors/ws/eB...d=400080166268

http://www.summitracing.com/parts/PCO-5649PT/?rtype=10

 

awesome, thanks for the link!

replace the fuel filter and pcv, no change.

 

 

replaced the TPS and IAC. rented a fuel pressure tester, hooked it up to the passenger side valve, and no pressure! I can hear the pump running and replaced the filter... regulator next?

 

If the pump is running but no pressure then it could be a really plugged filter or it could be that the pump in the tank - intake sock is really pugged with garbage or the hose split in the tank and it's just dumping the fuel right back in the tank. Car should have about 45PSI at the rail. it could also be a weak pump but then you would see some pressure at the rail I would think.

 

well, i changed the filter already.
looks like I have to drop the tank. and its full.

 

I cut an access hole for the fuel pump and pulled it. The rubber hose connecting the hardline to the pump was split in half! cheap, easy fix.

 

hey - great find! Thought it could be that. Make sure you replace that rubber hose with fuel injection hose - not just regular fuel line or you will have this problem again. Reg fuel hose is good only for a few PSI - put throttle and TPI cars have much more pressure so need the better hose that is rated for that pressure.

How big did you have to cut that access hole? On mine the sending unit wrapped over the top of the tank and then into the tank to the pump and I don't think I could get the whole unit out through a hole to get to the pump. Any pics?

 

check out this sweet @55 fuel pump access hole. Very clean and by far, the best Ive seen.

 

Wow - that is sweet looking. Almost makes me wish I didn't spend 2 weeks ripping my rear rusted suspension apart to get the tank out!

 

Yup. Im thinking about doing the job too! It really took you 2 weeks to get your tank done? It only took me around 5 hours to drop and install a fuel pump.

 

Well - I could not get the bolts off the panhard bar or the support brace, then the high pressure line from the tank to the filter was rusted and need much swearing to get it apart without breaking that line - got the rear out of the way but not enough etc so after fighting with it for about 8hrs over the first week - then put it back to find I had the wrong pump (not enough pressure) and had to do it again that took another week....An now after months of working on other stuff - I was doing body work in the filler area and I saw what could be a crack in the filler weld to the tank - ugggh

 

Understood. That sucks bro.

 

the hole I cut was 7.5" wide and about 10" long. It was pretty easy to do, just made quite a few trips to the hardware store. Just got a peice of sheet metal 8" wide and cut it to 11" long. drilled some holes through and used pem nut retainers and bolts. I put some weather stripping around it to make it seal.

turned out pretty nice and was easy! Wish i would have taken a few pics, but its back together now.

 

Good deal bro.