91 L98 Starting problems (any help)
Thread Starter
2nd Gear
Joined: Mar 2010
Posts: 2
Likes: 0
91 L98 Starting problems (any help)
So I just bought a 91. It's my daily driver but I'm having starting problems. When I go to start it when it's cold it cranks and turns. I have to turn the key forward and crank it untill it finally starts up. And other times the same thing happens except when it starts up it's shuts back down on me. So I have to keep it on giving it gas untill I go down the block and it's fine from there. The car doesn't shut off on me any other time. I've changed the plugs, cap,rotor, and fuel filter. And now I'm thinking it's a fuel problem. Maybe not enough pressure from the fuel pump or clogged lines or something. Any help would be appreciated. If it's happend to you or anything. Thanks alot.
Drifting
Joined: Aug 2006
Posts: 1,279
Likes: 0
From: Delray beach FL
check your volts first.
could be a fuel pressure problem. Buy a fuel pres gauge cheap , it direct connect to the passenger side for the 91. check for some good plug wires too.
could be the ECM going slow on check up too. Can happen too. Once ok, it s crack it up right. To check if it is so, put on ignition without starting one, cut off, and put it on again, wait 4 secs, start engine. If it starts, it an be a slow thinking ECM problem related to a sensor going slow.
could be a fuel pressure problem. Buy a fuel pres gauge cheap , it direct connect to the passenger side for the 91. check for some good plug wires too.
could be the ECM going slow on check up too. Can happen too. Once ok, it s crack it up right. To check if it is so, put on ignition without starting one, cut off, and put it on again, wait 4 secs, start engine. If it starts, it an be a slow thinking ECM problem related to a sensor going slow.
Team Owner
Joined: Mar 2001
Posts: 54,124
Likes: 30
From: Cincinnati, Oh USA
Buy a fuel pressure gauge (about $12) and connect it to the Shrader valve at the end of the right fuel rail. You should see 35-42 psi and it should be fairly constant with the engine running. Also see if it holds up for a long time with the ign off. Rapid pressure drop indicates leaky injectors or a leaky check valve in the fuel pressure regulator. Leaky injectors will cause a too rich fuel/air and you will likely see black exhaust smoke. Pull a plug wire and bring a grounded wire close to the plug boot while someone cranks. You should see easily a 1/2 inch snappy spark. Weak spark can cause hard starts and poor running. Use a timing light to confirm proper spark timing. Unplug the MAF and start the car and drive it. If you experience easier starts, you may have a defective MAF. Pull some cold plugs and look at their condition, they should be white and dry. Wet plugs indicate leaky injector or leaking head gasket.
Burning Brakes
Joined: May 2007
Posts: 965
Likes: 13
From: turn 12 at Road America or TX
It sounds like you might have a defective fuel pump relay. Go here
http://forums.corvetteforum.com/c4-t...jectors-2.html
and read my description of the interaction between oil pressure and the fuel pump dated
11/15/09. If the fuel pump relay is bad, you have to crank the engine until it makes about 4 psi oil pressure. Is that the issue with your 91? Your description is a little vague.
http://forums.corvetteforum.com/c4-t...jectors-2.html
and read my description of the interaction between oil pressure and the fuel pump dated
11/15/09. If the fuel pump relay is bad, you have to crank the engine until it makes about 4 psi oil pressure. Is that the issue with your 91? Your description is a little vague.
