Spark plug gap
Thread Starter
Burning Brakes
Joined: Oct 2004
Posts: 898
Likes: 1
From: Pearland Texas
Spark plug gap
Spent most of my day working of my car. Still haven't solved the miss, possible cracked intake manifold, but did replace the plugs with AC Delco rapid fire #5's. Gapped them at .035, reading the speck from my Gm manual, Is this right? the AC Delco website shows .045. The darn thing ran fine around the block and once parked it would not restart. 
Would this occur that quickly ? Car is dead in the driveway. Some thanks I get for working all day on her. Any suggestion ?
Would this occur that quickly ? Car is dead in the driveway. Some thanks I get for working all day on her. Any suggestion ?
Thread Starter
Burning Brakes
Joined: Oct 2004
Posts: 898
Likes: 1
From: Pearland Texas
After it sits(15 minutes or so) it fires on the first crank and then it will die. Wont idle at all. After reattempting to start, nothing. it has to sit for a while before it even attempts to fire. I hear the fuel pump clatter for a second and then I try a restart. Wont idle just dies immediately. I did replace plugs on one side last night and passenger side today with daylite making it easier to see. Everything seemed to go back in place easily, but will check it all over tommorrow. If regapping will solve this I will do it in a heartbeat. My injectors all ohm out bad, but I did replace all the connections correctly. Why would they act up now, spiteful I guess.
Le Mans Master
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
Sounds like you have leaky/faulty injectors. You even mentioned they ohmed bad. There are some test that may be benificial. Get a fuel pressure guage on the schrader valve and check what the fuel pressure is when you turn the key "on". The pressure should drop ~2 psi after the pump stops (2 sec). Watch the guage and see how fast the pressure drops. It should not drop say more than 10-15 psi in 30 minutes. The pressure drop could mean a few things, but you will want to pull the plugs to check for raw fuel.
Recheck and make sure you have the correct plug wires on the correct plugs. I believe you are o.k. as long as they are at .035. Check for spark also.
Hold the accelerator to the floor when trying to start next time.
(Just an easy test) Disconnect the MAF and try to start.
Recheck and make sure you have the correct plug wires on the correct plugs. I believe you are o.k. as long as they are at .035. Check for spark also.
Hold the accelerator to the floor when trying to start next time.
(Just an easy test) Disconnect the MAF and try to start.
Le Mans Master
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
Mass Air Flow sensor. It is located in the air duct between the air filter housing and the throttle body. The MAF sends the ECM flow measurments according to engine speed. With it disconnected, the ECM will use default settings instead.
My post should have come after yours.
My post should have come after yours.
Originally Posted by Dads90
I dont see MAF in my manual, I see MAP,MAT could you explain? Thanks
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Team Owner
Joined: Oct 2004
Posts: 81,241
Likes: 3,063
From: altered state
St. Jude Donor '05
Originally Posted by 65Z01
Put a gauge on the Schraeder valve and see if you have full fuel pressure with the key on and that it does not die before the engine stalls.
Le Mans Master
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
Originally Posted by Dads90
Could I have blown the injector fuses when checking the Ohms? Read this in the service manual to check these if it doesn't start, will check into that as well.
Le Mans Master
Joined: Oct 2003
Posts: 6,130
Likes: 2
From: seattle WA
What were the ohm readings on the injector? triple check your plug wires. Hard enough to do with good lighting. Just read your injector post...posted what I believe to be your starting problem there.
Last edited by rick lambert; Nov 28, 2006 at 11:49 AM.
Melting Slicks
Joined: Feb 2006
Posts: 2,753
Likes: 15
From: backwoods upstate ny
re; plug gaps
wider plug gaps WILL reduce emissions at IDLE and tighter gaps will increase high end power....(guess what the manual MUST follow)
''back in the day'' we ran a rail drag car that would go 5 mph faster on top end with plugs gapped at .020'' but et about .05 better with .035'' gap (sbc, injected, vertex mag)
briefly owned a japanese/gm car (my son's high school beater) than would intermittently no-start with plugs at recommended gap (.060'' IIRC) but ran nicely at .035.
''back in the day'' we ran a rail drag car that would go 5 mph faster on top end with plugs gapped at .020'' but et about .05 better with .035'' gap (sbc, injected, vertex mag)
briefly owned a japanese/gm car (my son's high school beater) than would intermittently no-start with plugs at recommended gap (.060'' IIRC) but ran nicely at .035.
Thread Starter
Burning Brakes
Joined: Oct 2004
Posts: 898
Likes: 1
From: Pearland Texas
It Started !
Went to bed brainstorming and disgusted.
The next morning it fired right up. It's idling kind of rough but it's running. The drove it around awhile trying to build up my confidence. Parked it turned it off and restarted fine. Im still going to replace the injectors, possibly wires, put a vacuum check ( when the gauge comes in) on it. Something is not right and I won't rest until its running perfect. Question--Is there a GM gasket kit for all the plenum, TB, runners etc. or do you purchase them seperately, and should I go stock gaskets or a better performance type ?
The next morning it fired right up. It's idling kind of rough but it's running. The drove it around awhile trying to build up my confidence. Parked it turned it off and restarted fine. Im still going to replace the injectors, possibly wires, put a vacuum check ( when the gauge comes in) on it. Something is not right and I won't rest until its running perfect. Question--Is there a GM gasket kit for all the plenum, TB, runners etc. or do you purchase them seperately, and should I go stock gaskets or a better performance type ?
Le Mans Master
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
Originally Posted by Dads90
Went to bed brainstorming and disgusted. The next morning it fired right up. It's idling kind of rough but it's running. The drove it around awhile trying to build up my confidence. Parked it turned it off and restarted fine. Im still going to replace the injectors, possibly wires, put a vacuum check ( when the gauge comes in) on it. Something is not right and I won't rest until its running perfect. Question--Is there a GM gasket kit for all the plenum, TB, runners etc. or do you purchase them seperately, and should I go stock gaskets or a better performance type ?
The next morning it fired right up. It's idling kind of rough but it's running. The drove it around awhile trying to build up my confidence. Parked it turned it off and restarted fine. Im still going to replace the injectors, possibly wires, put a vacuum check ( when the gauge comes in) on it. Something is not right and I won't rest until its running perfect. Question--Is there a GM gasket kit for all the plenum, TB, runners etc. or do you purchase them seperately, and should I go stock gaskets or a better performance type ?
Comes in a complete kit, no need to buy separate gaskets. Stick with it, get some injectors inthere it will be worth it when it fires up and idles like a baby.
Le Mans Master
Joined: Sep 2006
Posts: 6,050
Likes: 147
From: Phoenix AZ
2021 C4 of the Year - Modified Finalist
no-start
I had a distributor with bad module. gets hot, no start. but here in Arizona it is like 118 degrees ambient in he summer time.
normal to see 254 on the temp indicator after shutting it off, cools right down to 211 on start-up, and then slowly dips to 195 city, 189 hwy.
with heating and cooling cycles like that, it's no wonder it went.
try taking the module loose in the distributor, and adding some white silicone conductive grease under the module, and screw it back down.
see what happens...then check to see if you have any previously stored engine codes that might give you a clue to a impending failure
normal to see 254 on the temp indicator after shutting it off, cools right down to 211 on start-up, and then slowly dips to 195 city, 189 hwy.
with heating and cooling cycles like that, it's no wonder it went.
try taking the module loose in the distributor, and adding some white silicone conductive grease under the module, and screw it back down.
see what happens...then check to see if you have any previously stored engine codes that might give you a clue to a impending failure
Thread Starter
Burning Brakes
Joined: Oct 2004
Posts: 898
Likes: 1
From: Pearland Texas
I just got my vaccum and compression gauge in today. Next will be a fuel pressure gauge, I'm attacking this from all angles. I don't want to start throwing parts at it until I'm sure what the problem is. Oh by the way, it ran to and from work OK, but after I parked it, ate dinner, went back out to move it (you guessed it) it wouldn't start.
Its got to be a fuel problem. Will let it set over night and try a start in the morning and do a vacuum check , if it starts. Stay tuned.
Its got to be a fuel problem. Will let it set over night and try a start in the morning and do a vacuum check , if it starts. Stay tuned.
