Engine won't start unless I wait!!

[mongoosetoo]

When I start the GNutlass (85 GN) it fires right up. If I shut it off and try to restart, I have to wait at least 20 minutes. Sounds like a coil or ignition module???

This problem just a started after I put a cold air intake on the car and rewired the electric fan. The only rewiring I did to it was use the coil braket as a ground for the temp switch.

Since the engine does not have a provision for a temp switch to control an electric fan or a port for an aftermarket water temp sensor, I made one. I used a pipe the same diameter as the upper radiator hose and welded two bungs on it for the switches/sensors. I also welded a bolt for the ground/mounting bracket. This is how I grounded it, through the framework of the coil bracket. I did not remove the coil or disturb it in any way, I just drilled two holes in the hose support and mounted my bracket to it.

The cold air intake was pretty straight forward. I just removed the old air claener and plumbing up to the MAF then plumbed in my own stuff. I wanted to use aluminum pipe, but only need about 6 inches, so instead I used PVC and painted it flat black and then mounted the new conical K&N style filter to the other end of the pipe. I intend to put up an aluminum barrier wall between the air cleaner and the radiator to draw air exclusively from behind the left headlight. It looks good for cheap. I've got $46 in the filter and plumbing.

Anyway, the car is having problems. One thing I did that was out there a little, is I needed a power source to energize the aftermarket fuel pump relay, so I am using the brake powermaster ( I have vacuum brakes now) to supply ignition power to my fuel pump relay.

One last thing, my ECM will not enter diagnostic mode when I short the pins under the dash.

Thanks, Brew

 

[alec296]

i suggest checking all your grounds and do you have the ground
strap from back of head to firewall? if not put one on.
check your bolt to engine for your main cable also
andy

 

[tenright]

Just a guess but it sounds like your flooding it, are the plugs wet after you shut it off?....is there an overwhelming fuel oder???




T

 

[mongoosetoo]

plugs are not wet, they are perfectly colored light tan. I'll check grounds and get back to you. thanks, brew

 

[mongoosetoo]

When I installed the cold air setup, I must have pulled the vacuum line that leads to the brakes. Anyway, that would explain a lot of issues, its like having a 1/2" hole in your intake.

The car still is hard starting unless I wait 20 minutes.

I also check ed the MAF inlet; it is clean. And I checked the Evap emissions canister. I had moved it for the cold air setup. I thought maybe I pinched the tank vent line - but no luck, the lines were fine.

I'll pull the schematics and check all the grounds in the engine and cabin areas.

Thanks for input, Brew

 

[mongoosetoo]

I grounded the intake manifold to the firewall and still nothing changed. The cylinder head to firewall wire was already installed, so I did the intake manifold as a backup.

The car still starts and runs only after a 20 minute rest. Ignition module maybe???

I'll check all the grounds later - it's really hot in the garage today.

Thanks, Brew

 

[Jerryl]

............ The car still starts and runs only after a 20 minute rest. Ignition module maybe?? .......... I'll check all the grounds later - it's really hot in the garage today.

Does the car die suddenly as in "turning off the ignition"?
You may have a plugged vent in the gas tank cap.
Easy enough to test.

 

[mongoosetoo]

Nope, that's just the thing. It runs great when you start it. You could go to town, come back and shut the car off. Then if you try to start it again, you may get a "pop" or nothing at all. Regardless, it won't start for at least 20 minutes. It never, just plain, dies on me.

Any thoughts? To me, it sounds coil-ish or ignition module-ish. BUT- you could also start the car and let it run for a few seconds, shut it off and same story. You have to wait 20 minutes to start it.

It will be a couple weeks before I can work on it. I'm in Germany for work, be back soon. Just trying to get ideas so I can hit the ground running when I get back.

Thanks, Brew

 

[cool 84]

Bad fuel pump relay? They sometimes quit working once they get hot. Once the engine is running and you have oil pressure the oil pressure switch completes the circuit and you no longer need the fuel pump relay.

Have you tried cranking it over long enough for it to get oil pressure?

Could be cam sensor. Once it's running you can lose the cam sensor signal and it will keep running but won't start back up once you turn it off. This would throw a check engine light though.

 

[Jerryl]

Bad fuel pump relay? They sometimes quit working once they get hot. Once the engine is running and you have oil pressure the oil pressure switch completes the circuit and you no longer need the fuel pump relay.

EXCELLENT! (I will add this to my CRS memory bank)

mongoosetoo Try this:
After you shut the car off, spray the relay with a can of electronic cleaner to cool it off.
If it starts after spraying, you will know for sure.

 

[mongoosetoo]

The relay is brand-new, and not wired in the typical way. I ran a dedicated circuit to the aftermarket relay, the same 30 amp sytle I use for electric fan. Anyway simple circuit...I use ignition power to energize the relay. Currently I use the power source that used to go to the powermaster brake. I also jumped a wire to the grey wire that goes to the stock fuel pump relay. Otherwise the pump gets power straight from the battery through the relay into the pump.

If I remember right, I jumped the grey wire so the injectors would work. Otherwise they would not fire. I'll have to look at my schematic.

As far as cooling the fuel pump relay, I'll give it a shot even though it is aftermarket - it may be a piece of junk! It'll be another week before I'm home to try.

 

[mongoosetoo]

Just thought of something. The relay cannot be bad. All I have is a drivers seat in the car, so I can hear the pump - loud and clear. Good relay.

Keep em coming. Thanks, Brew

 

[Jerryl]

Just thought of something. The relay cannot be bad. All I have is a drivers seat in the car, so I can hear the pump - loud and clear. Good relay.

Keep em coming. Thanks, Brew

As stated by Cool84, You are down to possibly defective cam and crank sensor.

 

[mongoosetoo]

Both of the sensors were new last year. Is it common for them to take a dump? I mean I hate to disagree, but I can't even enter diagnostic mode still. It makes me think something is crossed or not grounded somewhere?!?

 

[mongoosetoo]

Is there any way adding a cold air setup would cause this? I mean I really don't see how, it's just basically take off the stock filter and put on a free flowing one.

 

[Jerryl]

Is there any way adding a cold air setup would cause this? I mean I really don't see how, it's just basically take off the stock filter and put on a free flowing one.

Probably not. Do you know someone you can swap your ECM with for testing?

 

[mongoosetoo]

I have a spare I can try. Also have a spare ignition setup too. I'll do one at a time.

 

[mongoosetoo]

Engine won't start unless I wait _SOLVED!!!

Thanks for all your input, I found the problem.

I was thinking about what Jeryl said:


"After you shut the car off, spray the relay with a can of electronic cleaner to cool it off.
If it starts after spraying, you will know for sure."

I had replied to him saying that I could hear the pump working so it wasn't the relay. I was wrong, I could not hear it! Anyway, long story short...the power source I was using to energize the relay does not always energize. I was using the powermaster brakes feed since I switched to vacuum brakes. I do not know much about powermaster, but apparently the wire I thought was switched power through the ignition switch was not. I believe the computer controls voltage through it.

I ran a dedicated wire to enerize my relay straight to the fuse block, top left labelled IGN. Problem solved.

Thanks everyone, Brew