Hot start but with rest pressure

[bytes311]

Hey guys,

My car started exhibiting this behavior after my last two drives:

Car fires up every time when cold, but struggles to start when warm - and it happens immediately after engine shutoff (~10 seconds between shutoff and startup). If I crank within a couple seconds after shutoff, the motor stumbles and catches (sometimes). I disconnected the blue plug from the CSV but it made no difference.

I have confirmed that there's rest pressure on the air plate. In fact, pressure remained 24 hours AFTER my last drive. Does this sound indicative of a pinched or a kinked fuel line somewhere? My fuel pump is about 2 years old, and my fuel accumulator + fuel filter are less than a year old.

Thanks

[Bitsyncmaster]

That is a rare problem to not restart after 10 second shut down. Have you adjusted the mixture via the dwell reading when the engine has warmed up?

[bytes311]

That is a rare problem to not restart after 10 second shut down. Have you adjusted the mixture via the dwell reading when the engine has warmed up?

Hmm, I did adjust the mixture when warmed up about a month ago using a dwell meter because the needle swung outside the ideal range.

[Michael]

Something has recently changed...I bet the mixture is off but because a new vacuum leak has developed somewhere. You should put a meter back on it and see where you are at(don't adjust anything) just see what it's doing.

Maybe on a cold engine, really get in there and look/feel aroud for a broken/split line.

Also don't discount a bad check valve at the fuel pump or broke o-ring on the fuel dist.

[David T]

Something has recently changed...I bet the mixture is off but because a new vacuum leak has developed somewhere. You should put a meter back on it and see where you are at(don't adjust anything) just see what it's doing.

Maybe on a cold engine, really get in there and look/feel aroud for a broken/split line.

Also don't discount a bad check valve at the fuel pump or broke o-ring on the fuel dist.

I suggest you check initial base timing, mechanical, and vacuum advance. Also check the connections on the ballast resistor and the bypass relay. If it has been a long time, clean and regap the park plugs.

[bytes311]

Something has recently changed...I bet the mixture is off but because a new vacuum leak has developed somewhere. You should put a meter back on it and see where you are at(don't adjust anything) just see what it's doing.

Maybe on a cold engine, really get in there and look/feel aroud for a broken/split line.

Also don't discount a bad check valve at the fuel pump or broke o-ring on the fuel dist.

A vac leak or collapsed fuel line could be the case. Another thing I noticed is if I step down on gas pedal to the floor, the motor hesitates like it doesn't have enough fuel to accelerate, and then "pops' at the air plate.

[sdg3205]

If you're hearing those pops then yes, I agree it sounds like a fuel/spark issue. The "PRV Pop!"

[bytes311]

I just checked all of my fuses and discovered #7 had a dark coating on one of the blades. I swapped it with #15 (I don't have any spare fuses at the moment) and the car fired up like nothing was wrong. The online documentation shows that #7 fuses Lambda components, the FV, and CPR. I hope I didn't damage anything if all this time it was the fuse.

[sdg3205]

I just checked all of my fuses and discovered #7 had a dark coating on one of the blades. I swapped it with #15 (I don't have any spare fuses at the moment) and the car fired up like nothing was wrong. The online documentation shows that #7 fuses Lambda components, the FV, and CPR. I hope I didn't damage anything if all this time it was the fuse.

If your lambda system was disabled the car would run like crap. Maybe even barely run. U may have found your smoking gun, but the fuse also powers the fuel pump, which was obviously running, so maybe not.

[Morpheus]

This behavior could also be indicative of a dying fuel pump. My car would occasionally do the same thing, until last weekend when it just stopped running. I have the newer style DMCH pump, and it is about 4 years old. I traced the issue to the fuel pump, which is getting power but is completely dead.

Luckily, the internal pump component is replaceable for about $100.