A year ago the distributor failed. I replaced it and re-set the timing (disconnecting the wire near the ac compressor when doing this as instructed to do). I set the timing as exact as possible but when pushing the throttle, the timing position moves a lot. I've heard that when the wire is disconnected, and the timing is set correctly, the mark shouldn't deviate much, if at all.

Until I replaced the distributor, the car ALWAYS started instantly every time without fail...

Since I changed the distributor and checked and double checked timing, the car runs pretty good and starts perfect cold but is very hard to start hot... and it's costing a lot more in fuel (it's about $6/gallon in UK so I gotta fix it!) -also I just had to replace the cat which i hear can be caused by bad timing)

-I know it's something to do with the timing one way or another, could it be the chain??! (it's not been changed) but if the car was good before changing the distributor, wouldn't it be better after, not worse... people tell me it could be timing chain but it just doesn't make sense (to me).

I want to be real sure about the timing chain as I hear it's a real pain to swap and don't want to make things worse.

-it's a 305 TPI by the way

thanks

 

the timing mark should move as you increase the rpm. if it was all good before the swap my guess is your problem lies in something you swapped.

 

did you get a brand new distributor, or a junkyard distributor (would be surprised if you could find any in a junkyard in the UK... does the UK even have junkyards? LOL)

 

Hot starting problems usually occur on a car with headers where the starter solonoid experiences heat soak. What is your timing set at right now?

 

Ok yea the soleniod on the starter will get warm from headers, but the problem with gM starters is they dont have the ***** to turn over a motor with any above factory amount of timing and compression....ESPECIALLY when the motor is hot....

im was using my stock starter (91LB9) on my now 10.8 LT4 motor with 12 degress initial and when hot it wouldnt spin it as fast..

then i switched to a LT1 mini-hi torque starter and no matter how hot the motor or solenoid for all you guys that want to hear that got it would spin it just as fast at 195 as it would on a cold start


the heat on the solenoid isnt the problem...its having to much initial timing and the starters lack of ***** is prevent it from turing over fast enough...check your base timing

 

thanks guys...

I need to check what I set the timing to (I can't remember -but it was the specified one for that model... from memory +6 ?? -but I need to check, I really can't remember so don't freak out if that's wrong -I'll check!)

I don't think it's the starter as it "sounds" like it's starting strong (the starter doesn't sound weak" -the engine just turns over and doesn't do anything for about 10 seconds unless I push the throttle hard. Normally, until I changed the distributor it starts in a second or less -straight away. It still does, when it's cold. The weird thing (this might help you figure out the problem) -it starts hot if started within about 30 mins of switching offf…. but if I leave the car a few hours, then it's really hard to start (so a "warm start" issue!) -when it does start like this, it almost sounds like it's starting "off-beat" -hard to describe… but starts kinda like a lawnmower like this! Again, once it's running, it "sounds" perfect. (but I think whatever's wrong is wasting fuel/ruining the cat)

Course we have junk yards! -but next to no firebirds (Pontiacs have never been officially sold here -they're all special imports).

It is a complete new distributor & cap -the MSD model specifically for that engine. It definitely started this hot start problem after the distributor was changed… but I get no backfiring or run-on problems at all… (and no hesitancy etc -though seems just the same power as before I changed to all the MSD stuff -is it just me, or does it make no difference?!)

I checked the timing twice since and it's not changed. Someone told me the timing mark shouldn't move when the thottle is pushed (when that wire -brown wire was it?) is disconnected. Someone else told me to change the timing belt… but I can't see how it could be this if it started once the distributor was changed??

thanks again -any ideas welcome!

 

sounds like a cat to me actually. When you have a cold start your AIR tubes do the emissions (if i remember correctly) until your cat warms up enough to properly do it's job.

When you start it hot the cat could be giving your car so much backpressure that it makes it verrry hard to start the car, but once you get the car started it has a steady flow of air going through it, and so until you get on it, it doesnt show any signs of going out.

A cat can give you horrible gas mileage, the rich thing could be something different all in itself, but it's also possible that the cat isnt working properly and is just spewing out old gas instead of breaking it down in the cat, making you think that it's running so rich. That was my problem when I got my car.

If you have a welder and torch you should try taking off your cat, and try running your car for a while like that, drive it around for like 30 mins, maybe up two cities and back, then try to start it in your driveway.

 

ok thanks -the cat is only about a month or two old though -I changed it. But sometimes when I start the car (particularly hot) -the exhaust "sounds" blocked and stalls (can't be the cat as it's practically brand new) -this is an occasional thing...

By the way, when hot, the exhaust smokes a bit (black smoke) -only on start though -no other time. Could leaking injectors cause this problem?

Arghghg -I still think it could be something to do with distributor... as that's when it all started... oh I changed the spark leads then too... they might be getting a bit hotter due to the routing round the engine -could hot spark leads make it hard to start?

thanks...

 

The distributor/ignition module have some built-in advance for "limp home" mode. So, even with the wire disconnected, the timing will advance some with increased RPMs. Therefore, make sure the RPMs are low when you set the timing. Otherwise, it'll dog on you.

If it all started (so to speak) when you changed the distributor, you may have gotten a weak unit.