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Car question

stinkyboy

Plastic Santa
Jan 6, 2005
15,187
1
¡Phoenix!
Plugs/cables are fine, fuel pump is fine, distributor/cap/rotor are new, but I'm not getting "a full start". It will start, but I can't get gas to the system, and it idles like it's badly out of time. Any guesses?
 

dfinn

Turbo Monkey
Jul 24, 2003
2,129
0
SL, UT
stinkyboy said:
I don't think so, the injectors are getting plenty of fuel. My VW mechanic buddy is talking about maybe a bad computer?
what kinda car we talking about here. if it's a newer car could be something stupid like a sensor not working and the ecu keeping the car from starting.

edit: you getting spark?
 

dfinn

Turbo Monkey
Jul 24, 2003
2,129
0
SL, UT
re-read your description. sounds to me like you aren't running on all cylinders. check firing order like wumpus said. If that seem right then try to isolate which cylinder(s) isn't firing (assuming that's the problem), this usually is pretty easy to do. Start the car up, let it idle, unplug the wire to each spark plug one at a time. The plug that you pull that doesn't seem to have any effect on the way the car is idling is the problem one.
 

stinkyboy

Plastic Santa
Jan 6, 2005
15,187
1
¡Phoenix!
dfinn said:
re-read your description. sounds to me like you aren't running on all cylinders. check firing order like wumpus said. If that seem right then try to isolate which cylinder(s) isn't firing (assuming that's the problem), this usually is pretty easy to do. Start the car up, let it idle, unplug the wire to each spark plug one at a time. The plug that you pull that doesn't seem to have any effect on the way the car is idling is the problem one.

Good idea! Thanks!
 

Ciaran

Fear my banana
Apr 5, 2004
9,839
15
So Cal
stinkyboy said:
I don't think so, the injectors are getting plenty of fuel. My VW mechanic buddy is talking about maybe a bad computer?
It's not a Jetta is it?
 

Potroast88

YouTube Boy
Jan 18, 2004
2,834
4
Bomb City
dfinn said:
re-read your description. sounds to me like you aren't running on all cylinders. check firing order like wumpus said. If that seem right then try to isolate which cylinder(s) isn't firing (assuming that's the problem), this usually is pretty easy to do. Start the car up, let it idle, unplug the wire to each spark plug one at a time. The plug that you pull that doesn't seem to have any effect on the way the car is idling is the problem one.
I don't think Stinkyboy is running on all cylinders.
 

stinkyboy

Plastic Santa
Jan 6, 2005
15,187
1
¡Phoenix!
SkaredShtles said:
Aren't you the guy who bought the POS Toyota van in some vain hope that you could make it into the ultimate shuttle?

Maybe you should just get rid of internal combustion vehicles.................
That was an ordeal. I couldn't give that thing away! The title was a little sketchy. I finally left it in a parking lot with the keys in it and posted on Craigs List a FREE van, and it hasn't been seen since...
 

Reactor

Turbo Monkey
Apr 5, 2005
3,976
1
Chandler, AZ, USA
Could be an O2 sensor. If your VW mechanic friend can talk to the computer and see.

Some cars (Dodge and some others) have a sequence of ignition on/off clicks that will force the computer to blink a dash light in a code. You can take the code and find out what's wrong. You can probably google it out os a VW forum if VW's do the same thing.
 

dfinn

Turbo Monkey
Jul 24, 2003
2,129
0
SL, UT
Reactor said:
Could be an O2 sensor. If your VW mechanic friend can talk to the computer and see.

Some cars (Dodge and some others) have a sequence of ignition on/off clicks that will force the computer to blink a dash light in a code. You can take the code and find out what's wrong. You can probably google it out os a VW forum if VW's do the same thing.
They don't, not to my knowledge anyways. I believe if it's any newer than 1995 then you will be able to connect to the ECU and check it for codes using an OBD1 or OBD2 (depending on the year of the vehicle) scan tool. I've heard places like autozone and pep boys will usually do this for free.

edit : I also think it's highly unlikely that it's an O2 sensor. They can cause issues with how your car runs but I've never heard of them keeping a car from starting. I've known people who have driven around for extended periods of time with the wire to the O2 sensor disconnected.
 

Reactor

Turbo Monkey
Apr 5, 2005
3,976
1
Chandler, AZ, USA
stinkyboy said:
and it idles like it's badly out of time.
Sorry, I pretty much zoomed on this part, A bad O2 sensor that rails in the "too rich" condition will force the car to lean the mixture all the way down. I had a car do this and it was almost completely undrivable.
 

Palilla

Monkey
Jul 20, 2004
102
0
It sounds like the timing could be off. What kind of vw motor is it? Most vw motors need to have the timing checked in three locations.

Other things to check:

1. Compression test on all cyclinders to see if everything is even.
2. Check the condition of your plug wires, they may appear to be ok, but when running they might arc onto your manifold causing the rough ideal/hesitation.
3. You changed the rotor/cap, but did you check the coil? The vw guy i go to shots his with a little water to see if it sparks. They are known develop small cracks pretty easily.
 

Palilla

Monkey
Jul 20, 2004
102
0
Also, bad O2 senser's shouldn't effect the idle that badly, especially at start up and they shouldn't fail to the point that you can't drive your car (they are not designed to do this). Typically when they go bad you may notice your car is more sluggish at top end, and your mpg will be worse.
 

Biscuit

Turbo Monkey
Feb 12, 2003
1,768
1
Pleasant Hill, CA
If you've got one, MAF (mas air flow) sensor.
Computer misreads how much air the car is getting and adjusts the amount of fuel too rich or lean.
 

stinkyboy

Plastic Santa
Jan 6, 2005
15,187
1
¡Phoenix!
I think Reactor is an O2 sensor salesman...

It's a 92 Jetta GL 1.8, 8valve, and sadly, the computer is no help on this older car. I just talked to my buddy and he went to the junk yard and is swapping out parts one by one to figure this out. He's pretty experienced and only works on VW's, but this has him stumped. He'll be pissed if I take it to a dealership...

I'll suggest your suggestions Palilla. Thanks!
 

Reactor

Turbo Monkey
Apr 5, 2005
3,976
1
Chandler, AZ, USA
stinkyboy said:
I think Reactor is an O2 sensor salesman...

It's a 92 Jetta GL 1.8, 8valve, and sadly, the computer is no help on this older car. I just talked to my buddy and he went to the junk yard and is swapping out parts one by one to figure this out. He's pretty experienced and only works on VW's, but this has him stumped. He'll be pissed if I take it to a dealership...

I'll suggest your suggestions Palilla. Thanks!
Dang! you're on to me!! :sneaky: Actually it could be anything affecting how the car computes the fuel mixture. Your buddy sounds like he should be able to figure it out. Good luck.
 

Sandwich

Pig my fish!
Staff member
May 23, 2002
21,030
5,918
borcester rhymes
stinkyboy said:
it idles like it's badly out of time
is it timed properly? If you're getting spark, and you're getting gas, your car should start. It won't start if it fires either in the improper order, or if the distributor is not properly aligned.

Therefore, make sure the first piston is at TDC, and that the distributor is also lined up at TDC. There should be a mark or something. On older cars, you can adjust the dist. to alter timing just a tiny bit. It's enough though, and if your dist. is completely installed wrong, you'll get symptoms similar to yours.

Is the gas in the car good? If it's old, you may need to drain the tank, replace the filter, and fill it with dry gas/good gas. Also, are your fuel injectors clean?
 

Sandwich

Pig my fish!
Staff member
May 23, 2002
21,030
5,918
borcester rhymes
edit:
i see you say you can't get gas. If the fuel pump is good, check the filter. If that's good, it's your injectors. Make sure the connectors are clean, and if possible, have the injectors flowed to ensure they're still good.
 

zahgurim

Underwater monkey
Mar 9, 2005
1,100
12
lolAsia
My old VW did the exact same thing once... it ended up being that one of the vacuum lines coming out of the air sensor box had a small leak/tear in it. Was a bitch to find, but was an easy fix.

Check all your little air hoses carefully.
 

SkaredShtles

Michael Bolton
Sep 21, 2003
65,375
12,529
In a van.... down by the river
zahgurim said:
My old VW did the exact same thing once... it ended up being that one of the vacuum lines coming out of the air sensor box had a small leak/tear in it. Was a bitch to find, but was an easy fix.

Check all your little air hoses carefully.
And if it's a vacuum issue, you might be able to spray starting fluid around and narrow down the location.........
 

rooftest

Monkey
Jul 10, 2005
611
0
OC, CA
Sandwich said:
is it timed properly? If you're getting spark, and you're getting gas, your car should start. It won't start if it fires either in the improper order, or if the distributor is not properly aligned.
:stupid:

I'd bet your timing is off.
 
J

JRB

Guest
Sandwich said:
edit:
i see you say you can't get gas. If the fuel pump is good, check the filter. If that's good, it's your injectors. Make sure the connectors are clean, and if possible, have the injectors flowed to ensure they're still good.
He already told me it couldn't be the filter. I gave up. We're on a forum for krissakes. How the hell can we diagnose it???
 

stinkyboy

Plastic Santa
Jan 6, 2005
15,187
1
¡Phoenix!
johnbryanpeters said:
We can suggest that sb quit screwing around and hire a competent mechanic...
He's just been swamped as he is sponsoring a VW run up to Jerome, AZ this weekend
(Great little town) and he's got around 25 rides he's working on.

But everyone can rest easy now as the problem turns out to be the ignition coil.

Thanks for the input monkies!
 

stevew

resident influencer
Sep 21, 2001
40,494
9,525
stinkyboy said:
He's just been swamped as he is sponsoring a VW run up to Jerome, AZ this weekend
(Great little town) and he's got around 25 rides he's working on.

But everyone can rest easy now as the problem turns out to be the ignition coil.

Thanks for the input monkies!
I take it you have seen these stickers if you are in AZ....