Cold Start 3.0L

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Oct 9, 2014 | 12:34 PM

mediaman67

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Laughing Gas

Joined: Nov 2005

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Cold Start 3.0L

Hi All,

been posting a lot lately, but Van is starting to give me some grief :-)

1989 Shorty, 3.0L (only engine they made that year)

I have a cold starting issue - used to be more of a problem in the winter, but now even if it's 70 degrees outside, she stumbles and then will start...

if I poke the gas while she is trying to start, she gets to normal really quick... sometimes she will on her own, and sometimes she stalls... but if she stalls, and I try to start again, she fires right up...

My guess is that this points to fuel, but I dont want to start replacing stuff blindly - or vacuum? - but why only when she is cold (like 8 hrs+ cold)

if I only rest her for 2-3 hours, no issue, starts fine... it's that early morning thing, sits overnight...

Any ideas? - other than this, the engine runs great still! - very minor tick for 2 mins, then gone... but she has good Oil Pressure still, etc...

Thanks

Oct 10, 2014 | 03:55 AM

96_4wdr

Post Fiend

Joined: Apr 2005

Posts: 5,720

Likes: 5

From: Washington state

Pull the codes.

Is the spark and compression up to specs. Nice strong blue spark with NO yellow on cold crank that will jump 1/2"? 120 psi cold crank compression minimum and less than 10% variation on 6?

Probably the ECT failed, not telling the engine the correct coolant temp for cold start, no enrichment.
BUT, confirm with codes or measuring cold resistance of ECT sensor.

Can also be the AIT sensor, but far less common, not as much effect on cold start enrichment.

If not any of the above, then check cold fuel pressure key on.

Oct 10, 2014 | 07:15 AM

mediaman67

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Laughing Gas

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Im sure the compression and spark are ok... Im almost thinking it's something easy like an old fuel filter, since I haven't replaced it in 20 years... but I would think that would rob me of power on the hwy, etc...

and, if it was that, Im sure it wouldn't matter if the engine was cold or hot... a fuel restriction is just that....

it is fixable right away, but it's just an annoying problem - there are no codes stored as I can see, as I get no dash light, but this is OBD I so, go figure... - I actually do have an OBD I scan tool but I need the right plug for it to work... can I use the Chevy paper clip trick?

what would cause low fuel pressure, only when COLD?

Also, the idle is not as smooth as it used to be, but that could be old leaky vacuum lines, and 20 other things Im sure - she never stalls, but she used to idle almost like glass at one time. living with that... not like she shakes the whole van at idle or anything like that at all... you can feel it in the steering wheel though for sure - random misses almost - timing is fine...

Thanks

Oct 10, 2014 | 07:17 AM

mediaman67

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Laughing Gas

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I can post a video of what I mean - where do people post videos on here? - of do I link it to my youtube channel?

Oct 10, 2014 | 10:51 AM

87&97Aerostrar

Senior User

Joined: Aug 2014

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From: Florida

Tomorrow morning try turning the key to the run position for a few seconds before trying to start it.
As for your idle issue, try cleaning the throttle body.

Oct 10, 2014 | 11:08 AM

mediaman67

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Laughing Gas

Joined: Nov 2005

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yeah, that did make a difference usually -but I still would like to fix the problem if possible - but I guess I could just live with it.

Oct 10, 2014 | 12:52 PM

87&97Aerostrar

Senior User

Joined: Aug 2014

Posts: 269

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From: Florida

If the key thing works it means your fuel system is losing pressure overnight and your 25 year old fuel pump takes a second or two to pump it up. My 97 does that and since I don't have any leaks, I guess there's a faulty check valve somewhere in the system that's letting the pressure bleed down. Not worth fooling with.