Sarting Problem Fault Tree

[David T]

With all of the postings recently about people having trouble with hard cold starts, hard hot starts, idling, etc, we should just create a chart to follow for all of this. After fixing these problems continue with a procedure on how to properly set up the idle, all of the adjustments, and setting the mixture. That way instead of reposting for each individual we could just send them there. This is happening with every new owner that is trying to get their car running as it should. It would also save having to search and read through all of the past postings about this and standardize troubleshooting. Every summer we also get the questions all over again about the A/C. And doors.
David Teitelbaum

[Spittybug]

+1 We do rehash old ground a lot......

[Ron]

I think that is an excellent idea!

I'd suggest it be geared to most likely problem(s) learned from experience as possible while being exhaustive -- otherwise, a link to the manual would do as much good in most cases, imho.

[Spittybug]

The a/c problem fault tree in the manual isn't a bad model to use.

[Ron]

I like trees. :devil:

[Farrar]

Here's a check list to get you started for "hard to start while engine hot" conditions. This is a list from the Haynes FI techbook with sensors omitted which aren't on our cars (e.g. MAP, MAF).

- battery discharged or low
- air filter clogged
- PCV valve stuck open
- vacuum leak
- defective coolant sensor or circuit
- corroded battery connections
- bad engine ground connections
- worn or fouled spark plugs
- fuel pressure incorrect
- insufficient residual fuel pressure
- airflow meter faulty
- cold start valve leaking or operating continuously

[Rich]

With all of the postings recently about people having trouble with hard cold starts, hard hot starts, idling, etc, we should just create a chart to follow for all of this. After fixing these problems continue with a procedure on how to properly set up the idle, all of the adjustments, and setting the mixture.

Until we get that going - and it IS a good idea to create a new Resource as proposed - there is still this factory-sourced information in our Resources forum we can look to.

4 pages of the DMC Tech Manual HERE: Engine-Will-Not-Start (http://dmctalk.org/showthread.php?3142-Factory-Troubleshooting-Charts-Engine-Will-Not-Start) showing 5 progressive troubleshooting steps in each of two categories.


A 2-page guide for Ignition + a 2-page guide for Fuel.

There is a related page with a more expanded set of engine conditions than "Will Not Start" HERE: Engine Diagnostic Chart (http://dmctalk.org/showthread.php?3143-Factory-Engine-Diagnostic-Chart) but not with a tree. Covers 14 conditions, including Poor Idle, Misfiring, Poor Warm Start.


It is a list of possible causes of each engine condition. Sometimes there will be multiple conditions on a car and by checking THIS table one can look for a common cause/component.

Click-magnify the images at those links to bring them up clearly.
If somebody is taking on the proposed Fault-Tree project and if this DMC-sourced info in the links is correct then it might be a good basis with which to start the proposed new document.

[David T]

We can do a lot better than the manuals because we are seeing right here real world experience. We see what is common and we also see the effects of age and neglect and PO's modifications. The manuals were meant for techs with some automotive background. Most newbies don't have that. Heck, they can't find the hot start relay socket! If they DID read the manuals they wouldn't be asking half the questions they do! They come here looking for the easy way out like we have a Magic Wand or something. I just think having a procedure (a road map) we could send them there so some of them could maybe find some problems on their own. At the very least they would better understand what we are telling them to do. As a for instance, they replace the mixture unit. They mix up the feed and return and now it won't start. That has happened a couple of times. Same with the fuel pump hoses. Where is that in the manual? The no start won't tell you the connections on the ballast resistor rust and will cause a no-start. So will a car wash when you have cr-ppy ignition wires or decide the motor would look better if it got power washed!
David Teitelbaum

[Ron]

Agreed!...........Well let's do it!

[David T]

Getting down to the nuts and bolts of exactly how to do it is my problem. I have all of the knowledge but I am sure it would come out better as a collaborative effort by the whole group, something like Wikepedia so everyone can improve it. As a way of getting started we should choose a relatively simple and short topic and then build on it. Like what to do on the first day after you have dragged your new treasure home after sitting for XX years in a barn.
David Teitelbaum