Diagnostics

[mattboyrd]

Does anyone know of a good book or website that will list basic performance issues and set you on a path to correct them?
I'm thinking something along the lines of the old VW idiots guides. Those things were a godsend when I was driving vee dubs.
Dwelling and driving in an 89 Dodge van now and it's getting temperamental and it's one of those weird problems to pinpoint

 

[SternWake]

Does anyone know of a good book or website that will list basic performance issues and set you on a path to correct them?
I'm thinking something along  the lines of the  old VW idiots guides. Those things were a godsend when I was driving vee dubs.
Dwelling and driving in an 89 Dodge van now and it's getting  temperamental and it's one of those weird problems  to pinpoint

I've an '89 dodge for 14 years now.  What's it doing?  Any computer codes stored?

 

[SternWake]

You can pull the computer codes by turning the key to On and off twice then back to on and leave it on.

Watch the check engine light. It will go out, then start flashing. two flashes, a pause then 5 flashes is a code 25.

Expect to see a code 12, and a code 55. Post any other codes, and symptoms.

Code 55 will be flashed last as an 'end of codes'

 

[highdesertranger]

assuming your maintenance is up to date, correct? what's is the problem? stern knows his van intimately, he has pointed out some computer issue that are very common for dodges. highdesertranger

 

[mattboyrd]

Right now, I'm assuming she's just in need of a tune up. Slight hesitation and minor back fire on acceleration which can be avoided by light and steady acceleration. Usually.
Noticeable loss of power when climbing steep Hills.
Exhaust smells like air fuel mix is off too so an ecm check is probably in order as well.
I think I've got this problem well in hand but am looking for a book or site that will help me diagnose more complex issues should they arise in the future.
I've got a Chiltons manual for it but it worthless for diagnostics.
Thanks for the answers so far.

 

[mattboyrd]

P.s.
Thanks for the code trick and info. I'll check that out.

 

[mattboyrd]

12 and 55.
I checked plugs points etc... All seemed to be doing their thing and in good shape. From the recent maintenance history given to me when I bought her in Feb of this year, everything should be well within their working lifespans.
She runs fine at idle and when revving in Park or neutral and when moving at consistent speed. Just acts up under load once it starts to get warmed up.
I think I'm just going to replace everything and go from there.

 

[Almost There]

12 and 55.
I checked plugs points etc... All seemed to be doing their thing and in good shape. From the recent maintenance history given to me when I bought her in Feb of this year,  everything should be well within their working lifespans.  
She runs fine at idle and when revving in Park or neutral and when moving at consistent speed. Just acts up under load once it starts to get warmed up.
I think I'm just going to replace everything and go from there.

Just because I'm way curious when something runs fine when cold but not once warm I used my friend Google!

Here's something that might just be of interest to you:

http://autorepair.about.com/cs/faqs/l/bl654h.htm

A known problem caused by new wires not being routed properly causing the coil wire to be too close to the spark plug wires.

Worth checking out IMO.

The first thing I thought of though when you mentioned running rough under load once warm was a hairline crack in the distributor cap...it's one of those BTDT things.

 

[GotSmart]

This always worked for me if everything else was done recently.  A clean fuel system is the first thing I tried.

http://lucasoil.com/products/fuel-treatments/lucas-fuel-treatment

 

[c_hasbeen]

If you are getting hesitation when accelerating like from a stop sign or what ever but can kind of ease into the gas pedal and gently and slowly get the engine to accelerate you may have an accelerator pump gone bad on your carburetor.
if so turn off the engine so is not running take off the air breather and look down in the top of the carb, open the throttle with your hand as you do so and watch to see if two little streams of gas are squirted into the carb. These should be strong like from a water gun when you were a kid, if so than this is not your trouble but if they are just kind of drizzling in or not at all than your little pump on the front of the carb is gone out, it is not very expensive and quite easy to replace with a screwdriver.

this is the first thing I would check.
good luck

 

[user 2252]

The very first thing to check is the mechanical condition of the engine, new distributor cap and spark plugs will do no good if you have a bad valve, ect, ect. check compression first with a compression tester, then check timing chain wear by turning by hand the crankshaft in the normal direction with the distributor cap removed. line up the timing marks then, watching the distributor rotor, turn the crankshaft in the other direction and measure by timing marks when the rotor moves. Good Luck!

 

[Almost There]

The very first thing to check is the mechanical condition of the engine, new distributor cap and spark plugs will do no good if you have a bad valve, ect, ect. check compression first with a compression tester, then check timing chain wear by turning by hand the crankshaft in the normal direction with the distributor cap removed. line up the timing marks then, watching the distributor rotor, turn the crankshaft in the other direction and measure by timing marks when the rotor moves. Good Luck!

Welcome Back Sir!!

Not only up and walking but posting on the board...

 

[wayne49]

Back in the day (1967), runs fine cold, but not when hot, the first thing to do was replace the coil. 

Cheaper than an ECM.

 

[highdesertranger]

welcome back von brown. glad to see you posting. couple of things I have seen posted that I want to correct, an 89 dodge does not have points or a carburetor. I tend to agree with von brown, do a compression check. if you are getting popping under hard acceleration it sounds like a valve issue. could also be a crossfire issue. highdesertranger

 

[c_hasbeen]

Interesting about the carb, I had a 89 dodge pickup and so did my dad, both had carbs, I suppose these may have been swapped in at some point before we became the owners.

when did they go to fuel injection ?

 

[GotSmart]

That generation van has TBI.  (Throttle Body Injection)  Keeping the fuel system clean keeps a huge nightmare of parts and fine tuning problems from happening with that system.  A vacuum leak in one of those tiny plastic lines will cause high end running problems.

Ask me how I know.

Those coils are good for 100K miles.

 

[66788]

There are two temperature sensors on the intake manifold. The one on the front left as determined while sitting in the driver's seat is for the computer. The other is for the gauge. Mine had a bad computer temperature sensor and did that.

Get the factory service manual from ebay and there are simple tests for all the electrical sensors. This saves guessing and buying parts you don't need.

My 89 started out running like crap and now runs like a brand new van. Clean tailpipe, no black inside, just clean metal.

 

[Canine]

First things first.Read the codes.

 

[SternWake]

I had those same symptoms twice, both times it was spark plug wires.  They degrade quickly under the dog house..  They should not be touching each other or anything metal which is grounded.  Returning the dog house to position can also push the wires down onto something grounded or to each other and cause misfiring too.


The two wire coolant temp sensor will not throw a code until it is way out of parameters, however it will screw up the AF mixture.

Same for a Lazy 02 sensor, no codes but bad driveability.  Use NTK or Denso, not Bosch, in a dodge.  NTK is OEM.

More recently I cleaned every sensor connector with Caig Deoxit d5 spray and some micro swabs.  The 02, Map and TPS sensor connectors were extremely oxidized despite the vast amount of dielectric grease in them.

When i was done it felt like I took 500 LBS out of the Van.  The Deoxit product can do what no other contact cleaner can do, which is remove the oxidation on the conductive surfaces.  Other cleaners leave a pristine oxidized surface.

Backfiring through the throttle body can be timing related too.  either spark timing as controlled by the ECM, or a worn timing chain.

 

[mattboyrd]

Thanks to all for the tips and suggestions! Glad I joined this community forum.
Unfortunately I was without wifi for a couple of days and didn't see the last few replies til now.
Fortunately though; the new plugs, wires, distributor, rotor, and air filter did the trick. She's running great again.
I had intended to do a compression check as I went through the plug r&r but forgot to buy a gauge when I was at the store and didn't remember til I was on the 2nd plug. Luckily all 8 plugs were the hoped for light tan but were all roughly. 005 over gapped.
Thanks again folks.