92 APV fuel injector causing engine to die

[AJ&J]

Our 1992 3.8L van has been dying due to loss of spark for about a week. It finally got bad enough and lasted long enough to determine the loss of spark being the cause. It only dies when it gets hot - not overheated. If you let it cool it will start again. We replaced the ignition module with no change in the problem. We took it to a backyard mechanic with a scope who told us that there is a problem with the resistance in the fuel injectors and when the engine heats the computer is shutting off the spark due to a change in the injector resistance. He recommended changing all 6 injectors. Now, I have a parts from a 3.8L engine that was in an unfortunate accident, so I don't have to buy the injectors, but this sounds odd to me. Does anyone else have some knowledge about this problem?
Thanks, AJ

[LMP]

Crank position sensor failure is generally associated to this kind of symptoms: an exact match. At that age, it IS an almost compulsory maintenance item. I would not risk going far from home without a new one installed even it if worked.
Details:
www.avigex.ca/xport/ckps.jpg
www.avigex.ca/xport/ckpphoto.jpg
www.avigex.ca/xport/ckpulley.jpg
www.avigex.ca/xport/cksphoto.jpg
MOst annoying is getting the crankshaft bolt out: it DOES unscrew the normal way (antoclockwise) but you will probably need a high impact tool: I used a 3/4 drive sicket. NO need to block the flywheel . Then you have to find a puller that will fit to get that balancer pulley out. ONce done you're happy, but at times you might have thought it would never come....
..and disregard the injector replacement cue: really out of scope. CPKS failure can also fail the trig to the injectors..which was my case last year, while I still had spark: confusing at best...

[AJ&J]

Originally Posted by LMP

MOst annoying is getting the crankshaft bolt out: it DOES unscrew the normal way (antoclockwise) but you will probably need a high impact tool

Funny you should say that. We have had this van for 7 years and have had very little problems in that time. This summer has been a different story. About a month ago we had the harmonic balancer come apart on it. Had a tough time to get the bolt out so I put a breaker bar on it and made sure the area was clear of things a people and bumped the ignition. It loosened it just slick. After it was replaced, it ran great until this came up. I considered replacing the crank pos sensor then and probably should have. Thanks for the advice.
AJ

[LMP]

Originally Posted by AJ&J

...I put a breaker bar on it and made sure the area was clear of things a people and bumped the ignition. It loosened it just slick.

WOW....I just exploded in laughs ...a really good one I did not think of : clever.
By the way, I long to see a photo of a balancer that came apart. THis has been mentioned many times but I'd like to have a cue about where to look for signs of desintegration.....

[Android_Gimpy6456]

The whole bump thing is a sweet idea, how come I never thought of that... I always ran a bar through the wheel to the hole in the crank pulley. Sometimes I had to bend it a thousand times to get it too work but it did.

[AJ&J]

Wow, this van is still down. Here is a list of repairs.

The Crankshaft position sensor was replaced - no help.
The TPS kept coding so we replaced that one with new parts -no help

A mechanic told us to replace the MAF sensor, We used a part from the wrecked van and it helped for a while. Then the MAF sensor burned up again and we were back to square 1.

Then we started looking at the electrical side of things since the MAF diode was burned black. Found a fuse that was melted but not blown that was connected to the auto starter. I proceeded to remove the auto starter.

I am now replacing the PCM and the ECM from the wrecked van and of course will need to replace the MAF again, but I think this may finally be the ticket.

Here is a picture of the harmonic balancer that came apart. Click on the thumbnail.




[IMG[/IMG]]http://www.automotiveforums.com/vbulletin/[/IMG]

[RVTRichard]

Hello;
I read your problem and it's the same as mine. I have performed the following with out any success.
Below is a list of things I have changed but still has not fixed the problem.

Plugs & wires
Fuel Filter
Oxygen Sensor
MAF sensor
Air Intake Temperature Sensor
Ignition coils
Ignition Module
Crankshaft sensor
Computer
EGR valve

I think I'm going to try the fuel injectors next.

[RVTRichard]

As of today I have not yet solved it. I now suspect that it may be the plastic intake manifold. If I beat this thing I'll post the outcome.

[LMP]

Excellent thread about upper plastic here:
http://www.automotiveforums.com/vbul...d.php?t=401247
but this is about the series 2 3800, never used in the van. It would be something new to document a similar case for a series 1...

and thanks to AJ&J for the balancer photo....