Truck in question is a stock 99 with a 5 speed. Only mods are a fass lift pump and 1/2 inch lines.

 Like the title says the truck will idle fine and when you give it a bit of throttle it will jusm right to 1400. Nothing in between and nothing over.

My ECM was starting to fail,,,found a good used one along with an injection pump from a cracked 53 block.

Swapped it out today and still the same.

Sort of seems like the APPs but my DRB3 reads the apps and it says it goes from 0 to 100 percent just fine.

Any ideas...

Thanks Chris  

Another little bit of info. The oil pressure gauge goes up at least halfway when I turn key on.  Do some of the other sensors read thru that sensor?

This should help you'll see the sensors on the bottom of the wiring map. Map sensor is up above the ECM. 

5 minutes ago, snowshoveler said:

Another little bit of info. The oil pressure gauge goes up at least halfway when I turn key on.  Do some of the other sensors read thru that sensor?

My temp would peg at key on on s cold engine. Several of the sensoors share the same ground. You can see them in the wiring diagram.

4 minutes ago, dripley said:

My temp would peg at key on on s cold engine. Several of the sensoors share the same ground. You can see them in the wiring diagram.

 

@dripley in your case the gauge pegs because of lack of ground. 

 

@snowshoveler In your case, the P0238 code is most likely a bad ground on the MAP sensor or bad MAP sensor. The P1689 code is worrying me a bit. I would try trading the fuel pump relay in the PDC with like the horn. The weird part is the VP44 is allowing it to start so the fuel pump relay is most likely fine. You going to end up testing the Bus wires between the ECM and the VP44.

Edited March 3, 20187 yr by Mopar1973Man

3 minutes ago, Mopar1973Man said:

 

@dripley in your case the gauge pegs because of lack of ground. 

 

@snowshoveler In your case, the P0238 code is most likely a bad ground on the MAP sensor or bad MAP sensor. The P1689 code is worrying me a bit. I would try trading the fuel pump relay in the PDC with like the horn. The weird part is the VP44 is allowing it to start so the fuel pump relay is most likely fine. You going to end up testing the Bus wires between the ECM and the VP44.

The only time mine did this was when ECM went. Had all kinds of other crap going on too.

Thank you for the help. 

I have a direction now atleast.

I will do what I can with the map sensor first and then proceed to Bus wires between the ecm and vp44...oh I ant gonna like that part  lol

In looking at the schematic. I am a little intimidated by it   ha ha.

For the possible bad ground on the map sensor...where does it ground and what color would the wire be.

Thanks

Map sensor plug...looks nasty to me. 

See if I can clean it up a bit.

Chris

Oh man that plug is horrible, I went through my entire truck and made sure they were all good back in the day and stuffed dielectric grease on all female connectors before plugging them back in.

And here is the sensor...nasty. 

I'm hoping that's your problem, be hard to believe it made good contact. 

That was the issue with the MAP sensor I think....well I hope so. 

A little contact cleaner and a teeny tiny paint gun brush and it looks like new.

1 hour ago, Mopar1973Man said:

 

Hang out here. We'll teach you from a distance... 

You betcha!

That was the issue with the MAP sensor I think....well I hope so. 

A little contact cleaner and a teeny tiny paint gun brush and it lo

Posting with my phone ...was not a good idea.

Anyway, I cleaned the Map sensor and its plug. Seems fine now. 

Using the DRB in a test program ...I note that it says the Injection pump is at 0 rpm. While the crank sensor and cam sensor say 780 rpm...engine was indeed idling at the time at about 780 rpm.

Coolant temp is -64 C...nope its not.

Engine load should not have been 100 percent either. 

Still thinking I have a wire or connection issue between ECM and VP44.

 Regards Chris

 

Makes sense. ECM is commanding max fuel because the VP44 RPM is too low. So you've got a communication issues between the ECM and VP44.

My plan is to check each wire from connector on VP44 to its other end with my meter.

I made a post it note up for each wire and where it goes to in the ECM.

 I am thinking perhaps it could be the yellow / pink wire that is described as

DL INJ PUMP, wire # 13 to the ECM

 Chris  

By looking at your map connection I wouldn't be surprised if you have other bad connections. I'd keep checking them all before I would do anything else 

Edited March 4, 20187 yr by JAG1

I checked all the wires from the VP44 to the  ECM they all have good continuity. 

So I start it and no more MAP code but no communication  from ECM to module on VP44. 

Using the DRB3 I get some weird numbers. With the engine idling it days the pump is at 0 rpm and fuel temp in the pump is - 17 C. It's much warmer here at about 15c today. Also says injection pump battery volts are at 11.99 while the rest of the connection are at 13.99 or so.

On 3/2/2018 at 8:23 PM, Marcus2000monster said:

I think he means a ECM for a Automatic tranny. 

Correct

I would have to say its most likely a VP44. The only data that is screwy is the data from the VP44. All other data you have posted from the ECM has shown to be in good working order but the VP44 communication error and the wild data from the VP44 is strange. 

 

You tested from end to end with 0 ohms.

 

The VP44 volts could be a bad fuel pump relay. You can swap the horn relay with the fuel pump relay and see if that fixes anything. 

 

The VP44, ECM and PCM all get there ground from the passenger side battery terminal. You might talk to @W-T about his ground wire post.

I have had 2 different VP44s and 2 ECMs on this. I have trouble thinking the same very unusual problem would be in the VP44.

I could be doing the testing wrong. 

My map sensor code comes back...low voltage or high voltage...2 codes come and go.

I parked the truck for a day or 2 until I get a friend here that is a bit better with electrical than me.

 Regards Chris 

21 hours ago, Dieselfuture said:

By looking at your map connection I wouldn't be surprised if you have other bad connections. I'd keep checking them all before I would do anything else 

This my thought too, when looking at the map connection its a signal that perhaps the rest of the electrical system needs a  lot of attention. Electrical can be really weird, just my theory, but one part of the electrical system can affect other areas seemingly unrelated. The entire system works as a whole so anything done to improve the overall will not be a waste of time.

Edited March 4, 20187 yr by JAG1