DS4 IP experts

[Twisted Steel Performance]

I have a new build on the run stand and I'm having a lot of trouble getting the timing set. Everything I'm using was used a month ago so I know that part works, and I use GMTD on my laptop and have done it before.

Now, this time I'm using the customers used IP & injectors, and pmd extension harness, my known good pmd. It's very hard to start, very smokey burn yo eyes fuel, doesn't want to idle, skips and smokes worse if reved up...

Once hot, click time set, it won't idle if I try and get lower than 7*, target is 3.5* ......... get it to 4.5* and click offset learn it dies instantly, doesn't want to restart...

No matter how much I move the IP, I can't get the offset to change from -2.02 .... and it always throws the offset error code....

I'm so new to the ds4 y'all lead me where to go from here, I suspect IP or maybe a sensor but not sure how to diagnose .....

 

[ak diesel driver]

Those OBD1 systems can be a bugger to get out of that -2.02 mode. If you set the IP so the top of it is level it should be in the ball park. Then start it and immediately try to do time set. No waiting at all. Might have to do the resistor mod to fool the ECM that it's up to temp.

 

[Glagulator]

Possibly an HD IP problem?

 

[SnowDrift]

Can you rule out all other possibilities by test running with your known good DB2?

 

[ak diesel driver]

It's usually the PCM that get's stuck in that mode. If you had a different PCM you could get the IP adjusted and maybe that would kick the PCM loose

 

[dbrannon79]

I have always had good luck when I set the base timing to 3*. it could be a finicky PCM too. being a new build with tight tolerances there is really finite movements of the IP to get it there.

if you have another truck or setup where you don't have to swap IP's out and just plug in that PCM and attempt to do the time set procedure, that would get the PCM out of that loop. would also rule out if the PCM is the issue.

when I was leaning and did this for the first time on my 95 and me not knowing any better, I actually did the first time set loosening the IP nuts and snugging the top one, adjusted the base timing with the engine running watching the laptop. a last ditch effort that might help.

before the build, I assume this IP was on your customers engine and running fine. if it had an engine failure that may have caused damage to the IP or maybe damage during shipment. IDK how fragile DS4's are if a package was dropped and kicked around during shipping.