Hanging Idle with FRPP/Deka 80s

[Power Surge]

Hanging idle seems to be a common issue when running FRPP/Deka 80 lb injectors, especially on older EEC5 PCMs. Anyone have suggestions on how to resolve that? Thanks in advance.

[Power Surge]

bump

[decipha]

thats odd indeed, Ive literally tuned several hundred vehicles with siemens deka 80s as well as 10 of my own personal vehicles GM and ford alike and Ive never once experienced nor even heard of that.

A hanging idle isnt exactly a technical term so I can only assume you mean its not returning to idle not only while stopped (idle) but during decel too (dashpot)? Thats extremely easy to solve. As far as being tune related there is only 3 possibilities for eec-v.

1) throttle state is not returning to closed so dashpot stays active as well as pt spark- verify throttle position goes to -1 == closed throttle. Very common issue is usually caused by a bad tps sensor or jitter causing ratch to jump up. If it is the culprit you can kick up the DELTA (pt threshold) scalar to fix it short of mechanically of course.

2) dashpot gets clipped, verify by logging dashpot to make sure its decaying during the condition, if not you figure out if your hitting the dashpot min clip function or if your dashpot decay rate needs to be kicked up

3) idle air or throttle stop not properly adjusted. You can verify by logging the 4 ISCKAM (long term idle air corrections) and IPSIBR (short term idle air correction) and make sure both are near 0.00 at a warm stable idle and the isc multiplier table is dialed in correctly for startup and cold starts. ISCKAM and IPSIBR should never make more than +/- 0.05 correction.

full details

http://www.efidynotuning.com/idleair.htm

http://www.efidynotuning.com/dashpot.htm

[veeefour]

Oh boy oh boy here we go again - 80's are shitty and you can't tune them boooooo...

Good injectors for the money.

[Power Surge]

thats odd indeed, Ive literally tuned several hundred vehicles with siemens deka 80s as well as 10 of my own personal vehicles GM and ford alike and Ive never once experienced nor even heard of that.

A hanging idle isnt exactly a technical term so I can only assume you mean its not returning to idle not only while stopped (idle) but during decel too (dashpot)? Thats extremely easy to solve. As far as being tune related there is only 3 possibilities for eec-v.

1) throttle state is not returning to closed so dashpot stays active as well as pt spark- verify throttle position goes to -1 == closed throttle. Very common issue is usually caused by a bad tps sensor or jitter causing ratch to jump up. If it is the culprit you can kick up the DELTA (pt threshold) scalar to fix it short of mechanically of course.

2) dashpot gets clipped, verify by logging dashpot to make sure its decaying during the condition, if not you figure out if your hitting the dashpot min clip function or if your dashpot decay rate needs to be kicked up

3) idle air or throttle stop not properly adjusted. You can verify by logging the 4 ISCKAM (long term idle air corrections) and IPSIBR (short term idle air correction) and make sure both are near 0.00 at a warm stable idle and the isc multiplier table is dialed in correctly for startup and cold starts. ISCKAM and IPSIBR should never make more than +/- 0.05 correction.

full details

http://www.efidynotuning.com/idleair.htm

http://www.efidynotuning.com/dashpot.htm

Thanks for your reply

I don't believe it's a dashpot issue, as there wasn't a dashpot issue before changing injector size (on multiple vehicles).

I'm almost certain, that the issue is I've got poor values for these 80s. There seems to be quite the debate on what the proper values are when using these specific injectors.

Since you've had such great luck tuning with them, would you mind sharing your values for using these? You can PM if you don't want to publicly share them.

Thanks for your help

[veeefour]

This is the correct data for 80's and it works fine:

https://performanceparts.ford.com/pa...-9593-lu80.pdf

[Power Surge]

This is the correct data for 80's and it works fine:

https://performanceparts.ford.com/pa...-9593-lu80.pdf

Thanks Veee.....I'll compare that to what I have been using

[Power Surge]

Hmmm....those are all the same exact values, with the exception of minimum pulsewidth. The chart shows 0.599, but the value in my software shows 0.000599.

[veeefour]

Check the unit - either s or ms

You can lower a min PW if you have rich condition at idle - those are 80lbs injectors with a single hole so don't expect them to be super smooth at idle.

[decipha]

keep in mind 80s exceed the injector clip limit on eec-v so you have to scale it. The deltap multipliers are factored in to the clip as well so stay below it.

details

http://www.efidynotuning.com/fuel.htm

I use my own software to realtime tune eec-v so unless you can import a bin file I wouldnt be able to send you anything