Now you've done it Ollie! Newbie 1G requesting help diagnosing swap/turbo issues

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E-Man

No idea what I'm saying
Reaching out to all FI/swap gurus as I've acquired a 1G Crx turbo project. I'm trying to diagnose the source(s) of three issues, (1) an erratic idle that surges primarily when cold but also intermittantly under normal operating temperatures; (2) an intermittant bog/hesitation upon casual acceleration when the engine is cold and (3) PGM-FI light comes on intermittently.

what we have:

1985 CRX si
B16A OBD0 swap, ZDyne Gold SECU (without a copy of the uploaded tune)
T3/T4 turbo, DSM 450cc injectors, adjustable fpr, manual boost controller.
(let me know if you need more input)


Car smells like its running rich but it could be partially if not all attributable to not having a cat.

I recognize that this may be above my capabilities but nonetheless would like to try to fix some of the above prior to seeking professional assistance.

Your input is very much appreciated!!!!!

Thanks in advance for sharing your wisdom.

E
 
if you're getting the PGMFI light, then there should be a code stored in the ECU

OBD0 codes can be found here: https://hondaswap.com/reference-materials/88-ecu-error-codes-29109/


the idle surge could be the fast idle sensor loosening up from vibration....
take the plate off there is going to be a white plastic diaphragm inside with notches on the sides take a screw driver turn it in (clockwise) until its tight
 
you're on LI with a little CRX? good luck. the potholes in the city are bigger than your car.
 
Yes. It is Bryan's former car.

And no the potholes aren't too bad as long as you avoid certain roads...
 
E-Man said:
Yes. It is Bryan's former car.

And no the potholes aren't too bad as long as you avoid certain roads...
Click to expand...


thats what i thought. i remember riding in it. goes like stink, but i guess you knew that already. anyway, have you contacted him or the guy that built it about the problems?

if the FI light also comes on when the engine is cold the codes should put you on the right road to correct the problems. you say it smells rich and bogs under casual acceleration; im no expert, but that says to me that the closed loop fuel map needs work. figure out what codes the ecu is flashing and put it on a wideband DL.

how does it do under wot?


scott
 
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No issues so far on WOT. Spoke with both Bryan and John and the issue may lie in the tune on Zdyne as most are unfamiliar. As you may be aware, Zdyne does not provide datalogging which doesn't help my situation. Not having a hard copy of the tune is not helping the situation......

I hope to have some time on Saturday to start some basic diagnostics. I'll have to pull the Sparco to gain access to ECU codes and will check out Eric's advice on the idle sensor as well prior to checking for vacuum leaks. After that I'll have to get a wide band.
 
excuse my ignorance, but what is stopping you from using a stock ecu that has been chipped, and modded to accomodate dl?


scott
 
Once I determine that the cause of these ailments are not "mechanical", I'll have to consider my options including having a stock ECU chipped/socketed or conversion to OBD1.

This FI stuff is new to me (makes the B16 swap I did for my son seem simple) but time is on my side as winter is approaching. If I can't figure it out I'll focus my attentions on the bodywork that needs repair.

Red Pepper is a great site but does not have much emphasis on FI

E
 
Eric,

Here's the current update. Only code is 1-17, VSS/circuit. Haven't had a chance to look at the fast idle adjustment as I was more focused on dismantling the old hood and header panel to prep for the 1 piece hood. Next up is sandblasting the used hinges I acquired, alignment and paint prep.

Next window to work on Rex is most likely post turkey day.

Thanks again for your help.

E
 
I wonder if the 450's are too much for the system...hence the bogging/surge?

you said it was running low boost right?


Speaking of the VSS code, I wonder if the speed check is disabled (if its not Vtec won't kick in)
I don't if the code necessarily means "I'm looking for the VSS so I can trigger the Vtec solenoid"...but that might be an issue worth looking into

Does it do it at a certain RPM?
 
All,

Finally got a chance to work on the Rex today and look into the surging idle issue. After much research, I agreed with Eric and would start with the fitv.

It sure was challenging clearing the way to access the fitv. Found a write-up on Honda-Tech but encountered some differences as to how the fitv was mounted- Now I'm wondering which IM is attached to the B16A as it doesn't appear to be the original.

I decided to remove the fitv as it would give me the opportunity to take a closer look at it ad clean if necessary. It appeared secure much to my dismay and I disassembled and cleaned with some Gumout. Unfortunately, I couldn't access and pics of others to compare against my reassembly and decided to wing it and reinstall.

Looks like it did the trick. Surging idle remained for a bit but eventually went away as the air was bled out of the system. Hopefully its gone for good.

Kudos to Hosmer and the rest for all the advice. Next up is to see if the bogging remains.....

E
 
The FIT Valve works with coolant and coolant temp. Inside of it is a plunger. Remove the brass bottom plate (two screws) after you remove the FITV housing as well as the two coolant lines. Plug off the return line for coolant will flow all over the place if you don't. Make sure the plunger isnt rattling around inside the FITV housing. Re-assemble if ok, and make sure you have coolant in your system.

An easy way to diagnose most idle issues would be the throttle body test. Take your intake off and look inside the TB. There will be two holes, one for the FITV, and one for the IACV. The top hole is usually for the IACV. While the engine is running and the engine is at normal operating temp., put your finger over (to close) the top hole. If the idle corrects itself (you will feel vacuum on your finger), than your IACV is at fault. If you do the same to the bottom hole and the idle corrects itself than your FITV is the problem. If those fail, check for a bad intake manifold gasket, loose manifold/tb bolts, or vacuum leaks on the manifold.
 
Unfortunately the rebuild of the fit valve was short lived as the surging idle returned after a test drive last week. Prior to the reassemble I visually inspected the O-Rings as well as the plastic housing and bullet. Obviously I missed something in my inspection. Vacuum is still this issue in the FIT Valve.

I decided to spend the $ and purchase a replacement from Acura. Will install this weekend.

The bog does not appear to be mechanical but tune related - I'll eventually have to come to a decision whether I'll change fuel management systems as I'm striking out big time finding a local tuner familiar with the Zdyne.

E
 
Changed to a new FIT Valve today. All is well again. For those searching for the part # for the FIT Valve for a 1st Generation B16A its 16500-PR4-A01.

Thanks all,

Elliot
 
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