ChR1sCRX

Hello Folks, I'm hoping someone here is familiar with troubleshoot the two port throttle body injection on the DX. I have the manuals for the CRX but they don't address the 2 port setup. My problem is this, I have a code 16 with is an injector issue. Fuel pressure seems low. At the test port on directly out of the tank it is only about 15PSI. If I give the pump 12V directly using a jump box - Pressure rises to about 45-50 and the car seems to run better. I need to know what the pressure for the DX dual port is supposed to be. Also, the pump does run with the stock harnass but it doesn't seem to be running right... bad ground? I did check the thermostat ground and it seemed quite clean where it contacts...

Help? I'm think bad wiring to the fuel pump but I'm not sure that would give me a code 16?

Thanks!!!

ChR1sCRX

Hello Again,

OK - So here I am with a walbro pump installed, pressure is good but as soon as I give the car gas it misfires all 4 cylinders. If I keep the throttle to the floor it will stall out completely. If I give the car very light throttle it will rev mostly OK but not cleanly. I'm think injector problem? Code 16 is an injector issue so any help would be appreciated. Thanks!

Bump!

BiG_DeE

Check your Dizzy.. sounds like it could be Ignition Control module, i was having same issue, replaced the fuel filter still was cutting in and out, i could run my car until i was to rev it. then it would die.

also check your spark, if its weak then you know its something to do with distributor.

ih8sndq

You may have too high of a fuel pressure now if you did the 255lph walbro. That happened to me when I installed a 255 walbro. I had to do the trick where you drill through the regulator to lower the pressure. There is a site, sorry I can't remember, that shows you how to do it. But only do it if you determine that your pressure is too high.

Laserjock

Buy a decent Radio voltmeter usually under $30 and measure the resistance across the 2 pins on the injector.

There is also a checkout for the resistor box. Do a search

Injectors are classified into two categories.
1. High impedance/resistance (saturated) 12-16 Ohms.
2. Low impedance/resistance (peak & hold) 0.5-6 Ohms.

Saturated injectors require roughly 1-1.5 amps to open the injector. Peak & hold injectors initially needs about 4-6 amps, and once open drops to roughly 2-3 amps to keep it open.

ECU design will dictate the use of one or the other. Most late model cars will use saturated injectors.

http://www.rceng.com/faq.aspx?UserID...my_application

ChR1sCRX

Ok - So update - checking the resistance on the main and aux injectors revealed the aux is fine and the main is shot. Should be between .6 to 1 Ohm. I got .8 on the aux and .1 and the main. So its definitely the main jet - good to know about too high pressure. I'm not quite sure what the DX is supposed to show... I believe the correct way to test is with the FPR disconnected but the info is inconsistent for the DX.

ChR1sCRX

Update to my update - The car runs fine now. It has been for a couple of weeks, I wanted to share what I found in the case that someone else runs into this problem or rather any of 'these' problems.

#1 - There was nothing wrong with my main injector - I had the wrong values. The main read 1 Ohm and the Aux read .8 - this is within spec. I thought they were supposed to be the same however they have different resistances. I'm pulling this from memory so double check me if you are using this info to trouble shoot your own.

I actually had more than 1 problem - the largest of them being the idiot(s) who worked on it before me.

#2 - There was no gasket sealing the TB to the intake. Huge vacuum leak - no wonder it would not accept throttle. Amazing that it idled!

#3 - This is probably the most useful piece of info in this thread for folks with a DX that has an idle problem and/or a throttle problem. The DASHPOT. There are two devices on the DPFI Throttle Body that look like dashpots. The culprit for most folks problems is the one on the left of the TB that connects to the throttle via a small linkage. It has a single vacuum line that activates it. It's purpose is to damp the throttle movement likely for emissions and cold starts... I'm assuming this is the case based on what it seems to do - so anyone with more info please feel free to add or correct me). When this thing goes bad it becomes a double wammy. Since it is directly connected to the throttle it can affect throttle action and throttle idle position and since it is vacuum activated, when the diaphragm craps out it becomes a vacuum leak - a rather large one in most cases.

It is very easy to test to see if this is your problem. Simply remove the vacuum line and plug it. If the car runs fine after that - then the dashpot is your problem. You can actually remove it all together as many have done, however I just replaced mine with a good junk yard unit. It's very easy to tell well you have a good unit since vacuum will operator the leaver coming out of the dashpot. You can even operator it using your mouth as the vacuum source and check to feel if the lever moves.

Apparently, this dashpot thing is a very common problem.

#4 Once I had that all fixed, I had a pretty severe idle hunt (Idle Surge) - I just took apart and cleaned the IACV and now my cheesy DPFI motor purrrrrs like a 200,000 mile kitten. Actually - what scares me is that it's so quiet. I bet the valves are tight. Does anyone know if the B15B2 tends to wear valves tight or loose over time??

Here's a few pictures (Top IACV - Bottom is the DPFI TB and the yellow striped hose goes to the dashpot I speak of).

singlecamsaint

take that choke out man it will run tons better.