Hi,
I changed my multecs for bosch III.
Now I don't get the high idle at startup like I used to get.

New O2 sensor.

Install was careful - no leaks - no vacuum leaks(checked with spray around gaskets/lines and injectors.

disconnected CPU to reset learn.

FPres = 48 check with gauge while running.
No leaking injectors now either.

Runs great once warmed up, but cold start is a problem now - low idle almost dies - needs throttle until warm to run.

Maybe I need to let it learn for a tank or so.

Here are my current scan results:

No codes
Prom 3531
coolant temp 186.8
TPS 0.56
rpm 689
O2 57mv
O2 cross count 70
Block learn 142
Rich/Lean - lean sometimes rich
FP volts 13.6
Integrator 128
O2 sensor ready
Injector pulse 1.4ms
Load 35
Mass Air 5gr/s
batt 13.7
Spark adv 15.7
Knock retard 0
Maifold air temp 104
Learn Enabled
Loop - closed
IAC 0 steps pos 12 - looks out far - checked for vac leaks - found none.

I plugged egr line for this run.
I checked the CTS when hot - it was 442 ohms
still need to check cold.

Please suggest next steps.

Regards,
-Brent

 

I Failed to mention:

I raised the FPress to 47 or 48 trying to solve this - did not help
Double checke minimum air
change IAC and reset with part throttle for 5sec start/off10 sec then start no throttle.
It was 45.

I also checked the resistance of the new injectors before installing since my old ones had a couple down at 7-8Ohms.

All new ones were almost exactly the same at 16 Ohms cold.
Have not checked hot, but did check with stethoscope to make sure each one is working.
They are noisier than the multecs - but probably fine.

 

Subscribing... same car, same issues. Mine has cold high idle, but bogs pretty bad when you press on the gas pedal of idle. Must be very easy with it. It will backfire through intake a little also. When it does catch its like somebody hit the secret nitros button. These symptoms are only when cold though. I cannot find a vac leak anywhere. FP is around 42 when primed and ~35 when idling. This happened after the Bosch III's.

 

What is your vacuum at startup?

 

I will have to check. Does the CTS get checked at startup to run in open loop?
Changing injectors seemed to have messed up the initial startup - then after warmup -closed loop and runs very good. Sort of the opposite of the behavior the day prior to swapping them.

 

What size engine?

What lb. rating were the injectors that came out?

What lb. rating were the injectors that went in?

 

Check your TPS. I had a car a few years ago that did not want to idle after a cold start. It would almost die and had to be given gas. I know your scan results are good, but I find more often than not that the sensors aren't really bad, but the wiring IS. Look for intermittent wiring problems. Bad grounds especially.

 

22lb orange bosch III - 22lb multec came out - 350 tpi.
I will double check the gnd's - nothing was touched there in that 24hr period, just fuel rail and plenum.
I sprayed carb cleaner around the gaskets and injectors while running and I could not detect a vacuum leak.

A few months ago, I re-seated all grounds I could find.
Where is the main one for the ECU located, I'll check that one.

 

I checked my TPS and set it to .56v - was .52v at idle
I also ohmed it since it just a variable resisitor and slowly moved through the range - looks good, no dead spots in the resistor wind/contact swipe pickup.

 

Bad grounds don't cause the BLM's to hit 140 guys. Jeez. It's running lean after injector install, but has low idle (so no vacuum leak). It's still lean once warm, but not as noticeable because the engine requires less fuel. Also probably longer crank times because this is not a 9 injector car.

First thing to check is correct injectors were used and it sounds as if they were. So where does that leave us?

Pull the plugs. Check for any that are noticeably lighter. My guess would be that one or more of the injectors is DOA, or you were sold the wrong size.

 

I ohmed the injectors before installing - all at 15.9-16.1.

I used the stethoscope type device to listen to each one and they all are clicking.
Maybe a bit more Fuel pressure?

 

Increasing FP made the cold starting issue worse - backed it back off to 47 again now - maybe try lower.

 

Should be around 43 I think, possible you have to mess around some to make up for imperfect flow rates. Don't hold that one against me, just a guess

 

More progress - while idling, I pulled on the wires coming from the TPS connector and I could get the idle to change by doing just that. I can't find anything broken with the connector or opens in the wires, I believe it is the connector itself, the pins inside do not make solid contact with the connector inside the tps.

How do you pull the pins/wires from the connector?

I zip tied the wires in the directions that improves the idle and this may solve it temporarily.

Once again, I used a whole can of car cleaner trying to find vacuum leaks and there are none.

TPS voltage is looking good when I scan it, but it did before too, so I guess removing the connector to do the injector swap, triggered the issue.
TPS shows very smooth(no jumps) when I ohm it and move it slowly through the range, so the TPS is good.

 

http://www.etoolcart.com/terminal-tool-lis14900.aspx

use this tool !!!

 

Good idea - looks like a handy tool to have - thank you.

The issue is solved now - I just now need to disassemble the connector and bow those pins inside the male portion out a little to make sure they make good contact when connected. Right now the wires are pulled to the side with a zip tie to help finish my experiment.

The TPS internal connectors are solid. The connector pins have taken a set to not make strong contact within the TPS itself. Tough one to find since I figured, I must have put a gasket on backwards, or even the runners on backwards - even though I was very careful - it's always a doubt.

I suspect this is the root cause of many issues here.

The male portion of the connectors take a set and stop making a spring-out tight connection to the tps connectors which are little tubes themselves. Pulling the wires to the side after the connector was installed forced the connectors to make clean contact inside the tps connections. I have heard of similar issues with a MAF.

I had to wait overnight for a cold start to say for sure, but it's all fine now.
cold start - fires up promptly, idles at about 1500, then drops as it warms to about 700, then when in gear idles at 650. That' good for me. Idle and throttle response is very good now.

Now, I'm glad I changed the injectors!

Regards,
-Brent

 

Quick question.. Are you changing the female pins out with new ones or just removing them, bending them so they make a tighter fit and then re-installing the used pins.

 

My plan is to remove the pins from the connector side and bend or bow them slightly so that they will make better contact inside the TPS accepting pins(which are little tubes). The pins on the connector appear to have a closed umbrella look to them. I think any change to make them larger diameter is the idea. I should just get a new connector - maybe I can buy just the pins and splice new ones into the old connector.

 

http://www.ebay.com/itm/Weatherpack-...ht_2968wt_1032