checkmate1996

CIS Gurus,

Over the last few months, I've noticed it's getting harder and harder to start my car in the morning. For example, it took atleast 5 minutes this morning and about about 8-10 short cranks before it caught. Once it catches, the Aux Air kicks in and raises the idle for two minutes. After that, the car runs GREAT. Idles perfectly at 800-850 RPMs. I have no power issues or apparent power loss or dead spots. I have no issues with starting warm, even after having the car sit at work for 4 hours to grab lunch or leave at the end of the day. One crank, and off she goes. However, it's overnight which seems to be the cultprit. I thought it might be the battery, a dead cell or something even though I just replaced her 6 months ago. So after two days of sitting in the garage, I checked the battery with a VM. 12V exactly. Ok, that appears to be good. After reading several posts, I bought the bosch blue book and a set of gauges to get some accurate readings, but I'm hoping it doesn't lead to a new WUR but something easier to resolve.

Items recently replaced: Both fuel pumps and fuel filter.

Ok, so here's my order of troubleshooting:

- Thermo switch -
- Cold Start Valve
- Ignition Coil

Any other inital tidbits? Thoughts?

hupp

Doesn't sound like the WUR is your problem. If this was the case you would have power issues, and based on your diecription your shark seems to run fine during warm up as well.

The problem seems to be in getting fuel to the intake during the first start. OR you may have a leaking injector. You mentioned changing the fuel pumps and filter recently. Did your issues start after this?

I'll take a guess, but once you put your gages on the system you should have a good idea. My gut tells me that either your cold start valve is not working or your fuel accumulator is bad. Cold start issues could be with the valve itself or with the thermal sensor as you mentioned. Your accumulator could be leaking past the diaphram or at a fitting that you loosened during your filter change.

checkmate1996

Hupp,

Thanks for the response. No, I've had the filter and fuel pumps on for a 1.5 years. The symptoms have slowly worsened over the last 2 months. Its now starting to register at 'annoyance level' ...

Chuck Schreiber

Brad,

Mine has done what you're referring to ever since I put in new pumps, fuel accumulator, filter, etc. o It used to start on the first crack every time, even if it sat a month!!! I'm waiting on the thermo switch to come in to see if it cures this problem, along with my 15 minute cycle on loss of power.
BTW, what is your take on the power of your 5.0 Hybrid vs the old stock us motor?

checkmate1996

Chuck,

Keep us posted on the thermo switch. Also, can you discuss what you mean on the 15 minutes cycle of loss of power?

"BTW, what is your take on the power of your 5.0 Hybrid vs the old stock us motor? " ... taking a quote from Empire Strikes Back, "Impressive, Most Impressive!"

Low end and top end are noticeably different. I know I could run with any stock S4 maybe even GT given the weight of my car and HP/Torque it's producing. The only downside is highway driving, it sucks up gas...even in 5th gear I'm doing about ~2800 RPM at 75-80mph. The upside is that it doesn't take much to weave in and out of lanes! This engine is the brainchild of John V. He sold to me to build a stroker. With headers and straight pipes it's fast but raw. It's not something I would go out on a date with!!

checkmate1996

So nobody is thinking ignition coil?? I guess I would rule it out too since the engine runs great once started...am I right in thinking this?

glork98

I'm thinking no power to the cold start valve. Use a voltmeter to check for power to both CSV and Aux Air valve.

Chuck Schreiber

Brad,

I swapped the ignition coil, tzk, no effect. I replaced the ignition switch, green wire, clean/and or replaced all relays and fuses (took the whole fusepanel apart) no effect. Replaced fuel pump relay.
Still takes a while to crank. Usually starts up on the second time to crank.

My intermittant or 15 minute cycled power problem is still making me chase my tail. The care once heated up will loose power gradually after about 15 minutes of running to the point that it can barely move if the accelertor is applied. Turn the car off and then back on and it cures it. Another 15 minutes later, same thing. Next thing to try is the thermo-switch. Will pick it up tomorrow and try to replace over the weekend. It's taking me forever as I'm pretty limited on time these days with work, kids sports, etc. Everything I've replaced needed it so sooner or later I was going to have to do it anyway.

I'll let you know how it goes, You do the same.

jpitman2

I would look at the accumulator(under cover in front of RR wheel). Mine had a half warm start issue - cold starts ok, but 2-4 hrs asitting after hot, lots of cranking. replaced accumulator, problem gone. Some had a vent hose going to fume tank under RR fender, some just a blanking screw on top. When I opened the screw in mine it was wet, which indicates diaphragm is perforated. Your problem is a bit different ---try bridging the pump relay when cold for a few seconds, then try starting it - if the pressure is bleeding out overnight, it might take all those starter tries to get fuel up to the distributor. Either accumulator or pump check valve could do this.
jp 83 Euro S AT 50k

heinrich

clean it well.

SharkSkin

Even if you have power to the cold start valve, it could be plugged. It gets used very seldom compared to a regular injector.

checkmate1996

Can the cold start be cleaned?

Wouldn't I see other problems if vacuum wasn't there?

Ok, I'm stumped. What is the fuel accumulator? I have NOT replaced this assuming it's different than the two fuel pumps and the fuel filter...

Update:/Edit

Uggh! I just saw the cost of a new fuel accumulator and I have not replaced this. Can this be cleaned? What does thing do? I presume the fuel filter is right next to this thing...

jpitman2

The accumulator is under the cover in front of the right rear wheel usually. Its just a spring and rubber diaphragm to hold pressure in the system after the pump stops, to prevent vapour locks when heat soaks out of the stopped engine. Not repairable AFAIK. Check for wetness at vent or screw - if so, bad. Cold start injector should be cleanable same way a normal electric injector is cleaned, thats all it is. When yours is stumbling and running badly on first start, is there any sign of black smoke(=rich mixture) out the exhaust? I would usually expect to see(or smell) some unburnt gas there on first start. If not...sounds lean? Can you get a pressure gauge set on the WUR line?
jp 83 Euro S AT 50k

928BC

A good Quick check to see if your cold start valve is working is to unbolt it from the plenum, keep the line attached, and put a clear bag or two around it then crank the car when it's cold.

When you replaced your fuel pump did it have an integral check valve to the pump or is your check valve part of the banjo bolt?

Chuck Schreiber

I've got a relatively new (low mileage on it) cold start valve, new accumulator and check valve. My car started worse after I replaced the 2 pumps, check valve, accumulator, and filter. Go figure??