Starting problems

s_wilwerding · s_wilwerding's Garage

For about the last month and a half, I have been having intermittent starting problems. Sometimes, when the car is cold, I can crank the car but it won't turn over. It's not a problem with the starter - it cranks fine.

I've found that the only solution to the problem is to take off the air filter and manually push the float up a few times. After that, the car will generally start roughly, but after a few seconds will run just fine. Once the car is running, it will continue running and idling just fine. Lately, I've also been having trouble starting the car when it's warm. If I drive the car for an hour, leave it sit for 10 minutes, and try to start it, I have the same problem.

Any ideas? I don't think it's a fuel or ignition problem, since the car runs fine once it's started. Also, it's an intermittent problem - most of the time, the car starts fine cold, but sometimes I have problems. I'm thinking something in the CIS is bad (or going bad).

Thanks.

jstobo · 03-31-2003, 06:47 AM

Steve,
Cold start problems can be the cold start valve or Auxilary air valve. Warm start the fuel accumaulator (suppose to hold pressure). The WUR (warm up regulater) is the control pressure regualtor and it could be also be bad. And if the fuel pump is bad and all pressures are off then that could be it. You need to pressure check the CIS. Take it to a good mechanic with the proper gauges. If you rather DIY get a good CIS book and buy what you need . I have seen the pressure gauge with lines for less than $150. You could probably rig one for less but I am not sure the time it takes is worth it. Good luck.

Superman · 03-31-2003, 07:26 AM

Steve, your CIS system is leaking residual fuel pressure, a common thing. No doubt about it, particularly with your hot restart problem after sitting 10 minutes. Classic.

The possible culprits include fuel pump check valve, fuel accumulator, injectors. An inexpensive check valve can be added to the end of the fuel pump, rather than replacing the pump. This is a common pressure leak source.

s_wilwerding · s_wilwerding's Garage

How difficult is it to install a new check valve? Do you think I should just order one and try it out? (They're only $18).

EDIT: One more question - how does moving the float help the fuel pressure?

s_wilwerding · s_wilwerding's Garage

Anyone? Super?

Superman · 03-31-2003, 03:19 PM

Steve, I think you are talking about the air flow sensor plate, and I don't know how moving it would help anything, unless it's just a matter of loosening it up. Sometimes, CIS systems can act funny because the rest position of the sensor plate is not exactly correct. But don't get ahead of yourself. That comes later in the troubleshooting process.

With your warm start problem, there is virtually no question that your residual fuel pressure is leaking down. Installing the extra check valve is pretty easy I'm sure, but I thought I heard that there is an elbow piece that needs to go in at the same time. For reasons of physical room, I'd guess. Perhaps a search on the check valve install process would help you.

Once that is done, then see if the problem persists. If so, then we find something else as a cause. A CIS pressure tester is a necessary thing, for troubleshooting CIS systems. I saw one in JC Whitney, and Pelican probably sells them as well. Hot start problems like you describe are related to residual fuel pressure, but this problem usually does not affect cold starts. Still, I'm recommending that the residual fuel pressure problem be fixed before we accuse your engine of other misbehaviors.