Starting issues

I have had this issue for awhile now. The car won't start unless I press the gas pedal. If I shut the car off after starting then it will start right up without pressing the gas. But if it sits for a hour or two and then I try starting it I have to press the gas. Sometimes I have to throttle it a bit to keep it going after starting the car to keep it from dying.

What I have done:

New fuel pump
Fuel injectors were leaking so I replaced all 6 with new
New fuel filter

Could this be air related. Took it to my uncle who is a mechanic he said it seems like it is idling low.

Thanks in advance for your help

So after doing some research on here it looks like this could be the iac egr or maf. Where is the iac located on this motor please help me I'm trying to get this car sent to Hawaii on Monday and would like this issue fixed. Thanks

I was going to suggest IAC. Do you have a tool that can scan? Is the idle steady during regular driving? (you mentioned it seems low) You should be able to watch the IAC position from a good live data scanner/logger.

First thought is iac. It's one of the three sensors on the throttle body, it has a plunger looking doodad, kinda phallic shaped, that is spring loaded. I'd replace that first, then try a MAF sensor. I've gone through three MAFs in just as many years.

When mine did this it turned out to be the regulator.

96riv wrote:

When mine did this it turned out to be the regulator.

Regulator? The one on the transmission? Vacuum leak? '97 and newer don't have a regulator.

deekster_caddy wrote:

96riv wrote:

When mine did this it turned out to be the regulator.

Regulator? The one on the transmission? Vacuum leak? '97 and newer don't have a regulator.

Fuel pressure.

IAC sounds like a fantastic place to start. The IAC motor has a plunger on it that opens during cold starts and idle to allow air behind the throttle blade when the blade is closed (otherwise the car will start or idle quite low once warmed up). Sometimes the IAC breaks internally, and the plunger stays closed. Electrically it's ok according to the PCM, so no codes or SES light will show up.

If you know someone with a GOOD scanner (not a code reader), you can remove the IAC from the TB and command it opened and closed in steps, and physically see the plunger moving. Usually when these things fail, you can pull the plunger/spring out of the motor very easily....

The IAC is the biggest "sensor" on the TB. It's round and about 1-1/2" long, like a small RC car motor. It has a 4 wire plug (LT GRN/WHT, GRN/BLK, BLU/BLK, BLU/WHT wires), and I believe it's held in with 2 screws...just so you can find it easy  


Easy test for the Fuel Pressure Regulator....pull off the vacuum line that goes to it. If Fuel comes out, it's bad.

Thanks. Where is the fuel pressure regulator located?

nebstewart07 wrote:

Thanks. Where is the fuel pressure regulator located?

Remove the large plastic engine cover if it still has it, and the fuel injector rails are right there on both sides of the supercharger. The regulator is the shiny round disc attached to the fuel rail with a vacuum line on one side of it.

96riv wrote:

Fuel pressure.

of course. Whoops!

nebstewart07 wrote:

Thanks. Where is the fuel pressure regulator located?

It's the round thing sticking off of the front fuel rail, passenger side. It has a single vacuum line going to it.

I got all the parts and my dad is going to change them tommorow since I am in Hawaii and the car is in Nebraska. He is going to replace one at a time starting with the iac. And see what happens from there. I told him to keep track of what it is idling at each time he changes the part. And see if each part fixes anything. Thanks for the help guys hopefully will have some results tommorow.

Hope this worked out.

Hey Guys, haven't been here for awhile. Still have the the Riv, lookin a little more worse for wear. She has had her issues but I cant bring myself to let her go. The last couple of weeks I ve had a issue during the first start of the day. There are no codes. The car starts, but runs really rough likes its not getting enough fuel. The rpm gauge idles between 500 and 800 but the whole car shakes. I have to really rev the car passed 3K and then she smooth ens out. I have changed the IAC, and the Fuel Pressue Regulator and now the Coolant Temperature Sensor, with no avail. I hooked up a fuel pressure gauge to the line. When I turn the key over it builds up pressure to and maintains 40 psi, after running for awhile and shutting the car off. The last guess I would make is MAF? Any ideas or help would be appreciated. I should also say that every start after the first is perfect and she runs and idles smooth the rest of the the time. This issue is just at the first start up of the day.

The way it builds pressure is not even close to normal? When you turn the key to run but dont start, it should jump up instantly to 40-45 psi. Watch this video, its should be the same results on the riv:



Have you ever change the fuel filter?

Thanks for the response Dave. From the research I had done on-line. I thought that if the fuel pressure gauge holds pressure after shutting off the car, then the check valve on the fuel pump was good, meaning that the rail holds fuel pressure. Also my car builds pressure as quick as the video you posted above at all other starts, just not the first start. It seems that the the rail doesn't hold pressure overnight or after several hours, but in more frequent intervals it does. Does that mean the pump is on its way out?

P.S. Yes I also changed the fuel filter.

Try cycling the key a couple of times before you try to start it in the morning. Key on, wait 2 seconds, key off, repeat. Then try to start the car.

The FP should build immediate pressure as soon as you key on, even on the first try, and the rail should hold pressure overnight, yes. It's possible that you might have an injector leaking down into the engine. This would flood that particular cylinder overnight, and would result in misfiring when you finally do get it started.

Abaddon wrote:

It's possible that you might have an injector leaking down into the engine. This would flood that particular cylinder overnight, and would result in misfiring when you finally do get it started.

This is a very likely scenario.

Thanks for the responses guys. I've tried cycling the key on - off three times in the morning, but the result is the same. How do I determine if its an injector leaking or a failing pump?

BMD wrote:

Thanks for the responses guys. I've tried cycling the key on - off three times in the morning, but the result is the same. How do I determine if its an injector leaking or a failing pump?

You'd have to have an Injector Balance Test done. It can be done very, very easily with the proper diagnostic equipment. Nothing on the car even has to come apart. We use the scan tool to "spray" each injector 1 at a time, and record the pressure drop. Whichever injector sprays the most fuel (biggest pressure drop), that's the one that's leaking.

It can be done with a Tech II and an FP gauge.

Ok thanks for that Scott. Just a couple more questions. Wouldn't a leaking injector cause the engine bay to smell like gas fumes? Also would swapping out the o-rings do anything, or are you saying this problem is with the internals of the injector itself?

P.S. What should a Injector Balance Test cost generally?

I guess I should say that before this issue began, I changed the Fuel Filler Neck. There was a lot of rust and crud in the hose lines after getting the old unit out, and although I believe I did a thorough job of keeping things clean some of the crap may have made it into the tank, but the screen on the pump and fuel filter should have gotten most of that right?

BMD wrote:

Ok thanks for that Scott. Just a couple more questions. Wouldn't a leaking injector cause the engine bay to smell like gas fumes? Also would swapping out the o-rings do anything, or are you saying this problem is with the internals of the injector itself?

P.S. What should a  Injector Balance Test cost generally?

No. The injector won't be leaking from the O-rings externally. What I meant was that the injector itself isn't necessarily closing all the way, causing fuel to drip into the cylinder. It's all internal and you'd never smell it. That's how the misfire happens. The top of the cylinder gets soaked with fuel, and it takes a bit to burn off the excess.

A balance test shouldn't be any more than an hour diagnosis. If the facility has an actual injector tester like we do, they'll go as far as unplugging all of the injectors (on the car), and hooking all of them up to an external computer/power source, and use the fuel that's in the rail to do a more extensive test. It's quite a bit more accurate, but a little more invasive.

Either way, if you have a good technician, he/she should be able to find the problem in an hour or less.

As far as junk in the tank.....it would be the other way around. The car would start up just fine as the sediment would more than likely fall off the filter or pickup screens overnight. It wouldn't be until the gunk made it back to the screen with suction that the car would start running like poo or even quit. You'd also notice a significant pressure drop.

Thanks Scott, I think that may well be the cause. I saw on line a guy who with a long screwdriver who was able to hear the ticking of the spring inside the injector and assessed which ones sounded like they weren't opening and closing as consistently as the best sounding one. I also saw some videos of guys removing all the injectors and spraying carb cleaner through them, would that help my situation or do you think that replacing the "bad" injector is the only solution?

Dave wrote:

The way it builds pressure is not even close to normal? When you turn the key to run but dont start, it should jump up instantly to 40-45 psi. Watch this video, its should be the same results on the riv:

Out of curiosity I checked the fuel pressure on my Dads 99 Park Ave. with the same motor as mine. On the first start of the day his car also slowly builds up pressure and didn't just ping right to 40psi when he starts the car. So whats normal on our cars a slow build up of fuel pressure or immediate?