Occasional hard starting issue..

[boat]

Read carefully.

Trying to diagnose a hard starting issue, I have had it for more than a year. It is getting worse.

I tried diagnosing this back in April of last year. The fuel pump has been replaced with a walbro from SHO source.

I have no engine codes. A front 60k was done last February/March with NEW parts. The issue existed before the 60k work was done.

In order to overcome the issue when it happens, about 3-5 times a week, to get it started I have to put the gas pedal down 3/4, and then it will start and run just fine with no issues once running.

I read something in someone selling a gen 1 sho on craigslist, talking about having the same type of hard start issue "sometimes", having to do the same thing to start it. He narrowed it down to a secondary fuel pump circuit failure.

Anyone else had this issue? How did you fix it?

 

[Eric VerValin]

secondary is just the 'low speed' mode i believe... purge cylanoid maybe? clogged charcoal canister maybe?

 

[jayro]

Also, if it is talking about "low speed"....I believe that only the gen I's had a 2 stage fuel pump circuit. That is why the gen I's can run a larger fuel pump without having to get an aftermarket fpr. Have u changed your fuel filter? Is it when the car is hot or cold? When it does the hard start thing, does it stumble for just a second when you start it up? Mine will do this sometimes, but mostly when its hot. You may have answered these in the other thread, I didnt go back and read it.

 

[jayro]

Okay, so I read your original post (for the most part). Basically, the car wont start, but if you put your gas pedal to the floor it starts, chuggs for a second and then runs fine. If this is the case then I would say it is definatly something with the fuel delivery. But too much at start up, not too little. flooring the gas pedal at start up cuts off the injectors. Basically resolving a flooding issue. (You probably already knew all this). You changed your injectors, right? Did you know that the new ones were good? I know you can have them cleaned and checked to make sure they are functioning correctly. These type of continual issues can be a pain.

 

[rubydist]

does the hard start happen any time, or just when the engine is cold, warm, in between???

 

[boat]

It has no favorite time of being hot or cold. It just does it when ever it wants. Sometimes warm, sometimes cold. Fuel filter, it is/was doing it before and after replacing the fuel filter.

Also, if it is talking about "low speed"....I believe that only the gen I's had a 2 stage fuel pump circuit. That is why the gen I's can run a larger fuel pump without having to get an aftermarket fpr. Have u changed your fuel filter? Is it when the car is hot or cold? When it does the hard start thing, does it stumble for just a second when you start it up? Mine will do this sometimes, but mostly when its hot. You may have answered these in the other thread, I didnt go back and read it.

Doesn't really chug any more. It was doing that then when doing all the troubleshooting, unplugging maf, and IAC, measuring for voltages while the PCM was unplugged.

Okay, so I read your original post (for the most part). Basically, the car wont start, but if you put your gas pedal to the floor it starts, chuggs for a second and then runs fine. If this is the case then I would say it is definatly something with the fuel delivery. But too much at start up, not too little. flooring the gas pedal start up cuts off the injectors. Basically resolving a flooding issue. (You probably already knew all this). You changed your injectors, right? Did you know that the new ones were good? I know you can have them cleaned and checked to make sure they are functioning correctly. These type of continual issues can be a pain.

Pretty much anytime.

does the hard start happen any time, or just when the engine is cold, warm, in between???

 

[SHOtime2511]

cam sensor been replaced?

 

[boat]

I almost wonder if it would be the charcoal canister, like Eric Vervalin suggested?


Yep. I had the same issue before I replaced it about a year ago.

cam sensor been replaced?

 

[Eric VerValin]

Mine sometimes acts the way you describe... after the new starter and batteryI havent had an issue... yet.. but I have had that backfire out the intake once.. I replaced the canister.. but never did get that valve... I just wonder if a slow leak of fumes dosent work its way into the intake.. ?

 

[itwonder]

Try temporarily using a procedure of cycling the key to ON to let the FP prime, then key back to OFF. Repeat 3 times. Then start. If starting gets better, it tells you your FP is not holding pressure and is leaking down.

If it does not fire, but after releasing the key back to ON and going to Start again (might take two cycles) it does fire, then that points to a CID problem.

 

[rubydist]

generally, a cam sensor problem will result in no tach movement during cranking.

 

[boat]

I have a theory.

My oil cooler to block gasket is leaking oil all over my starter.

Here is what I am thinking. On the occasions where it is hard to start, I think oil gets in somewhere where it shouldn't be and makes it difficult to start right away. Then once I have tried starting it once and it does not, there is unburned fuel dumped in thus, not allowing it to pour any more fuel in to make an attempt to start, then I put the gas pedal down about 3/4 throttle to cutoff the fuel, it then starts off the fuel already that has already been dumped in as I turn the key again.

Is this possible? Am I thinking right? It seems like the only thing I can figure is causing this hard start issue.

Replacing that oil cooler to block gasket is next on my list. I guess I will know once I replace that gasket and clean up my starter if truly my thinking is right or not.

Discuss...

 

[Eric VerValin]

Your thinking too hard again... lol

 

[SeanMc]

When it does start, do the RPMs go up and down, and then it eventually die? Mine ended up being the fuel pump.

 

[boat]

Do you have any ideas? Other than telling me I am thinking too hard? lol

Your thinking too hard again... lol

Sometimes the RPM's go up and down, but it settles and smooths out, never has died when doing that. I have had the symptoms you speak of with another SHO, when the fuel pump was going out.

Fuel pump isn't it. I just replaced it back in July with a Walbro, and I have had this problem for well over a year.

FWIW, it was happening before I did my front 60k a year ago.

When it does start, do the RPMs go up and down, and then it eventually die? Mine ended up being the fuel pump.

 

[xshoel93x]

im no professional but are the plug wires connected right?

 

[bubba]

Yeah they are, and it runs like a ***** ape

im no professional but are the plug wires connected right?

 

[Shopower400]

I have nearly the same exact problem! I think i'm gonna try and replace the charcoal canister and see if that fixes it. Other than that though, she flys!

 

[RonJohn]

anybody find a solution? I have had the same problem for about year now...have to put the throttle about 3/4 down when cold then it will chug and fire up.. not all the time.. but alot more often lately..

 

[AREA 91]

Also, if it is talking about "low speed"....I believe that only the gen I's had a 2 stage fuel pump circuit. That is why the gen I's can run a larger fuel pump without having to get an aftermarket fpr. Have u changed your fuel filter? Is it when the car is hot or cold? When it does the hard start thing, does it stumble for just a second when you start it up? Mine will do this sometimes, but mostly when its hot. You may have answered these in the other thread, I didnt go back and read it.

The 89 and 90 sho's have the 2 speed fuel pumps.