Startup Gremlin after 1-2 hours parked.. Any thoughts?

[norcimo]

Hi,

There is one thing I can seem to find the fix.. Is this startup issue, where it just won't start, and when it does it hesitates., you almost kill the battery for
constantly cranking.. does it occasionally...depends on how long it sat.

IT does this after I go for a 20-30 minute ride.. I park the car...spent a 1 hour or 2..."eating"...whatever, when I come back, has problem starting.
Don't get me wrong, it will start eventually, it just fight me... like it was vapor lock or something...

Can not seem to find the problem, because its very specific... This is what I know:

1. Car over night Garage, in the morning , starts right up.. NP.
2. No idle issues.
3. Plenty of Power.
4. Not running rich nor too lean.
5. Runs while cold or warm engine.
6. No idle hunting.
7. voltage is great, system changing.


I read that a relay upgrade can fix this issue? Any help will be great.. thanks

[gulwng3]

Have you ever replaced your fuel accumulator? Same thing happened to me, but only when above 80F in the summer.

Andy

[norcimo]

Have you ever replaced your fuel accumulator? Same thing happened to me, but only when above 80F in the summer.

Andy

Hum.. I'm going to have to check the service records.
If that is the case, thats an easy fix.

I will check.

Thanks

[norcimo]

Hum.. I'm going to have to check the service records.
If that is the case, thats an easy fix.

I will check.

Thanks

I talked to my mechanic,
he doesn't believe it can be the full accumulator..,the car starts in the morning or anytime. Its these short trips after 1-2 of hours sitting thats the issue.
he checked the pressure in the fuel system, its where it suppose to be.

[Jonathan]

I talked to my mechanic,
he doesn't believe it can be the full accumulator..,the car starts in the morning or anytime. Its these short trips after 1-2 of hours sitting thats the issue.
he checked the pressure in the fuel system, its where it suppose to be.

With all due respect to your mechanic, he is wrong. Everything you described sounds like classic fuel accumulator/hot start problem.

It isn't the easiest thing to change out though, contrary to what you said, so you could do some experimenting to try and confirm this is indeed the problem.

What you want to determine is how long after turning off the car the resting fuel pressure remains. A good accumulator will keep the fuel lines at the engine pressurized in upwards of three hours after you shut off the car.

To test this, you need to be able to remove the air filter housing and have access to the plate underneath. So, drive your car, get it warm like you normally would from using it, and then once you are home, park the car, shut it off, remove the air filter housing, and then gently push down on the plate with your finger.

What you are trying to get a sense of is when it becomes easy to push it down, i.e. there is not resistance behind it. That resistance is your resting fuel pressure. From what you said, I would guess it will remain there for about 15 minutes tops, and then it'll be easy to push down on the plate. It should feel like there is resistance at the plate against your finger for two hours at least. If it is more like 10, 20, 30 minutes, the problem is your accumulator.

In the meantime, double check the electrical connections on your ballast resistor. One or more of those wires not quite connected well, could cause you intermittent starting problems as well.

[Bitsyncmaster]

You can test how long you are holding rest pressure. In the summer time I say you need to hold rest pressure for 4 hours or longer. Yes I know the book only specifies a rest pressure after 10 minuets.

If you are holding rest pressure for one hour or more than my RPM relay can be jumpered to extend your rest pressure time another 3 hours.

My car will hold rest pressure for about 3 hours. If I tried to start the car at 3.5 to 4.0 hours after shutdown in the summer, it would not start. It would start fine before the 3 hour or after 4 hours of shutdown. That is the reason I designed my RPM relay with that fix.

[norcimo]

With all due respect to your mechanic, he is wrong. Everything you described sounds like classic fuel accumulator/hot start problem.

It isn't the easiest thing to change out though, contrary to what you said, so you could do some experimenting to try and confirm this is indeed the problem.

What you want to determine is how long after turning off the car the resting fuel pressure remains. A good accumulator will keep the fuel lines at the engine pressurized in upwards of three hours after you shut off the car.

To test this, you need to be able to remove the air filter housing and have access to the plate underneath. So, drive your car, get it warm like you normally would from using it, and then once you are home, park the car, shut it off, remove the air filter housing, and then gently push down on the plate with your finger.

What you are trying to get a sense of is when it becomes easy to push it down, i.e. there is not resistance behind it. That resistance is your resting fuel pressure. From what you said, I would guess it will remain there for about 15 minutes tops, and then it'll be easy to push down on the plate. It should feel like there is resistance at the plate against your finger for two hours at least. If it is more like 10, 20, 30 minutes, the problem is your accumulator.

In the meantime, double check the electrical connections on your ballast resistor. One or more of those wires not quite connected well, could cause you intermittent starting problems as well.

ok. My course of action will be then:

1. check the records to see if the accumulator has been in fact replaced.
2. if has not, order the part. install it and done.

3. If has been replaced. Do the pressure test. with the flap.

Observation. ( this has only happened after one hour or so) , 10, 20, 30 minutes. its start right away. I test and get back to you.

Thanks for all your help.

[Jonathan]

ok. My course of action will be then:

1. check the records to see if the accumulator has been in fact replaced.
2. if has not, order the part. install it and done.

3. If has been replaced. Do the pressure test. with the flap.

Observation. ( this has only happened after one hour or so) , 10, 20, 30 minutes. its start right away. I test and get back to you.

Thanks for all your help.

I would be inclined to do the test on the rest pressure first. Checking records won't change whether your accumulator is a problem or not. It might make you wonder why it failed (again) if it was already changed out, but it won't fix your problem.

When my own accumulator gave up the ghost, I could get away with stopping for up to 30 minutes, but not more. If my stop for lunch or whatever took more than 30 minutes, I knew I was going to need to wait another 2 hours to be able to start the car again. There are a lot of variables in what these times are and why yours is what it is and mine was what it was. It's usually the same solution though.

If you do determine the accumulator needs changing, and you go back into your mechanic to get his help with it, be polite about telling him he was wrong so not to bruise his ego. I say that because you'll also need to remind him to be gentle on working with the nuts securing the hardlines and hoses. Ask him to make certain those hardlines are not getting twisted at all when he puts some force on the nuts to get them loose. Those hardlines like to be twisted about as much as the trip reset shafts do. And fixing that problem is even less fun.

[smcguiga]

I had the same exact problem as you are describing. It would fire up fine cold and if sat for more than a few hours it would fire back up just fine but there was a time between sitting for around 45 minutes to 3 hours and it would take a long time to crank. I changed out my accumulator and the problem is now gone. The hardest part was removing the hard line, once that nut was cracked I removed the four bracket bolts, remove the other lines, waited what seemed like forever for fuel to stop draining out and then put the new one on. It starts right up every time now. The one I removed was from SpecialT and had 12/12 scratched on it, so it had been replaced a few years ago but had a lot of trash in the back line. The one I got from DMCH was a little bigger.

--Steven

[funkstuf]

I have had this problem and replacing the accumulator did solve it.

[Ryan S.]

Search 'hot start' and you will see bunch of postings describing your symptoms.
Common solution is to replace an accumulator. It's a PIA job so you may want your mechanic to do this.

fuel pressure gauge can also diagnose source of your problem.

[sdg3205]

There are a number of places where failure would cause hot start issues:

1. Accumulator
2. Fuel pump check valve
3. primary pressure regulator o-rings
4 leaky injectors
5 I forget the fifth

I have had hot start issues with 1, 2 and 3. You need to measure rest pressure. Once you confirm you are loosing rest pressure you can begin to test each component. A bad check valve for example drops rest pressure very quickly. The PPR and accumulator tend to trickle down more slowly IIRC.

Edit - 5 is a leaky cold start valve IIRC

[norcimo]

Thanks

[norcimo]

There are a number of places where failure would cause hot start issues:

1. Accumulator
2. Fuel pump check valve
3. primary pressure regulator o-rings
4 leaky injectors
5 I forget the fifth

I have had hot start issues with 1, 2 and 3. You need to measure rest pressure. Once you confirm you are loosing rest pressure you can begin to test each component. A bad check valve for example drops rest pressure very quickly. The PPR and accumulator tend to trickle down more slowly IIRC.

Edit - 5 is a leaky cold start valve IIRC

Question,

When setting the mixture, what should be the RPMS? during the setup?

Thanks

[Bitsyncmaster]

Question,

When setting the mixture, what should be the RPMS? during the setup?

Thanks

I think the book says set 950 RPM but I've found just do it with 775 and the mixture does not change with higher RPM.

[norcimo]

Problem Fixed.

one clogged injector.. I did the mason jar test.. Number 3 barely vaporizing. All the others were great. This was a new injector

so cleaned it with brake cleaner.., it worked... tested,, pattern came back and is all good.

Also... one bad O2 sensor... got one from Amazon for 8 bucks. man was my dwell off! WOW!

ok.. fixed that , Nice idle at 775-800 Rpm.. no hunting.. and dwell meter oscillates between 38-44, mostly hitting 40 on average. and rich smell is gone.


car starts on the spot after two hours ...great!

OPINIONS please?

[Jonathan]

Hi,

There is one thing I can seem to find the fix.. Is this startup issue, where it just won't start, and when it does it hesitates., you almost kill the battery for
constantly cranking.. does it occasionally...depends on how long it sat.

IT does this after I go for a 20-30 minute ride.. I park the car...spent a 1 hour or 2..."eating"...whatever, when I come back, has problem starting.
Don't get me wrong, it will start eventually, it just fight me... like it was vapor lock or something...

Can not seem to find the problem, because its very specific... This is what I know:

1. Car over night Garage, in the morning , starts right up.. NP.
2. No idle issues.3. Plenty of Power.
4. Not running rich nor too lean.5. Runs while cold or warm engine.
6. No idle hunting.7. voltage is great, system changing.


I read that a relay upgrade can fix this issue? Any help will be great.. thanks


Problem Fixed.

one clogged injector.. I did the mason jar test.. Number 3 barely vaporizing. All the others were great. This was a new injector

so cleaned it with brake cleaner.., it worked... tested,, pattern came back and is all good.

Also... one bad O2 sensor... got one from Amazon for 8 bucks. man was my dwell off! WOW!

ok.. fixed that , Nice idle at 775-800 Rpm.. no hunting.. and dwell meter oscillates between 38-44, mostly hitting 40 on average. and rich smell is gone.

car starts on the spot after two hours ...great!

OPINIONS please?

Your initial problem description and stated facts don't match your description of the solution and things you corrected.

Glad you fixed it, it just makes it difficult for someone to offer help or suggestions when the details aren't consistent.

[sdg3205]

Your initial problem description and stated facts don't match your description of the solution and things you corrected.

Glad you fixed it, it just makes it difficult for someone to offer help or suggestions when the details aren't consistent.

+1

Glad you're back on the road, but one semi- clogged injector would lead to a terrible running condition and have harder starts across the board with no regard to hot or cold conditions. You may still have a problem, but have come across another issue in the process.

[A Van]

Few guys over here have seen warm start issues lately, with hot and cold starts fine.
The culprits have always been injectors leaking at rest and not holding pressure.
Quick test pop the injectors out after 30 mins after a run, if one or more comes wet , there is the problem.

[norcimo]

Kudos to the Upgrade RPM relay.

My engine starts on the first crank. No matter how long its sits between trips..

Simply amazing.

Thanks.

[StanMan PushN 88]

Kudos to the Upgrade RPM relay.

My engine starts on the first crank. No matter how long its sits between trips..

Simply amazing.

Thanks.


QUESTION: What is this "Upgrade RPM relay" you speak of and what's the advantages of getting one? Part #? Source? How easy/hard is it to swap out? Any soldering involved?

Thanks!

[DMC-81]

QUESTION: What is this "Upgrade RPM relay" you speak of and what's the advantages of getting one? Part #? Source? How easy/hard is it to swap out? Any soldering involved?

Thanks!

Hi there,

Dave McKeen (Bitsyncmaster) sells them. See post 15 in this thread for his website. It is a solid state design. The originals can get hot and fail. It is plug and play, no soldering required. I have it and it's great.

In this picture, The original is on the left, and Dave's is on the right....
44223

Cheers,