Car starts fine when cold takes a while to start when warm

[Stryker]

My car starts fine when cold first turn and off no problem despite length of time between starts However when warm it can churn for several seconds before starting.When started seems fine although I feel it is running bit rich fuel mixture wise. Is this possibly the temp sensor or something different ?. Thanks for any help with this in anticipation

[HJ2]

It could be the temp sensor indeed.

Although a lot of Elan owners, me included, experience the same problems.
I have all sensors involved replaced, no improvement.

It now doesn't bother me anymore. I know it will alway start, but it takes a couple of seconds

[Stryker]

Thanks for reply have read some other threads and wonder if its the fuel pressure valve which I gather is on the end of the fuel rail so would like to try that if anyone can help me source one ???

[Brit-Car-Nut]

The most common part number is PR92 or PR92T where the T is a bulk packaged version as compared to the retail packaged version.

Rock Auto www.rockauto.co.uk shows them for £26.19 and £20.92 respectively.

You might find a better price if you google, check amazon or check eBay.

All of the regulators now available have the vacuum nipple at the top instead of the side but some have bent the nipple or drilled an access hole in the lift bracket.

[HJ2]

What would the fuel regulator have to do with a fuel-rich hot start?

[Brit-Car-Nut]

If the FPR isn't regulating, the pressure can be too high and will basically act like the choke is stuck on.

See viewtopic.php?f=37&t=21631&start=20#p272125

I know his issues were extreme but a over-pressure system will be hard to start hot.

[Ted]

I didn't knew this site existing (www.rockauto.com)
How can they sell the FPR only 26£ when Steve's sells it 125£?
Is it the same part?
I'm looking after a FPR and I don't have 125£ now...

[ashm]

I used to have this:
- fine starting when cold
- fine starting when left for >30 mins, even if still hot
- fine starting immediately after stopping
- 5-10 seconds cranking if starting hot after < 30 mins stop, then a couple of seconds stumbling & very rich running, then fine.


- new temp sensor, no change
- new leads, no change
- new plugs, no change
- new MSD coil packs, no change
- new fuel pump, no change
- new fuel filter, no change
- new fuel pressure regulator, injectors professionally cleaned, refurbished and tested, problem apparently fixed!

I reckon either the fpr was holding the pressure too high leading to overfuelling until the ECU kicks in,
or more likely the injectors were leaking; when the engine stopped, excess fuel was getting in until the rail pressure dropped, but if the car was sat for a little while it would evaporate away again and be fine.

Of course, many different faults could cause similar symptoms, your mileage may vary!

Adam

[Ted]

I think I will start with change the FPR and if it doesn't fixe the problem, I will check the injectors.
But how doesn't rockauto do to be so cheap?

[HJ2]

OK Adam, you convinced me
I'll order an FPR right away!

[Ted]

OK Adam, you convinced me
I'll order an FPR right away!

Were will you order it?

[HJ2]

There are multiple threads about FPR's.
Main issue is for most of them you will need to modify or ditch the engine hoist bracket.
For me that is not a problem.

[Ted]

Excuse me, but is this FPR (http://www.rockauto.co.uk/catalog/morei ... cc=1176173) the same as the original one?
It's not easy for me in France to find parts

[HJ2]

France will not be any harder that the Netherlands when it comes to parts

Nope...
The vacuum line should be on the side.
Look & contribute here:

viewtopic.php?f=46&t=14939

[Brit-Car-Nut]

Excuse me, but is this FPR (http://www.rockauto.co.uk/catalog/morei ... cc=1176173) the same as the original one?
It's not easy for me in France to find parts

Unfortunately, YES. The version with the vacuum nipple on the side is no longer available. Rock Auto is a parts wholesale company where SJS is a parts retail company. You also might be able to find the FPR on eBay?

This is how I solved the vacuum nipple problem: viewtopic.php?f=46&t=14939&start=20#p277560

[Ted]

Excuse me, but is this FPR (http://www.rockauto.co.uk/catalog/morei ... cc=1176173) the same as the original one?
It's not easy for me in France to find parts

Unfortunately, YES. The version with the vacuum nipple on the side is no longer available. Rock Auto is a parts wholesale company where SJS is a parts retail company. You also might be able to find the FPR on eBay?

This is how I solved the vacuum nipple problem: viewtopic.php?f=46&t=14939&start=20#p277560

Why do you say "unfortunately"??

[Brit-Car-Nut]

Unfortunately, because it is the only NEW FPR available and the location of the nipple is a pain. You can leave off the lifting eye or drill it to allow the hose to pass through it. The side entry version has been out of production for at least 6 years, so any you find, regardless the price, will be at least that old and the rubber diaphram is also that old.

It would be nice if GM continued using a FPR with a side entry nipple, but they didn't, so you can only get the new version of the FPR that fits (and is used by) current/newer model vehicles.

I would have the injectors professionally tested, cleaned and verified trather than try to clean them yourself. I know it will take a few weeks longer if you have to send your injectors to RC Engineering, but you will know for a fact that they are not a problem when you move forward with your repair. $100.00 for all 4, not including shipping, is a reasonable price and their service is very good.

[HJ2]

Solved! (i hope)

Just for the record: I did not install a fresh FPR yet, but i did swap the injectors for a new set!
It appears as if the hot start problems are gone! Perhaps one of the injectors was a bit leaky, causing one cylinder to run rich and also fooling the lambda sensor that there is too much fuel so the mixture is adjusted lean in the other 3 cylinders as a consequence... (just thinking out loud here...)

I will be keeping an eye on things before i declare this one as 'solved'.