Richk5

Hi all. Not sure what to check next but my recently acquired '91 tip has been giving me starting troubles. It turns over fine but just doesn't seem to want to ignite if that makes sense. To me it seems like a fuel supply issue but there are no problems once it gets running even at idle so I don't know if that could be the culprit. Usually I need to turn it over a 2-3 times before a start. Occasionally I can only get it to fire when to depress the accelerator while starting which it doesn't like and then takes a minute or so to even out the idle. Any tips of where you think I might try next?


Incidentally, I will be taking her in for some body work in the next week or two and will post pics after the makeover. I've always been a Porsche fan and I am truly in love with this car already. I get up sometimes and just go look at it in the garage so happy that I have it. It makes we want to run errands just so I can take a ride. Being a targa top this is the best time of year to be enjoying the weather in Louisiana.

Thanks in advance for any feedback

joey bagadonuts

Have you replaced the DME relay? That's usually a good place to start. It's also good to have a spare, even if that doesn't turn out to be the issue, so there's no downside (aside from having to buy one).

IME, your problem does sound like a bad DME.

Richk5

DME relay is new and a spare is on hand. Same issue with either of them plugged in. Not the culprit this time around I guess.

carlskisWP

Does the hard start happen when the engine is cold, hot, warm, random, or regularly?

Mine will be real hard to start occasionally if the engine is hot and then cools a bit over 1/2 to 1 hr. When that happens I have to crank for close to 10 seconds to get it to start (or sometimes floor accelerator). Never happens cold or hot. Research indicated it might be lost pressure in the fuel injectors, but I've learned to live with it.

So, to your problem maybe loss of fuel pressure somewhere in the system from sitting?

Richk5

Interesting. I get the best starts completely cold or really hot as if I only had it shut off for a minute to run into the store or something.

power_up

I had the starting issue when engine is shut down few minutes to 45 minutes. I live with it for 3 years. At the end, even cold start is not success in one go. I replaced the fuel pressure regulator last November, all starting issue gone. Hope this help.

LPMM

Does it run rich as well? If so it may be your fuel pressure regulator and a shop can diagnose this in no time. Best to replace it before it fails if it is the culprit, or else you can have quite a mess on your hands.

Richk5

Does run a little rich. Seems like fuel pressure regulator would make sense. thanks for the tips. How difficult is that to replace myself? I'm becoming more skilled because I enjoy working on the car myself but don't want to bite off anything I shouldn't just yet.

robt964

It sure is something you can do yourself however getting at the FPR is the tricky bit as it lives directly underneath the inlet plenum. If its unions from connecting pipes have never been loosened they'll need good bit of leverage to crack the nuts. Having very little room to move around under there makes this difficult to do. If you find that you just can't get the leverage, there are a few other possible solutions. You can remove the whole inlet plenum (bit of a faff) or undo the other end of all the hoses leading to the FPR, slide it out as an assembly and work on it on the bench. The unions on the ends of the fuel rails are easier to get too.

Richk5

Well guys, once again thanks for the help. Turns out it was indeed the FPR. I'm glad it was giving me trouble starting so it was noticed. When I investigated I found it was leaking fuel there so could have been a bigger problem obviously. It's all changed and starting up now on the first go like a charm. It was not fun trying to get to it to change it but it was nothing some time and a few swear words couldn't get me through.

Car fixed, Liverpool win, Saints win(in progress), and hurricane threat averted makes for a pretty good weekend.

robt964

Nice work