My car starts perfectly fine and fast when its completely cold but after driving it and having it stopped for 1-2 hours (so engine is still warm), it struggles to start, takes like 3-5 seconds turning and I give a little gas too. It is a street ported engine, is that normal? Thanks. List of mods follow...

rebuilt engine with street port and 3mm apex seals
upgraded Bully clutch
Walbro 255lph fuel pump
dual filter K&N intake with heat sheild
3'' down pipe and 3'' cat back exhaust
Pettit ecu
H&R sport springs
Hawk hp plus brake pads
Apex-i turbo timer
Autometer boost gauge
Brand new tires 245/45/16
Brand new OEM rad 500km ago
Clarion head unit with 4 clarion speakers
Pivot headlight controller (sleepy eye look)
strut tower brace

thewird

 

Sometimes trouble with warm starts can be blamed on a low compression engine. Since your engine seems to have been rebuilt it could have been clearance improperly or just worn how housing and plates. If you have the tools handy give it a check and see if you can eliminate that option.

 

Its not normal. Another problem could be your FPR solenoid.

 

what kind of vacuum are you pulling at idle, and what idle rpm?

 

I've been having the EXACT same problem and I too have a street ported engine. Also if i let the RPMs drop too low, the car stalls from time to time. Does that happen to you too? I cant seem to figure out the problem.

 

+1

 

what's an FPR solenoid?

 

Its used to increase pressure in aiding to avoid vapor lock during hot starts.

 

My stock reman starts fine on a hot engine but the idle will hunt and it will sometimes stall from this. The idle usually goes back to normal after I take off and drive for a little while.

 

It idles at 0.9-1.4k RPM, when its at 1.4 if I accell a little bit it drops to the normal 0.9k RPM. The car never stalls during idle. The vacuum is ~16. The engine was rebuilt by Mazdees which is a rotary specialist in the GTA area.

thewird

 

Thanks! What does the acronymn stand for though? Fuel pressure regulator?

 

yup.

thewird, that vacuum (16 inches at 900 rpm) is fine for a ported motor. I would say you have a tuning issue, but with the pettit ecu that isn't really possible. It wouldn't hurt to swap out your plugs and wires, and possibly your coils. I've seen instances where the leading coil will crap out once it's hot.

 

Is that something I could do or do I have to take it to my mechanic? I've never done any engine work except for check the oil, add washer fluid >_>, and I've changed tires before too. If its just unscrewing something and putting in a new one I could do that but I don't even know where to look for any of those things mentioned. Of course I'm willing to learn because I'd like to do some things myself on my FD.

thewird

 

You'll have to remove the Upper Intake Manifold to get at the coils, and on a stock car that isn't very fun. When was the last time your plugs and wires were changed? If it's been awhile, it can't hurt to have new ones installed. New coils are very expensive, better to find a good/low mileage used one (make sure you get the leading one, located in the middle of all three coils). Anyway, based on your wrenching experience I'd say take it to your mechanic.

One last thing: I'm just making an educated guess. It may not be the coil......

 

How would I check if its this? I'm just trying to see if I can find the problem myself before I take it to the mechanic. This is the first car I actually care about.

thewird

 

thanks Rich

I think mine is going... I have (and always had) 14 inches (mild streetport) of vacuum at 850 RPM, but lately the car has been giving slight trouble at hot starts. Just like the thread starter.

 

The FSM shows the test procedures:

 

Ok, I'm gonna check the FSM. Also correction on the vacuum, it idles at 10-11. I assume thats better.

thewird