mmjb

ok so i have a 1988 tii with removed emissions (emission removal taken from rotory resurrection), new rebuilt motor w/ 30 miles on it. I did rebuild myself, compression is 90 on both front and rear rotors. brand new injectors, and fuel filter. I'm having hot start problems. Cold starts fine but when normal operating temperature is reached i can not start the car. pulled spark plugs to check for flooding after engine is shut off when warm, and there is no flooding. I'v tried the fuel cut switch, but the engine will come very close to starting, but won't start up. When cranking engine i made sure battery was fully charged also. I'm useing 10w30 oil, i'v heard oil may make a difference. any help/input would be appricated.

stacher

I would suggest you check for a bad sensor

mmjb

I'v checked error codes, and fixed any codes that came up. I also have a new O2 sensor.

stacher

There will be no error codes. Check your water temp sensor (broken, not connected, etc). While you at it check all other sensors.

djmtsu

iTrader: (3)

Mine does the same thing and it now has about 400 miles on it. I was told it should go away or get a little better once the engine is fully broken in. All my sensors are plugged in and there are no error codes. Hmm, whats the deal.

mmjb

all sensors work fine, and are hooked up. I check my plug wires, and found they are off spec by a few ohms, so im going to replace them. The car had originally 150k on it b4 for i got it, and rebuilt it. I needed new injectors and fuel filter. I'm thinking maybe it needs a new fuel pump also. Could a bad fuel pump contribute to my problem? Also have a bad hesitaion problem at WOT. I'v Set the TPS, and Made new grounds/ connect all stock grounds.

J-Rat

iTrader: (2)

Unplug your waterthermosensor and go see what happens..

It will throw a code... I have verified that time and time again.

Possible reasons for hot start (for the 100 millionth time..):

1. Lack of tune up.
2. Possible failing EGI sensor.
3. Possible leaking injector
4. Possible low compression
5. In extreme cases possible bad ECU.

AJU

was just wondering what kind of oil you are useing to break the motor in ? ive always broke every engine that ive put together in on non detergant oil .. because detergant oil can cause cylinder glazing witch could be oil soaking the plugs when its hot ...just a thought

NZConvertible

In that case you also removed the Hot-Start Assist System, and that probably explains why...

The FPR solenoid was there to prevent this.

mmjb

ah i see...... i should have thought about what i was removing before i started my emissions removal. So now that i know i need the hot start assist system back, what do i need to do this?

1. Im guessing the FPR valve thats on the secondar rail.
2. The FPR solenoid (number 3, orange).
3. Any vac lines, and any electrical connectors.

NZConvertible

The solenoid valve needs to be plumbed inline between the manifold (the angled nipple on the inside of the LIM) and the FPR. The solenoid must be oriented correctly; see the schematic in the FSM.

I'm assuming you don't have low compression or leaking injectors, both of which will cause hot-start problems with or without the FPR solenoid working.

--MAstermind--

i dont wanna thread jack but im having the same troubles and didnt wanna start 2 of the same thread....

my car was compression tested at 95 both rotors all faces about 5 months ago...(with good care and occational spirited driving) would my compression drop in 5 months? it takes about 5 turns of the key to get it going....(i know one of my secondary injectors is kinda messed up but i dont smell fuel...) sometimes i have to turn the key about 3 times before it attempts to crank...see lights dimm out and the fuelpump whines a little but the car doesnt crank somtimes still about 3 trys then it attempts to crank....i have to try to have it crank about 3-4 times before it acually kicks on my cold start assist is pretty whacked out becuase when its cold it will go to 3k then drop and hold it at like 2`1.5K FOR A LONG TIME until it drops slowly back down...to 750~800....ontop of that the car hesitates at around 3800-4k...could all of this be realted in some way? now my car always starts...just it now always has trouble after its warm when its cold it starts up FAST....i have the air pump removed,....thanks and i hope i can get this resolved....(sorry if i thread jacked!)

mmjb

ok before i go and start putting the FPR soleniod back on lets think about something here. The soleniod just decreases fuel pressure during a hot start? So if i have a fuel cut switch to cut the fuel when starting, wouldn't that bypass the hot start system?

NZConvertible

Sounds more like a battery problem.

No, it increases fuel pressure.

The system operates during cranking and for 50 seconds after starting.

--MAstermind--

batter is tested its good pushin close to 13....i dunno what else it could be because all of a sudden my car now starts first try agian...i tightend the alternator belt...is was drooping because of that washer that goes behind it was missing...(stupid friends lost it) well....other than that the car seems better thanks for the intel...but i do guess that my temp sensor thingy and O2 sensor are busted...should taht water temp sensor at the water pump spin i can spin it...(not the nut but the little red connector spins inside it...)