Hard starts...Im going CRAZY!!

[ghostbuster88]

Hope someone can help me find a solution that has been driving me nuts. About 2 years ago i seafoamed my previa thru the brake booster vac hose. Ever since then my Previa would have trouble starting. It would crank for about 5 seconds and then start up. Last month I replaced the fuel pump (gas milage is exponentially better), it starts right up more often sometimes, but other times when I go in somewhere and come out a half hour later it still cranks a lot then starts.

Did a tune up after the problem started, no change

Spark plugs are normal and getting spark

changed out fuel filter

tested iacv and ign coil, both are within ohm spec so theyre good

new fuel pressure regulator



going to test distributor and maf tomorrow

What do you think it may be? Please let me know. Thanks!

[timsrv]

Excessive cranking is usually an indication of fuel draining back into the tank after shut-down. The 2 parts that work together in preventing this are the fuel pump (check valve inside) & the FPR (Fuel Pressure Regulator). Since you already changed the fuel pump, then it's likely the regulator is bad. On the Previa it's easy to change, but you need to remove the passenger seat & the engine access panel for access.

It's always best to test fuel pressure and watch for "leak-down" after shutting the engine off, but if you don't have a way to do that it might be worth taking a chance & just swap the FPR. Good luck. Tim

[ghostbuster88]

The FPR is brand new from toyota got replaced about 3 months ago.

[timsrv]

Sorry, missed the part about the new FPR. Perhaps your cold start injector? Try disconnecting it to see if anything changes with start-up times.

[ghostbuster88]

Did that, both unplugged and plugged is same thing. Checked MAF today and it was good. Wonder if I may have a vacuum leak. I've been hearing a hissing around the throttle body diaphragm plunger area. I moved my fingers around it and it's around there

[timsrv]

If it runs decent after it starts, then it's not likely a vacuum leak. I think you should rig up a fuel pressure gauge so you can see what's happening with the fuel pressure after shut-down. Tim

[ghostbuster88]

Ill do that and let u know thanks. Also i have read stuff about the circuit opening relay. Whats the ohm spec for that? Wanna rule it out.

[timsrv]

That's not likely the problem. Relays typically work good or not at all. A faulty open circuit relay wouldn't create the sort of problem you are having. Tim