installed FD fuel pump now harder to start
#1
Full Member
Thread Starter
Join Date: Aug 2001
Location: Philadelphia, PA
Posts: 54
Likes: 0
Received 0 Likes
on
0 Posts
installed FD fuel pump now harder to start
Hey guys,
I installed a FD fuel pump, midpipe and fcd over the weekend on my 90 T2. Now when I start it up, instead of starting right away I have to hold the key turned to let it crank over for a while and it will finally start, but it will idle really low and alost die until I hold the throttle for a little bit. After that it runs great, the idle might be a little bit lower than before, but not much.
I have searched about it and am not sure if I need to let the ecu reset and learn again by driving it a lot. Before I changed the pump out it was perfect, idle right at 750 and start up at the very beginning turn of the key.
I had installed an intake a few weeks ago and noticed the idle lowered than when it started, but after a little bit it was back to normal. I have gone about 80 miles since the changes and it is still hard to start.
If you guys have any info I would apreciate it.
Oh yeah, my other mods are just downpipe and catback.
I installed a FD fuel pump, midpipe and fcd over the weekend on my 90 T2. Now when I start it up, instead of starting right away I have to hold the key turned to let it crank over for a while and it will finally start, but it will idle really low and alost die until I hold the throttle for a little bit. After that it runs great, the idle might be a little bit lower than before, but not much.
I have searched about it and am not sure if I need to let the ecu reset and learn again by driving it a lot. Before I changed the pump out it was perfect, idle right at 750 and start up at the very beginning turn of the key.
I had installed an intake a few weeks ago and noticed the idle lowered than when it started, but after a little bit it was back to normal. I have gone about 80 miles since the changes and it is still hard to start.
If you guys have any info I would apreciate it.
Oh yeah, my other mods are just downpipe and catback.
#5
HAILERS
Join Date: May 2001
Location: FORT WORTH, TEXAS,USA
Posts: 20,563
Likes: 0
Received 21 Likes
on
19 Posts
Can I suggest the FD fuel pump is possibly overwhelming the fuel pressure regulator and now you are seeing a higher rail pressure at the rail during start which in turn is flooding the engine. Just put a fuel pressure gauge on the inlet line to the engine and compare with the factory reading which is about 37psi. That 37psi is a guess. I've never seen 90 whatever manual, but on a 87, 88 it is about 37psi with the vac hose off the fuel pressure regulator during idle or around 28psi with the engine at idle and the vac hose connected.
#6
Full Member
Join Date: Nov 2001
Location: Melbourne, FL
Posts: 149
Likes: 0
Received 0 Likes
on
0 Posts
Originally posted by HAILERS
Can I suggest the FD fuel pump is possibly overwhelming the fuel pressure regulator and now you are seeing a higher rail pressure at the rail during start which in turn is flooding the engine.
Can I suggest the FD fuel pump is possibly overwhelming the fuel pressure regulator and now you are seeing a higher rail pressure at the rail during start which in turn is flooding the engine.
The car does run higher rail pressures at idle, so you may have a hard time starting it when it is hot, but mine has always started quick when it is cool.
It could still be the fuel pump causing this, but this sounds like something else.
Of course the quickest test would be to swap the fuel pumps back and see what happens.
Later
#7
Full Member
Thread Starter
Join Date: Aug 2001
Location: Philadelphia, PA
Posts: 54
Likes: 0
Received 0 Likes
on
0 Posts
Thanks for the input guys. I will try to old pump when i get a chance and see what happens. Also, any recommendations on where to get a cheap fuel pressure gauge? I will try to give that a go too.
Trending Topics
#8
1.3 liters of whoop ass
iTrader: (11)
I put a third gen pump in my 90 t2 and never had one problem with it starting until..........I put a TT Supra pump in. Don't know why it starts hard now but it is the same problem you are having and i have had it on for almost 8 months and it still does it. just thought id let you know.
#9
Rotary Enthusiast
Your fuel pressure regulator might be damaged, replace it with an aftermarket one (Mallory is the way to go) set it between 35.9 and 37 psi...
Thread
Thread Starter
Forum
Replies
Last Post
trickster
2nd Generation Specific (1986-1992)
25
07-01-23 04:40 PM
immanuel__7
2nd Generation Specific (1986-1992)
89
09-05-15 10:23 AM