Hesitating above 6500...

[e30s52]

did you fix this problem?

[MR 325]

Matt,

Could you reply to this please?

Matt

Yes, it doesn't do it every time. I had this problem before the chip btw.

[matt]

Only once in a while?

Matt,

Could you reply to this please?

Matt

[static]

Haha, thanks for the advice. ;)

I will use the Mac fuel pressure gauge at work. Probably stick it under the windshield wiper and go drive it.

good idea!

[MR 325]

not sure what your measuring strategy will be, but make sure to test it at the troublesome rpm/load range (i.e 6500-7000 full load). i.e not just at idle, as that won't tell the story

Haha, thanks for the advice. ;)

I will use the Mac fuel pressure gauge at work. Probably stick it under the windshield wiper and go drive it.

[static]

No codes. I know the injectors are not the problem since it did it with the stock injectors and still does it with the S52 injectors. If I have time tomorrow I am going to test the fuel pressure.

not sure what your measuring strategy will be, but make sure to test it at the troublesome rpm/load range (i.e 6500-7000 full load). i.e not just at idle, as that won't tell the story

[MR 325]

No codes. I know the injectors are not the problem since it did it with the stock injectors and still does it with the S52 injectors. If I have time tomorrow I am going to test the fuel pressure.

[static]

i wonder if there is a way to check the duty cycle of your injectors during the troublesome rpm range - i read reports that original 17.5# inj are not enough for s50 with some high flowing mods (i.e approaching 100%) - are 17.5#'s what you have?

otherwise, as others suggested, changing fuel filter is always a good thing, and the pump may not supply enough pressure at the high volume required after 6krpm/high load
also may be something stupid like a kink in hard or soft fuel lines.

[broke30]

Does the car throw a code for it? And how sudden is the hesitation? Does it just "blip" in or is it long-lasting?
Max

[MR 325]

This is an S50.

Fuel filter, plugs, o2 sensor were all brand new when the motor was installed. Not sure of the pump's age, haven't touched it.

[BigD]

I'd say no, it won't work as a pre-pump.The one in the tank on early cars just transfers fuel without much pressure. The one he's talking about Is a higher pressure main pump, and you don't need 2 of those.

Cools, I'll stick to OEM. Thanks.

[DaN]

Could this pump work with an early, dual pump car? So it would work as the pre-pump? I've got both OEM pumps on order but they don't ship until tomorrow, I have time, pls let me know.

I'd say no, it won't work as a pre-pump.The one in the tank on early cars just transfers fuel without much pressure. The one he's talking about Is a higher pressure main pump, and you don't need 2 of those.

[e30this]

I had this issue with my m50 swap and it ended up being a bad combo of an 02 sensor and bad plugs.

[BigD]

fyi, a 1990 mustang 5.0 in tank fuel pump is less than $80 at any parts store and fits as a replacement for the e30 intank pump...

e30 intank pump is about $200 from dealer and about $180 for aftermarket

works great in my car

Could this pump work with an early, dual pump car? So it would work as the pre-pump? I've got both OEM pumps on order but they don't ship until tomorrow, I have time, pls let me know.

[JPStrniste]

fyi, a 1990 mustang 5.0 in tank fuel pump is less than $80 at any parts store and fits as a replacement for the e30 intank pump...

e30 intank pump is about $200 from dealer and about $180 for aftermarket

works great in my car