Hesitating above 6500...

[MR 325]

Once is a while when I take the car to redline it will start to hesitate starting anywhere from 6200-6500 and all the way to redline. I'm wondering if anybody has had anything like this go on with their cars and what may cause it.

I'm thinking it's a fuel issue but of course haven't really looked in to it much at this point. It's definitely not a bad ground to the engine or coils. The wierd thing si I have been driving this car since November with the motor and this has only started to happen in the last couple weeks.

[BigD]

How old is your fuel pump/filter? Me and windsor318is are having an extreme version of that. He knows it's his pump, I'm 99% sure it is (and/or filter).

[matt]

Only once in a while?

[e30polak]

If it's not fuel, it might have something to do with vanos?

[dark89e30]

Ignition. OE plugs? VCG?

[DCColegrove]

What engine are we talking about?

I've had M52's and TUs float valves at high rev's when the oil was nasty.

Bad coils, plugs etc can do it too under heavy load.

[scabzzzz]

In my M52 swapped car, my fuel filter was dirty and it did that. I had stock programming as well.

[e30s52]

If it's not fuel, it might have something to do with vanos?

its not vanos my m50 non-vanos did the same thing. i just replaced the fuel filter and it stoped.

[windsor318is]

i think its a combination of pump and filter, we are forgetting how old these cars are. and its been awhile im sure since people have changed there filters.

[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

[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.

[e30this]

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

[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.

[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.

[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.