Fuel pump maybe?

[DSM_Newblet]

So I've had my 97 gsx for about a year now and it has always had an overheating problem even after the 6 bolt swap and i can't figure out why it is overheating, I've checked EVERYTHING literally. But now after about 30 min of driving it does it's thing, temperature rises, a/c blows hot, yada yada and it is now accompanied by a strange almost motorcycle sound like a lawn mower and gets very rough on the ride by vibrating like hell and i can just feel a gigantic power loss. I can still take it to over 6k rpms but i choose not to for obvious reasons. So my question is why does it do this (the sound and vibration)? Right now it is rough tuned on 1000cc injectors and 91 oct gas and supporting mods. I know 1000cc is alot for 91 but it runs good when it doesn't overheat and I am about to get it tuned for e85 so I just had my buddy rough tune it until I get the e85 tune done.

I have a sound recording on my cell phone but have no idea how to uplaod it because it is an .amr file...

I just took it to the gas station to get some cigarettes which was about a 15min drive and it happened to me about 10 times without over heating. I also noticed that when it happens the car leans out ALOT, My aem wideband can't even pick it up because it is 18+ A/F R. And I am also able to turn my car off then restart it and the problem goes away for about 2min. I'm so confused Any help please?

 

[BIRDCLAWTSi]

The running rough sounds like a maf issue, Can you see the Hz. on the logger when it happens? Over heating can be a result of a bad t stat, Radiator issue, cooling fans not kicking on, If it's doing it on 2 different motors, Sounds like an external problem as mentioned above. Can you put a fuel pressure gauge on it and watch it while you drive? It could also be a missfire, Spark plug wire arcing out, Or coil pack, Power transistor could be going bad, Check your plugs and see if one or all is black with soot. Spray water on the wires and coils with a spray bottle in the dark and look for sparks. you can spray the transistor too, See if the car runs rough. Edit: could also be the ecu. Leaking caps, ETC...

 

[95'RS-T]

That lawn mower sound you hear is most likely an exhaust leak. You might want to do a boost leak test. As for your over heating issue, your coolant is probably not full. Did you fill the radiator while the car was running to get all the air out?

Edit: just looked at your profile mods. It don't say you have a afpr, do you have one?

 

[DSM_Newblet]

That lawn mower sound you hear is most likely an exhaust leak. You might want to do a boost leak test. As for your over heating issue, your coolant is probably not full. Did you fill the radiator while the car was running to get all the air out?

Edit: just looked at your profile mods. It don't say you have a afpr, do you have one?

I have just a stock afpr and it's not an exhaust leak it sound like just TONS of back fire and bogging.

The running rough sounds like a maf issue, Can you see the Hz. on the logger when it happens? Over heating can be a result of a bad t stat, Radiator issue, cooling fans not kicking on, If it's doing it on 2 different motors, Sounds like an external problem as mentioned above. Can you put a fuel pressure gauge on it and watch it while you drive? It could also be a missfire, Spark plug wire arcing out, Or coil pack, Power transistor could be going bad, Check your plugs and see if one or all is black with soot. Spray water on the wires and coils with a spray bottle in the dark and look for sparks. you can spray the transistor too, See if the car runs rough. Edit: could also be the ecu. Leaking caps, ETC...

Thank you this was a big help but that is alot of stuff to check and I have little time would it narrow it down if I said the problem disappears when I turn the key off then back on?

 

[montm82]

for the over heating it can be a couple of things, such as bad water pump, bad hoses, radiator cap, or even head gasket. do a leak down test. then eliminate that problem. oh and do a compression test while you are there, check the timing. just a list of things i would go over.

 

[BIRDCLAWTSi]

I have just a stock afpr and it's not an exhaust leak it sound like just TONS of back fire and bogging.



Thank you this was a big help but that is alot of stuff to check and I have little time would it narrow it down if I said the problem disappears when I turn the key off then back on?

I would look into the ignition stuff first, Spray water on the wires and coils and see if it acts up, And look for sparks. Let it cool down and check the spark plugs. Not sure why shutting it off would help. Do you hear clicking or anything from inside the car wierd smell?

 

[95'RS-T]

Someone please correct me if I'm wrong. A walbro 255 pump requires a afpr. Your stock fpr is being over run.

 

[BIRDCLAWTSi]

Someone please correct me if I'm wrong. A walbro 255 pump requires a afpr. Your stock fpr is being over run.

Indeed it does, Yet People have been doing it without and claim to have no issues.

 

[95'RS-T]

Indeed it does, Yet People have been doing it without and claimed to have no issues.

I have read that as well but he is also running 1000cc injectors.

 

[miguelmcv]

2 on what 95'rst said, you need an aftermarket fpr for a 255 walbro.

 

[BIRDCLAWTSi]

2 on what 95'rst said, you need an aftermarket fpr for a 255 walbro.

It crossed my mind as well. Anything is possible.

 

[DSM_Newblet]

I would look into the ignition stuff first, Spray water on the wires and coils and see if it acts up, And look for sparks. Let it cool down and check the spark plugs. Not sure why shutting it off would help. Do you hear clicking or anything from inside the car wierd smell?

Yeah it does get a weird smell and and a lot of clicking and vibrating. Almost like detonation or one of the cylinders just dies off. I've talked to alot of people about afpr and they all said I would be fine without one but if you guys think it could be part of the issue then I will look into getting one if I really have too.

 

[MakeItHappen]

for the over heating it can be a couple of things, such as bad water pump, bad hoses, radiator cap, or even head gasket. do a leak down test. then eliminate that problem. oh and do a compression test while you are there, check the timing. just a list of things i would go over.

how about how to check most of these problems,
for the water pump, unhook the hoose that goes to from the pump to the radiator and aim it in a bucket then turn the car on, if it does what the pump is supposed to then you may end up with wet feet

Head gasket, check for oil spills all throughout the area and watch for smoke when you drive

 

[DSM_Newblet]

how about how to check most of these problems,
for the water pump, unhook the hoose that goes to from the pump to the radiator and aim it in a bucket then turn the car on, if it does what the pump is supposed to then you may end up with wet feet

Head gasket, check for oil spills all throughout the area and watch for smoke when you drive

It's a new water pump and head gasket. The car doesn't smoke and has one tiny oil leak because the guy who did my oil pan gasket was a dumb ass. I'm not too worried about the over heating because I'm pretty sure it is the fans. My main concern is the engine and the sounds it's making and the way it's running.

 

[LOLVTEC]

Do your fans turn on when they should. And when you say overheating what are the temps?

 

[triggerx]

you try a new ecu yet?

My 90 sounded like a lawnmower occasionally, and was sometimes throwing a cel though. turns out the ecu went bad.
The ecu going bad isnt always its either bad or good. The problems can be intermittent as well. And since the ecu controls the fuel injectors its possibly the ecu. Ive learned just to keep a spare to diagnose problems like these

 

[DSM_Newblet]

Do your fans turn on when they should. And when you say overheating what are the temps?

Sometimes and my exhaust manifold glows red so I imagine it gets VERY hot

you try a new ecu yet?

My 90 sounded like a lawnmower occasionally, and was sometimes throwing a cel though. turns out the ecu went bad.
The ecu going bad isnt always its either bad or good. The problems can be intermittent as well. And since the ecu controls the fuel injectors its possibly the ecu. Ive learned just to keep a spare to diagnose problems like these

I replaced my stock ecu with a 91 eprom ecu since I have a 6 bolt in the car. How can I test if it's good or bad?

And not that you mention it, the problem never occured with my stock ecu...

 

[slayer450]

Sometimes and my exhaust manifold glows red so I imagine it gets VERY HOT.

Manifold glowing red makes me think it running lean.

 

[DSM_Newblet]

Manifold glowing red makes me think it running lean.

It is running very lean when the car does the weird thing it does but other then that when the car is running normal and I boost then it runs really rich and really lean at idle but if I'm just cruising it's at 14.7 A/F R.

 

[slayer450]

Throw an afpr on it, your fuel pressure is probably all over the place.

 

[LOLVTEC]

Manifold glowing red makes me think it running lean.

are you having mis firing issues?

 

[LOLVTEC]

Throw an afpr on it, your fuel pressure is probably all over the place.

Some people get away without an afpr. my friend ran 2 225 Wally and inline.Bosch pump with 2000+cc injectors and used the stock fpr. But he has very well tuned on e85

 

[ramsack]

Most people have the problem with FPR overrun on the HP pumps more than just the regular 255. Large injectors don't save you from overrun. They only use that much fuel at WOT at high RPMs. They will not change how the FPR acts just putting around town.

 

[DSM_Newblet]

are you having mis firing issues?

Yes or atleast it sounds like a constant misfire from just one cylinder. I loss power as if I'm running off of 3 cylinders.

Throw an afpr on it, your fuel pressure is probably all over the place.

What should my fuel pressure be at?

 

[95'RS-T]

Base fuel pressure for a 2g is 43 psi.