Really weird please give YOUR advice

[mustangfan1990]

Ok I put the 2.75 pulley on today and it hit 13 lbs in 2 gear and like 9 lbs in 3rd. Ok I live in the HIGH foothills of NC and I went to Hickory which is about an hour from me and the elevation is lower. I am not sure about how much. But I went to get on my car to merge on to the interstate and I had it in 3rd and as the rpms clibm so does the boost but after like 4500 it keeps making boost (the engine has a different sound when it is making boost) and the engine sounds like it did before only the car quits pulling as hard and seems like it is struggling to accerate. The rpms and boost are both going up just seems like the car lost ALOT of power. So I tried in 4th and same thing. Then I tried it in 2nd and it did it in 2 nd too. I was like OMG I ****ed up my engine. So I was talking to some friends and gave the car a rest and on the way home I hit in 2nd and the power was back in 2nd it seemed but not in the other gears. I dont think the elevation is that much difference. There is a difference but I dont think alot. I was wondering did I blow a head gasket or something or it is just blowing my spark out or possibly a fouled plug. It is hard to hear a miss in my car because of the HUGE lope that it has. As long as you dont take the boost real high 4-7 lbs and you dont rev the engine high it feels strong but it gets weak when you really turn the rpms.....any ideas guys PLEASE HELP.....VERY WORRIED. Only 1 week until tune and I worried I ****ed my engine up before the tune and will have to reschedule

 

[Rick 91GT]

Since the boost is climbing I would say it is not belt slippage...

Easiest things to check first, plugs, make sure all your tubing connections are tight if one came loose but stays inline it will kill the power. If your blowing the spark out it usually doesn't act different in different gears.

I would run a .035" gap, what plug are you using a 3923?

 

[mustangfan1990]

yeah. I have them gapped at .35 if revs up and everything sounds right. It is like the clutch is slipping but I know it isnt. I can feel the power start climbing and then it is like at a certain rpm it just quits pulling but the rpms are climbing and the boost is too

 

[mustangfan1990]

tt

 

[Rick 91GT]

It could be a fuel delivery issue, you basically have to start fresh and check all the vitals. Pull all the plugs, while they are out I would just swap them with new ones, double check the base timing or timing retard if you have a BTM, you could do a comp and leakdown test as well. Does the car have a chip or other piggyback system for tuning?

Since you say it has a different sound when it is no building boost maybe the blow off valve is not holding, check the vac line from it? It is most likely slipping in the higher gear when the load is on the motor hence the reason you are only seeing 9psi. Can you see belt dust all over your hood or motor?

 

[Vipersix]

It could be so many different things that it's difficult to tell you where to start looking. Your description may sound reasonable in your own head but I can't figure out anything from it. I would begin as Rick suggested, check the vitals. Timing, fuel pressure, electrical connections, plugs, the whole nine yards.

In the future, I would recommend against "getting on it" before you do a sufficient tune. Too much boost can very easily destroy an engine.

 

[mustangfan1990]

It could be so many different things that it's difficult to tell you where to start looking. Your description may sound reasonable in your own head but I can't figure out anything from it. I would begin as Rick suggested, check the vitals. Timing, fuel pressure, electrical connections, plugs, the whole nine yards.

In the future, I would recommend against "getting on it" before you do a sufficient tune. Too much boost can very easily destroy an engine.

yeah well it wont be drove again till this friday and that is when I get my tune. I just everything sounds fine except sowhat of maybe a lean pop. But it woasnt doing it acouple of days ago. When you try to accelarate at half throttle it feels REAL strong but when it starts making boost and you are trying to turn the RPMS it starts popping and the rpms and boost still climbs but the car doesnt accelarate like it was. It feels like it is pulling something and struggling

 

[Foxfan88]

just wait and see what the tune does for you. if its a good accurate tune you will be amazed at the difference, both in power and drivability.

 

[Stang2Man]

Have you got a fuel pressure gauge or any kind of air/fuel gauge on it? When we put the procharger on my brothers' 98 Convertible it did the same thing, but we wanted to play with the car before we put the fuel pump, and it just choked, air/fuel ratio went lean and the car was absolutely flacid. Put fuel pump on and he got the tune a few weeks later, the car still runs great with over 130K on the clock.

 

[mustangfan1990]

well My fuel pressure goes to 70 under boost almost immediately and it has a 255 inline t-rex. it is getting plenty of fuel

 

[millhouse]

well My fuel pressure goes to 70 under boost almost immediately and it has a 255 inline t-rex. it is getting plenty of fuel

So I take it your running a FMU instead of upgraded injectors and MAF?

 

[1991vert]

does it seem like clutch slippage? do the 5th gear test and floor it. see if the rpm's climb and the car doesnt go very far

 

[mustangfan1990]

It does seem like the clutch is slipping but kind of doesnt..........and I am upgrading to bigger injectors but Icant run 42s without a tune. Dan's shop is almost 2 hours from me. I could see me trying to drive that gas hog with 42's 2 hours without a tune. He told me to wait and me and him would put them in when I get down there

 

[millhouse]

It does seem like the clutch is slipping but kind of doesnt..........and I am upgrading to bigger injectors but Icant run 42s without a tune. Dan's shop is almost 2 hours from me. I could see me trying to drive that gas hog with 42's 2 hours without a tune. He told me to wait and me and him would put them in when I get down there

What is your current setup?

If you upgraded to 42's along with a matching MAF, you would be fine driving it there without a tune. I wouldn't necessarily push it to the limits without a tune, but driving it to the tuner is absolutely do-able.

 

[mustangfan1990]

I have 24s in it now with an FMU, but I have brand new 42s sitting on my table with a pro-m 80mm MAF.Dan said it would run but like **** and it would get HORRIBLE gas mileage. Right now if I dont get on it it gets decent gas mileage

 

[millhouse]

I have 24s in it now with an FMU, but I have brand new 42s sitting on my table with a pro-m 80mm MAF.Dan said it would run but like **** and it would get HORRIBLE gas mileage. Right now if I dont get on it it gets decent gas mileage

I don't know why he would say that…but as long as you ditched the FMU, you'll be fine. Hell, there are guys running around with no tune at all and the upgraded MAF and injectors who are perfectly happy. I myself had once run 42lb injectors with a matching MAF and no tune (with my turbo) and has great drivability…and good fuel economy. It ran a bit rich at WOT…but besides that, it was fine. I'm not condoning running without a tune…I'm just saying you should have no issues getting there, and your fuel economy really shouldn't suffer that much at all.