If been doing a little digging online about my problem before making this post. I see that this is a pretty common issue and a main fix is to clean all engine to battery grounds. After that I saw a lot about that it was more about hitting a wall and could not go past 4k at all. What my issue seems to be is around 4k it bogs but if I let off the gas like a quarter inch it fixes and keeps going up like normal, but I cannot press that gas pedal farther without it bogging. The RPM's will climb normally just a slower rate from the gas pedal only being at about 40%-50% I would say. I used some injector cleaner to see if the secondary injectors were a little clogged or something and it seemed to help a tiny bit if at all. I also read that its possible that my OMP may be out. My next fill up I'm going to add 6oz of premix to a full tank and see if that helps at all. Anything else I should check or look into??

 

Is this a turbo or NA motor, and what year is the car? In addition to cleaning the grounds, early turbo cars benefited from adding a ground to the boost sensor. I believe it was part of a factory TSB/revision that came later. I would suggest searching for that and see if it applies to your vehicle. I am fuzzy on the specifics as to applicable year/model.

have you changed the fuel filter (both the pump sock and the external filter)?

finally I believe you’re referring to limp mode on the S5 since you’re talking about the OMP. If the car was in limp mode, it would drive pretty poorly; I don’t think your symptom correlates. Plus you would have a CEL.

 

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My mistake! 1990 NA Standard transmission. So not a boost issue

 

I have not changed the the fuel filters yet. I found a "tune up" kit that has all the filters thats currently in the mail. I got the car about a week ago. I do have a CEL but the code will not read. The only time it read it said OMP then it wouldnt pop up again.

 

Im going to buy the Atkins rotary tune up kit and block off plates from banzai and see where that gets me.

 

So my NA didn't do the "hit the wall" thing at first. I had 3800 hessitation. I later learned that my injectors were high impedance injectors instead of the needed low impedance ones so I bought some OEM ones from a friend. I installed them and then I got the "hit the wall" symptoms. I sent the injectors to get professionally cleaned, got them back on spec and threw them on and problem fixed. So for me it was wrong/ dirty secondary injectors.

The reason why your car feels normal again if let off is because at 3800 rpm is when your secondary injectors fire on 50% cycle and your primary go to 50% as wel . So you're instantly hitting that wall only getting half fuel. When you let off, it goes back to just the primaries and feels normal again. Hope this helps.

 

Where did you send them off to? I think I'm going to end up needing to get them cleaned. I mean couldn't hurt right

 

I'll have to look for where I sent them. I think it was a local place out here in AZ. They did an amazing job and went above and beyond to do ultrasonic cleaning. They said they were real bad and required multiple passes to get them back to spec. I think their name was like 3 letters or something, I'll look them up. Also, I didn't mention but it was just my secondary injectors that were giving me issues so I only got those 2 cleaned since they are super easy to access . The 2 primaries require more work to get to so I didn't do those. If you're able to do all 4, do it. But for me, the two secondaries were easy to access and those were the ones I needed to replace anyway.

 

Witch Hunter Performance is one of, if not the best in the business and have been doing it for a long time. I use them exclusively. Price is right in line with all the other major players such as Injector Rehab, RC, etc.

 

I have used Witchhunter and they do great work!!! In fact I'll be sending them another set here next week. Its about a week turnaround time.

Have you inspected and cleaned your grounds under the hood? This is a good idea if they have never been cleaned. Ensure the pins are clean and pin fit is good and make sure the threads are clean for the bolts securing single ground wires and ensure the terminal end is clean. Also, what part of Ohio are you in?

 

I just got my secondary injectors triple cleaned and it did not fix it. Actually it didnt bog once up to 8k then after that the bog came back. After this didnt work, I added a new ground to the strut tower for the pressure sensor. After doing this I found out that my CEL light would now turn off and on whenever it wanted to. Before my CEL would be on when I started my car. Now it will be off, turn on while driving and just turn off at stop signs and such. Also I'm from Lima !