Bucking / No Throttle after 1500 RPM.

[Ray$]

Just a quick update for anyone having this issue.

After more than a week of having the TPS swapped out and driving hard to try and instigate the issue, nothing. Seems to me that the issue did revolve around the throttle position but keep in mind that there may have been multiple issues that I rectified all at once with all of the parts I had been swapping in. Hopefully this info helps someone out there with this type of problem.

[e30sh]

I installed my new TPS (damn m20 engines having it on tbe bottom is such a pain) but now I'm idling at 2k rpm. I know this is just a poorly installed TPS but I had a concern...

When adjusting the tps, do I tighten it ON the click for closed throttle? I was informed to have it set just before the click but am unsure based on some searching. I know most everyone says to test it with a multimeter but having this thing on the bottom of the throtttle body is tough to hold the tps, throttle and the multimeter
Anyone have any suggestions that don't involve having to remove the throttle body entirely?

You can adjust it on the car with the boot removed and the right screw driver.

The click should be just off idle. You can put your meter in beep mode. Center contact and idle contact should beep until you step on the pedal a bit. Center and the other outside contact should beep near full throttle.

[Ray$]

So I have had the car on the road for 3 days and after swapping and properly calibrating the TPS and cleaning the throttle body and ICV the car runs incredible. I should have listened to my gut (and the collective internet) and looked into the TPS earlier. There is a chance that my original issue in my first post was a combination of problems due to the symptoms changing a few times but either way problem solved......for now.

Thanks to everyone who hooked it up with the knowledge. :D

[audiquattrot]

AFM if everything else in your list is good and properly working

[Ray$]

I installed my new TPS (damn m20 engines having it on tbe bottom is such a pain) but now I'm idling at 2k rpm. I know this is just a poorly installed TPS but I had a concern...

When adjusting the tps, do I tighten it ON the click for closed throttle? I was informed to have it set just before the click but am unsure based on some searching. I know most everyone says to test it with a multimeter but having this thing on the bottom of the throtttle body is tough to hold the tps, throttle and the multimeter
Anyone have any suggestions that don't involve having to remove the throttle body entirely?

[grimm]

Looks and sounds similar to an issues i was having. Throttle Position Switch seemed to help, I also swapped throttle cable and all the grommets at the same time and cleaned the ICV. the cable and grommets did make a world of difference with engine response. I don't think the crank position sensor would give you these symptoms.

[Ray$]

I do have 173 DME and have pulled the codes in the past so yes it is strange for my car. Still waiting on my part but so far so good, no issues driving with TPS unplugged (only necessary driving).

[Northern]

So I just found something odd. Tried to pull the Motronic codes (stomp test) and after the 5 Wot stomps I get......nothing.

Only odd if it's a 173 DME (or equivalent)... lots of 153 cars out there too.

[Ray$]

I am waiting on my new throttle position switch to arrive. Once it does I will provide any more info that I can but I am doing only necessary driving with my TPS unplugged and so far so good. Part arrives on Monday so keep yours eyes out for my update.

[cobraken]

I also have a misfire that sounds similar to this. I have already changed MAF, Plugs, CPS, Wires, Cap and rotor. I'm interested to see if you find a solution to the problem.

[Ray$]

So I just found something odd. Tried to pull the Motronic codes (stomp test) and after the 5 Wot stomps I get......nothing. I know the computer relies on Wot to send the signal. Could this mean bad TPS? We ruled out TPS the from the intermittent problem just based of my mechanical consultants experience but maybe we need to revisit it?

Update 1: After the dizzy cap and rotor swap, car runs incredible with no issue SO FAR. The problem has in the
past gone away for several days and come back so I am not getting too excited yet.

Update 2: Did the dizzy cap on Sunday. Tuesday morning now and rather than losing throttle, I let my foot off the gas and the throttle (not the pedal) got stuck! Looks like this issue is showing itself in many forms but I am leaning towards the TPS more than ever. I unplugged it and made the trip to work safely with no issue. Going to get a new one shipped asap and will report back.

[YosemiteSam]

Also could be your AFM. Old AFM's can drop the signal intermittently when the resistor strip wears out and then the PCM cuts fuel.

[Ray$]

Swapped out Dizzy cap and rotor and both look super worn. Going to give her a few days and see if it takes.

To answer above concerns, fuel pump, filter, regulator and all hoses checked. Everything is either in good shape or new.

Crank position sensor changed already - no change.

Tps is a good idea if it comes back.

I'll reply within a few days with an update.

[Kershaw]

http://www.r3vlimited.com/board/showthread.php?t=372569

Check everything mentioned in this thread.

[molna]

Seems like we both have kinda same problem, but mine cuts of at around 3k rpm, without the ivc connected the car will rev normally but car will spitt/cut when you drive it on road and give full gas. Spark plugs are black.

How did this happen? Did the car stand still a longer time or have you changed any parts?