Hessitation past 4K RPM.. Help..

[BMWLOCO]

Fellow Enthusiasts:

Stock M20 that when I go WOT in 2nd gear, I get major hesitation past 4K RPM and engine bogs down until I let go of the pedal.

Here's what I've replaced so far:
- Cleaned ICV
- Replaced the Crank Position Sensor (yesterday)
- Spark Plugs less than 1K new
- Wires new
- Replacement Fuel Pressure Regulator (maybe a new one needed)

I'm thinking Injectors.. (They are at least 200K old)
If so, which ones should I buy?

I put in the ebay chip and the problem was still happening BEFORE the chip.

Thoughts..

Thanks in advance..

[jlevie]

Check the TPS. The WOT switch may be bad. Then check rail fuel pressure while driving the car when the problem occurs.

[paperplane94]

Fellow Enthusiasts:

Stock M20 that when I go WOT in 2nd gear, I get major hesitation past 4K RPM and engine bogs down until I let go of the pedal.

Here's what I've replaced so far:
- Cleaned ICV
- Replaced the Crank Position Sensor (yesterday)
- Spark Plugs less than 1K new
- Wires new
- Replacement Fuel Pressure Regulator (maybe a new one needed)

I'm thinking Injectors.. (They are at least 200K old)
If so, which ones should I buy?

I put in the ebay chip and the problem was still happening BEFORE the chip.

Thoughts..

Thanks in advance..

That screams bad TPS. Test it with a multimeter.

^YOU BEAT ME BY SECONDS :)

[nomansland92]

Most likely tps but give your cap and rotor a check, Also you could check fuel pressure or your fuel flow rate on your return line.

[BMWLOCO]

- New 255LPH High flow Fuel Pump
- New Cap and Rotor a few months ago.

I'll check the TPS..

How do I test it with the multimeter? What am I looking at for "Normal" voltage?

Thanks again..

[paperplane94]

Check out the bentley manual, might be online somewhere.

[BMWLOCO]

UPDATE:

- Got a new OEM TPS installed. Checked resistance per the Bentley.
- Put in some Mustang Injectors.

Still some hesitation after 4K RPM in 1st, 2nd, etc.. at WOT and sputtering unless I release the accelerator.

On the way home after the repair, It died again. I tried to restart again and it took 3 tries and about 2 minutes of cool-down to start back up.

I'm suspecting the Fuel Pressure Regulator.

When it stalls again, I'll pull the hose that sends fuel to the rail and see if there is pressure. If none, fuel pump/filter clogged. If good pressure to that area, I'll pull the return line to see pressure..

Is the DME a possibility?

Thanks in advance!

[E30-325iS]

I don't think you can just put in Mustang injectors, it'll run too rich unless the ebay chip is programmed for 19# injectors. Make sure that when you are measuring the output of various sensors, e.g cts, tps, etc you also measure at the ecu in case the harness is bad. The connector under the intake manifold is notorious for becoming corroded and causing all sorts of problems.
Before replacing anything else go back to stock and measure every thing again, the DME is probably the last thing to suspect.

[BMWLOCO]

I'm swapping the FPR with a friends this AM and will report the findings. Thanks again to all!

[BMWLOCO]

YESTERDAY:

Swapped the FPR from a friends E30 and all sounded good. After I replaced the Throttle Position Sensor with a new one, we dialed it in and voltage is good to go now. Idling is spectacular.

TODAY: Drove it to work. On my way back home, while cruising at 3-4K rpm in 4th,
IT JUST DIES!, I pull over to the side of the road, wait a few seconds and it starts right up. WHAT GIVES!

I was in Air Force Blues and didn't want to get dirty while pulling the lines on the bridge to see if there was fuel pressure from the pump...

Started right up and drove home..

I'm suspecting:
- FUEL PUMP / RELAY ? (Has a new 255LPH pump) ???

So far, New TPS, CPS, newer injectors, and swapped FPR.

I'm stumped!

Thanks in advance!

[dnguyen1963]

Have you checked your ignition coil?

[BMWLOCO]

No, but will do ASAP. Thanks..

Still, I'm thinking fuel, but will give it a try...

[BMWLOCO]

UPDATE:

FFWD a month and the car sat for a while because of a few days off and driving the MCoupe.

A few weeks ago, I bought a new IGNITION COIL, and put it in. Drove it for a few days and all went smooth, maybe a fluke. The day before I went on leave, (14 May), I was driving back from work and it died. No more WOT sputtering, but a huge fuel smell.

I parked the car for about 10 days and yesterday I bought a Mustang O2 Sensor and retrofitted it a few hours ago. Car idles well, take it out for a drive, and a few WOT runs, pull the corner around the house and the car dies again. No sputtering, just dash lights on, and it doesn't want to start again.. Cranking, etc... but no ignition.

Fuel on the reserve, but I pull the back seat and check for fuel-pump operation and it's turning on, but no start. Let it cool off, and still no start. WHAT GIVES?

The only thing that I haven't replaced in the engine is the plug wires, and the fuel pressure regulator.

Thoughts!

Thanks in advance..

[dnguyen1963]

Pull the plugs when your car dies...I bet they are completely wet because of the 19# injectors.

[I got it, yes!!]

did you try changing the main relay? just a thought, but i had one go bad intermitantly and it had the same effects your describing.