Z dies during high speed acceleration

[dogma420]

Possibly somebody put something in your gas tank...and it is blocking the fuel uptake...something like a sticker, I've heard of it happening. If it dies, go ahead and shake the rear end up and down to possibly 'dislodge' whatever is in the tank blocking...it's worth a try. Right after shaking the rear end, if the car starts right up, that's the problem.

[cj71z]

Thanks for all the great advice, I installed my new fuel pump and noticed a couple other problems. I noticed that my distributor was installed backwards and that my breaker plate was stuck in the advanced position due to the last ball bearing wedged between it. I took apart my distributor, cleaned it up remounted it correctly put back the cap and she fired right up. I'm thinking about bypassing vacuum advance till I can find one. Are breaker plates for zx distributors still available anywhere? Anyway I had to order a new thermostat housing cover since mine cracked in half overnight, another 15$. So far I haven't noticed any fuel problems, my new guage reads around 3-5psi at idle and around 4 when I rev her up. Hopefully this weekend I'll get her on the road and test her out to see if the problems been solved.

Chris

[millerje01]

Thanks for all the great advice, I installed my new fuel pump and noticed a couple other problems. I noticed that my distributor was installed backwards and that my breaker plate was stuck in the advanced position due to the last ball bearing wedged between it. I took apart my distributor, cleaned it up remounted it correctly put back the cap and she fired right up. I'm thinking about bypassing vacuum advance till I can find one. Are breaker plates for zx distributors still available anywhere? Anyway I had to order a new thermostat housing cover since mine cracked in half overnight, another 15$. So far I haven't noticed any fuel problems, my new guage reads around 3-5psi at idle and around 4 when I rev her up. Hopefully this weekend I'll get her on the road and test her out to see if the problems been solved.

Chris

cj71z,

I am having the same problem you described. It runs fine at idle but then it bogs down after about 5 to 10 minutes on the road. The engine starts running real rough and makes a sound like its getting too much fuel (flooded). Once the problem occurs the engine will not exceed 2500 to 3000 RPM.

When car is allowed to return to idle, it sounds like it is going to die but idle stabilizes at around 900 to 1000 RPM.

Car feels like it is getting too much fuel

Car fails emissions test with HC and CO2 readings that are twice the allowed limit. This leads me to believe it is running way too rich.

Carbs have been leaned out as much as possible and still have it run.

What did you conclude was the cause of this problem?

[ljconwell]

Please let me know what worked on your cars as I'm having the same probblems.

Thanks Larry

[cj71z]

I'm not sure if I've figured it out yet. I thought it was a fuel problem, but now I'm thinking it's an electrical problem. I hooked up my timing light on #1 and took note of the spark timing. The spark seemed strong, but seemed like there was interference. I moved the other wires and the timing was more pronounced. I need new wires. Then I attached it to my coil wire and took note. The light is consistent, but intermittently misses at idle. I increased the RPMs and took note also. At about 1500 and above or so the light seems to get noticably dimmer with inconsistent bright spots. Now I'm thinking coil or possibly alternator. I got in the car and repeated the same test. I noticed my amp meter reading steady a little above middle at idle. When I increase the RPMs to around 1500 the meter jumps up and holds steady, at 2500 the needle jumped up and down a couple times, and at 3000 the needle seemed steady, but inconsistently up and down a bit. I let it return to idle and the amp meter began to jump around in the middle as it was missfiring. I'm thinking it's the alternator, not sure how old it is, but it has to be at least 10 yrs old. The coil is new and my distributor is in decent shape. 2 stator/reluctor points seem to be close, but do not touch. Any ideas on my findings fellow Zed Heads?

Chris

[cj71z]

Car fails emissions test with HC and CO2 readings that are twice the allowed limit. This leads me to believe it is running way too rich.

Carbs have been leaned out as much as possible and still have it run.

Have you rebuilt your carbs? If you haven't then I would do so. Removing 30 plus years of gunk, new gaskets, needles, nozzles etc. will do wonders. Make sure you get your float levels correct as it'll make adjustments easier. I felt I had a vaporizing issue because of wandering mixtures on my carbs. I bypassed the hot water to the intakes and it seems like it's gone. Your problem seems similar to mine, keep me posted with your findings as well.

Chris

[Freerider]

millerje01,

I'd lower the float height (less gas) and see if that helps, its a 30 year old car, you cant always go by what the manual says.

[cj71z]

Update:

I finally got to work on my car today. First I stopped by Z-parts and saw Eric for a 3 core radiator and a shroud, got a good deal on a used one. I bought new plugs and brought my new parts for my distributor. Changed out the radiator, installed plugs, changed breaker plate, and raised the float level. She fired right up after a good warm-up confirmed no leaks in radiator, then readjusted timing and carbs. Went out for a test run and you know what problem seems to have disappeared . Ran her hard in third, shifted to fourth and everything was great. Drove her for 2 hrs around town and on the highway and problem never appeared. Finally have confidence to drive her again. Thanks to everyone for the help.

Chris

[e_racer1999]

great to hear it! you've been wrestling with the beast for some time now...