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-   -   at wits end (https://www.rx7club.com/new-member-rx-7-technical-256/wits-end-1057989/)

lodown88 02-24-14 12:52 PM

at wits end
 
Working on 1988 n/a, 13b, 6 port. Car has sat up for a year until I rescued it. Will crank but dies after 2-3 seconds. Replaced fuel pump, fuel filter, afm, battery and checked for vaccuum leaks. To my amazement still will not run. Any help would be greatly appreciated as I have read every technical forum on here.

TerryD 02-24-14 10:20 PM

adjust the tps? will it stall if you give throttle?

misterstyx69 02-24-14 10:24 PM

what do you mean dies after 3 seconds?.like stops cranking or starts up and then dies?

RobbyWally 02-24-14 10:50 PM

So many possibilities. Bad gas. Dirty fuel tank & blocked low pressure screen at the fuel pump. Dirty injectors. Any number of possibly mis-adjusted or not working parts / sensors related to cold idle.

If you can keep it running by giving it throttle until it warms up at least you could determine if the problem is only cold idle or idle in general. Also, there are some things you can check / adjust even if the engine isn't / won't run. For example, there are contacts in the air flow meter that enable the fuel pump to run. The idle mixture 'variable resistor' can be set to the midpoint, etc. Fill us in on some details and we will try to help.

lodown88 02-25-14 10:34 AM

The car will start and sounds strong for a few seconds then dies. I've tried giving it throttle it makes it die quicker. Gas tank is brand new..all old lines replaced..new high octane gas..new mass air flow sensor installed..new plugs and wires

lodown88 02-25-14 10:39 AM

I will greatly appreciate any help with this..no mechanics within 100 miles. All I havevis this forum and a haynes repair manual.

misterstyx69 02-25-14 11:13 AM

One thing is if your AFM( air flow meter) is not connected properly,the car will start but die very shortly after.It will do this Over and over UNTIL you plug in the AFM.

deanofay 02-25-14 02:42 PM

I believe I read someone if you have the fuel lines reversed it could cause it to run then stall after a few seconds. Might want to check that just in case

lduley 02-25-14 03:32 PM

Have you tried oil in the motor? Rotarys don't like sitting for periods of time, you may have a sticky apex seal

lodown88 02-25-14 04:25 PM

I did take the plugs out and put about 3 cc of marvel mystery oil in and let it sit overnight.Iknow once I did that I wowould have to probably get new plugs. About to throw in the towel with this car.

DC5Daniel 02-25-14 05:57 PM

Theres been a few good suggestions made such as adjusting TPS and also anything related to the AFM; I would investigate both these options with a multimeter.

First, have you verified that the fuel pump is receiving power? Monitor voltage at the fuel pump while a friend starts the car. If voltage cuts out right before the car dies, you've got an issue with your AFM/fuel pump relay. The relay is located to the right of the steering column. When the AFM detects airflow it sends signal to trigger the relay, sending power to the pump. You can jump this relay temporarily to see if it resolves your issue.

Secondly, the TPS is a very important input to the ECU. Out of whack TPS's can cause all sorts of problems from stumbling to stalling. Test the sweep of the TPS resistance to ensure it is linear and consistent (no dead spots). If that's good, proceed to roughly set it per the FSM.

I know you said you have a Haynes, but I'd strongly encourage you to reference the FSM instead. It's far more comprehensive. You can find it by referencing the 2nd gen FAQ thread. Good luck.

lodown88 02-25-14 07:25 PM

I will certainly try everything you listed first thing tomorrow. Ill post what I find. Thank you for advice

lodown88 03-01-14 06:29 PM

cas
 
Ok believe I found the problem. The cas is missing bolts and lose. When rotated the car will try to run. Does anyone know what TDC is?

DC5Daniel 03-03-14 04:55 PM


Originally Posted by lodown88 (Post 11689721)
Ok believe I found the problem. The cas is missing bolts and lose. When rotated the car will try to run. Does anyone know what TDC is?

What you're looking to do is referred to as "stabbing the CAS". There's details in many threads as well as the FSM, but the gist is you want to pull out the CAS and align the two marking on the bottom gear and CAS shaft. You'll then adjust timing like normal by comparing the marks on the main pulley to the alignment pin for leading/trailing coils.

lodown88 03-04-14 10:06 AM

Problem is there are no marks anywhere on the eccentric pulley just rust lol.

ArmyOfOne 03-04-14 12:28 PM

Look carefully, hit the rear edge of the pulley, closest to the engine with wd40 and wipe it clean.Take some of the rust off with a scotchbrite pad and look for the 2 marks that are about a half inch apart.

misterstyx69 03-04-14 02:21 PM

The main pulley's bolt pattern is a bit "offset".
Meaning that even thought the bolts look like a square 4 bolt pattern,the pulley's holes are actually off a bit so it will only go on ONE way.The correct way,so that you do not screw up the installation and put the marks to a different position when installing the pulley.
So if you have to take it off to find the marks,then it will only go back ON the hub One way.IF you can't place the bolts back in the holes then the pulley is not positioned right.simply turn the pulley until all 4 holes align with the hub holes and "voila"..it is back on correctly.
The marks are at the back edge of the pulley,and there is no TDC marks.
The first mark is 5 Degrees BTDC(before top dead center) for the leading,and 20ATDC(after top dead center) for the trailing plugs on an FC.
If you fire at TDC then you are essentially firing 5 degrees early.

Search Timing Marks,Stabbing CAS in Sec gen Specific.You will find the info.

NOTE!: to take the pulley(s) off you take the 4 10mm bolts out..NOT THE 19mm BIG nut on the inside if the main pulley.That is the Hub nut and thermo oil pellet nut on the E-Shaft.

lodown88 03-05-14 11:14 AM

Still waiting on the new cas to arrive. I found two nicks in the pully that are about half inch apart. The old cas is missing bolts and dented. Anyone know if this could be the culprit as to why the car will crank but die shortly after? I rotated the old one to find rhe sweet spot and she fired, but as cas moved she died.

lodown88 03-07-14 05:46 PM

finally
 
I appreciate everyone's posts..after working for 8 straight hours she fired up after "stabbing" the cas. We had flames coming from exhaust and ideling issues but running none the less. Hardly and power but have new plugs ordered for her. I'm very excitedthat after a long month she's running.

DC5Daniel 03-08-14 08:20 AM


Originally Posted by lodown88 (Post 11693743)
I appreciate everyone's posts..after working for 8 straight hours she fired up after "stabbing" the cas. We had flames coming from exhaust and ideling issues but running none the less. Hardly and power but have new plugs ordered for her. I'm very excitedthat after a long month she's running.

Glad to hear, keep us posted once you figure more out.

lodown88 03-09-14 09:12 AM

Alright..the ol girl is running. Have a bit of a problem. I drove it a few miles back home. Lead mechanic at pettit racing said drive her. So up hills the car is lugging actually stalled on a steep incline. Tried to do a compression test but no reading. Guage I borrowed was messed up. Have to have some sort of compression for it to drive. The cats are original and I know there is a vaccuum leak at the lower intake. Any help would be appreciated.


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