88 mazda rx7 wont run

195

Asked by Oct 26, 2010 at 08:35 PM about the 1988 Mazda RX-7

Question type: Maintenance & Repair

won't run for more then 20 seconds, and only off of ether at that. all starting and fuel system sensors check out good. any ideas?

17 Answers

5,345

Have you checked your fuel pump for power and fuelflow, replaced the fuel filter and checked idle settings? It sounds to me like the car's only running on the accelerated warmup system and stalls when that is turned off, this could indicate insufficient fuel supply..

1 of 1 people found this helpful.
195

the fuel filter aint clogged and the pump is able to pressurize the system. is it possible that the pump just can't keep up?

5,345

Check the voltage at the pump, it should be about 12 volts, if not you might try running a power lead directly from the battery to the pump to see if that cures the running issue. In that case a fuel pump rewire might be the best way to go as explained on http://www.1300cc.com/howto/how2/rewire.htm Also check under the car for kinks or dents in the fuel lines which could restrict fuel flow.

5,345

She running again yet?

195

not yet. workin on it though, slowly but surely. i'll post with updates

5

check your starter solenoid and alternator and the main harness for any shorts in the wires

195

update. fuel pump is good. fuel delivery is good. starting system is good. fires off and everything. why won't she run? although, when she fires it sounds like theres a really bad back fire, or wants to backfire. can't tell for sure cause she aint running. ideas?

5,345

Does it smell of unburnt fuel out of the exhauts? If so check your injectors for leaking. Also check the ignition, starting off with the spark plugs (colour and electrode wear, replacing them if they seem dirty is a good idea anyway) then the plug leads (cracks and signs of arcing are a good sign that they need replacing). The coils are fairly bulletproof so they're not likely to be the culprit. Another possible cause you may want to check for is a failing coolant or intake temperature sensor, if either gives a weird reading the ECU might mess up the fuel dosage. Or in the worst case you might want to check the AFM and the BAC valve.

195

theres no strong smell of fuel out of the exhaust. i already checked the resistance on the injectors and replace the o-rings while i was at it. spark plugs was actually the first thing i did. the first set was just old, no abnormal wear and are prolly still good. i bought a new set though just in case. i did check resistance on the leading coil pack. book says there should .1 ohms, there wasn't any resistance. didn't think to check coolant sensor and whatnot though. i'll see if those check out good

45

ok so when a rotary is started up after 20-30 secconds it the elapsed time for it to gain oil pressure(u should know that) ok and if it doesnt smell like unburnt fuel something is wrong these cars run rich by default(duh help lubricate and cool) so he might not be getting enough fuel pressure

5,345

There's rich and then there's RICH, the difference being in a subtle smell of unburnt petrol of great big wafts of fuel vapour coming out the exhaust. Maybe you missed reading the topic as it is cutting out after 20-30 seconds, nothing to do with oil pressure. By the way if it took 20-30 seconds for my TII to get up to pressure I'd start thinking about rebuilding my oil pump, 10 seconds tops is much more realistic on a good pump. As for lubricating... Petrol does NOT lubricate, if you want that go for premix with two-stroke oil or get a diesel engine. It is however very good at diluting and dissolving lubricants, which is why you need to change your engine oil when you get fuel contamination in your engine oil (flooded engines for instance).

195

update. A guy came by and looked at. He says that the fuel system is good. Its just the mass air flow meter/sensor thats bad. its not reading anything and not telling the computer to give any fuel sense theres therotically no air moving to pick up and mix with the fuel. i'mma see if theres a test i can do on the sensor. in the mean time. does this make sense? it does to me, but i'm not too familiar with EFI systems, carburetor are way easier for me.

45

wanna just sell it cuz i am looking for an fc

55

i have an 86 rx7 shell long island ny, cheap and did u ever run an compression test and see if its flooded

45

ur cheap is probably differeny from myn. some info would be nice =)

195

I actually have it listed on craigslist. I strictly deal locally with cars. I don't really want to sell it though, I love workin on stuff like that too mcuh. Especially to sell before I'm done workin on it. I enjoy fiddlin and learning about stuff like this too much.

125

it does make good sense. i would have to check about the 20~30sec shutdown if that is the problem. but for now, sounds like that may be it. please update though, enjoyable reading

Your Answer

RX-7

Looking for a Used RX-7 in your area?

CarGurus has 73 nationwide RX-7 listings and the tools to find you a great deal.

ZIP:

Mazda RX-7 Experts

  • #1
    Lars Cats
    Reputation
    380
  • #2
    tennisshoes
    Reputation
    180
  • #3
    Tom Demyan
    Reputation
    100
View All

Related Models For Sale

Used Toyota Supra
62 listings starting at $5,995
Used Nissan 240SX
6 listings
Used Ford Mustang
589 Great Deals out of 36,206 listings starting at $1,200
Used BMW M3
37 Great Deals out of 2,000 listings starting at $6,995
Used Chevrolet Corvette
185 Great Deals out of 19,817 listings starting at $2,490
Used Chevrolet Camaro
432 Great Deals out of 30,717 listings starting at $2,495

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.