Hard to start
Thread Starter
Seasoned Member
Joined: Dec 2009
Posts: 429
Likes: 0
From: Wichita, KS
Year: 1999
Model: Cherokee
Engine: 4.0l I6
So my Jeep is hard to start. It doesn't matter if its warm or cold its a little tough. Basically I start to turn it over then pump the gas and then after about 5 rotations or so it will start. What causes problems like this? I know that it does start no matter what but seems to struggle.
CF Veteran
Joined: Jul 2009
Posts: 2,158
Likes: 11
From: Chico,ca
Year: 89
Model: Cherokee
Engine: 4.0
Next time just turn your key on about 3-4 times before you try and start it,that way the fuel rail will be charged,if it starts quicker then it would be your fuel pump allowing fuel to drain back to the tank.
Mine was taking a long time to start and I just put a new battery and starter in it and it starts fine now,your cps has to see the engine turn over fast enough to be satisfied,a starter dragging or low battery can also cause this.
Mine was taking a long time to start and I just put a new battery and starter in it and it starts fine now,your cps has to see the engine turn over fast enough to be satisfied,a starter dragging or low battery can also cause this.
You also have to remember that its a renix. The ecu was made by an aeronautics company (bendix) so it has some weird parameters before the engine will start.
The ecu has to see at least 300rpm at the Crank, and some people say it also has to see a minimum oil pressure. Once these parameters are met, the ECU will Send fuel and spark to the cylinders, starting the engine.
Just as regular maintenance I would get your battery load tested. It doesnt cost much and I would do it about once a year. Also, check to make sure all your electrical connections are good. The ground strap on the head of the engine that goes to the firewall is known to get corroded and cause electrical resistance, it is recommended that you replace it with a heavy gauge THIN STRAND (for flexibility and amperage capability) wire, about 2Ga or bigger..
Alot of people also run a secondary ground wire from teh battery to the radiator support, about 4gauge. This secondary wire made my battery guage more accurate and also lowered my starting time. You also have to remember tht it is a 20yr old engine and computer. The compression is pry starting to go down if your high on miles, this will increase fuel usage and starting time..
The average starting time for mine is about 5-10 seconds of cranking with a high of 15-20 seconds on a bad day. This is considered normal for most Renix engines.
Hope this helps,
Dylan
The ecu has to see at least 300rpm at the Crank, and some people say it also has to see a minimum oil pressure. Once these parameters are met, the ECU will Send fuel and spark to the cylinders, starting the engine.
Just as regular maintenance I would get your battery load tested. It doesnt cost much and I would do it about once a year. Also, check to make sure all your electrical connections are good. The ground strap on the head of the engine that goes to the firewall is known to get corroded and cause electrical resistance, it is recommended that you replace it with a heavy gauge THIN STRAND (for flexibility and amperage capability) wire, about 2Ga or bigger..
Alot of people also run a secondary ground wire from teh battery to the radiator support, about 4gauge. This secondary wire made my battery guage more accurate and also lowered my starting time. You also have to remember tht it is a 20yr old engine and computer. The compression is pry starting to go down if your high on miles, this will increase fuel usage and starting time..
The average starting time for mine is about 5-10 seconds of cranking with a high of 15-20 seconds on a bad day. This is considered normal for most Renix engines.
Hope this helps,
Dylan
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